2.2.0

This is a minor release of the SDK with many bug fixes and documentation improvements, along with some new features.

Highlights are listed below, or you can see the full list of individual commits here, and the full list of resolved issues here.

Board Support

The following board configurations have been added and may be specified via PICO_BOARD:

• adafruit_feather_rp2040_adalogger
• adafruit_fruit_jam
• eelectronicparts_picomini_2mb
• eelectronicparts_picomini_4mb
• eelectronicparts_picomini_8mb
• eelectronicparts_picomini_16mb
• olimex_rp2350_xl
• olimex_rp2350_xxl
• sparkfun_iotredboard_rp2350
• sparkfun_xrp_controller
• uugear_wittypi5_hat_plus
• waveshare_rp2350_usb_a
• weact_studio_rp2350b_core
• wiznet_w5100s_evb_pico2

The following board configurations have been modified:

• hellbender_2350A_devboard - Updated for release version of the board

New Features

Encrypted binaries

Support has been added for creating self-decrypting binaries, to make creating and using binaries
with secret/private code easier.

A self-decrypting binary is an encrypted binary with an embedded bootloader that decrypts the main application into SRAM at runtime, and can be utilized via use of pico_encrypt_binary in your CMakeLists.txt file.

See the hello_encrypted and hello_encrypted_mbedtls examples, and section 4.2 of the C/C++ SDK book for more details.

There are two choices of embedded bootloader:

1. A slower, hardened one with side-channel resistance
2. A faster one based on Mbed TLS

NOTE: This feature introduces a breaking change to the pico_encrypt_binary function which now requires an IVFILE in addition to the AESFILE. If you invoke it without an IVFILE (as was the case prior to this release) then you will get the CMake error pico_encrypt_binary Function invoked with incorrect arguments.

Wi-Fi Firmware Partition Support

Support has been added for storing Wi-Fi firmware in a separate partition on RP2350 based boards such as Pico 2 W.

The main binary and the Wi-Fi firmware blob are kept as separate UF2s, to reduce the size of the main UF2 file. This avoids copying the whole Wi-Fi firmware blob on every UF2 upload.

This feature can be enabled by calling pico_use_wifi_firmware_partition in your CMakeLists.txt file. For more details see the documentation for that function in the C/C++ SDK book

New Library

pico_status_led

Most RP2-series microcontroller boards come with either a single-color LED, a multicolored WS2812 LED, or both. The pico_status_led library has been added to simplify dealing with both types of LED, and the complications of the single-color LED being attached to the Wi-Fi chip - not a regular GPIO - on boards like Pico W and Pico 2 W.

• Added status_led_init(), status_led_init_with_context() and status_led_deinit() to perform initialization and cleanup
• Added status_led_supported() to determine if the single-color status LED APIs are available. Note that the single-color status LED is the one specified via PICO_DEFAULT_LED_PIN or the one attached to the WiFi chip on Pico 2 or Pico 2 W
• Added status_let_set_state() to turn the single-color status LED on and/off
• Added status_led_get_state() to get the on/off state of the single-color status LED
• Added status_led_via_colored_state() to determine if the single-color status LED API functions status_let_set_state() and status_let_get_state() can be used to control the multicolor status LED (as is the default on boards with a multicolor LED but no single-color LED)
• Added colored_status_led_supported() to determine if the multicolor status LED APIs are available. Note that the multicolor status LED is the one specified via PICO_DEFAULT_WS2812_PIN
• Added colored_status_let_set_state() to turn the multicolor status LED on and/off
• Added colored_status_led_get_state() to get the on/off state of the single-color status LED
• Added colored_status_led_set_on_with_color() to turn on the multicolored LED and set the color
• Added colored_status_led_get_on_color() to get the multicolored LED "on" color
• Note: pico_status_led is available on PLATFORM=host too, though does nothing

Notable Library Changes/Improvements

hardware_dma

• Added channel_config_set_read_address_update_type() and channel_config_set_write_address_update_type() to surface all four RP2350 address update modes (none, increment, increment_by_two, decrement). The method may be used on RP2040 to set either of the first two modes
• Re-implemented channel_config_set_read_increment and channel_config_set_write_increment using these new methods. This is a minor functional change from the previous release, in that these methods now clear the additional configuration bit added in RP2350 that selects the new increment_by_two and decrement modes)
• Prefer type name dma_channel_config_t over dma_channel_config for consistency with other libraries
• Updated the documentation for dma_channel_set_transfer_count(), dma_channel_configure(), dma_channel_transfer_from_buffer_now and dma_channel_transfer_tobuffer_now to make it explicit that these methods take a 4 bit mode and 28 bit transfer_count on RP2350 vs a 32 bit transfer_count on RP2040
• Added dma_encode_transfer_count(), dma_encode_transfer_count_with_self_trigger() and dma_encode_endless_transfer_count() as convenience methods to safely encode the encoded_transfer_count argument to these functions

hardware_gpio

• gpio_acknowledge_irq has been made inline to improve performance

hardware_irq

• Added Arm Cortex-M33 specific interrupt stubs (weak) that the application can override (isr_memmanage, isr_busfault, isr_usagefault, isr_securefault, isr_debugmonitor)
• Added code to (re-)enable interrupts during runtime initialization on RP2350 (in case a previous bootloader stage disabled them)
• Made irq_has_handler() available even when PICO_DISABLE_SHARED_IRQ_HANDLERS=1
• Added PICO_MINIMAL_STORED_VECTOR_TABLE, which can be set to 1 to save space by only storing a minimal vector table in the binary. In this case, add any exception or IRQ handlers to the RAM vector table at runtime
• Added PICO_NUM_IRQ_HANDLERS, which can be set to the number of IRQ handlers you want in either vector table. This can save space in the vector table if you know that you don't need higher numbered IRQs

hardware_flash

• flash_range_erase, flash_range_program and flash_do_cmd now preserve the QSPI pad state over flash access calls
• Added flash_start_xip() to explicitly perform a first-time XIP setup (including initialising pads) similar to that which would be done when entering a flash binary via the bootrom. This is mostly useful for no_flash binaries that access an attached external flash

hardware_pio

• Allowed pio_encode_sideset_opt(0, value) which is a valid instruction encoding

hardware_powman

• Fixed a bug that made powman_timer_set_1khz_tick_source_gpio() and powman_timer_enable_gpio_1hz_sync() work incorrectly depending on which GPIO was used
• Fixed a bug in powman_get_power_state() which meant that the state bits were returned inverted
• Fixed a bug in powman_timer_set_1khz_tick_source_lposc_with_hz() and powman_timer_set_1khz_tick_source_xosc_with_hz() which caused them to mangle the low 3 decimal digits of the specified source frequency
• Improved the validation and handling of various powman_configure_wakeup_state() state transitions

hardware_rcp

• Added rcp_is_true() which is safe on code that might run on RISC-V as opposed to value == RCP_MASK_TRUE which isn't

hardware_watchdog

• Added watchdog_get_time_remaining_us() to complement watchdog_get_time_remaining_ms()
• Fixed watchdog_get_time_remaining_ms() to return milliseconds instead of microseconds

pico_aon_timer

• Fixed a bug in aon_timer_get_time() on RP2040 related to handling of Daylight Savings Time which meant that time could randomly be off by one hour

pico_async_context

• Fixed an incorrect assertion when using pico_async_context_threadsafe_background from both cores
• Fixed a race condition in async_context_execute_sync() when using pico_async_context_threadsafe_background that might cause an assertion
• Fixed a race condition in async_context_deinit() when using pico_async_context_freertos that might cause an assertion
• Added support for FreeRTOS' configSUPPORT_STATIC_ALLOCATION=1 when using pico_async_context_freertos

pico_binary_info

• Fixed compilation when used by C++ code

pico_bootrom

• Add rom_pick_ab_partition_during_update function to provide a wrapper around rom_pick_ab_partition, which is safe to call before calling rom_explicit_buy during a Flash Update boot or TBYB boot. During development, rom_pick_ab_partition_during_update was named rom_pick_ab_update_partition; backwards compatibility with this name isn't preserved

pico_bootsel_via_double_reset

• Fixed the implementation on RP2350

pico_btstack

• Added CYBT_ERROR_ENABLED, CYBT_INFO_ENABLED, CYBT_DEBUG_ENABLED for finer logging control
• Fixed btstack_cyw43_deinit() to properly clean up the underlying async_context via a new btstack_run_loop_async_context_deinit() method
• Moved the default location for Bluetooth-related flash storage backwards one flash sector from the end of flash so that it no longer uses the last sector of flash, which can be overwritten by the workaround for erratum RP2350-E10
  ...

2.1.1

This is a minor release of the SDK with many bug fixes and documentation improvements, along with some new features.

Highlights are listed below, or you can see the full list of individual commits here, and the full list of resolved issues here.

Board Support

The following boards have been added and may be specified via PICO_BOARD:

• sparkfun_iotnode_lorawan_rp2350
• waveshare_pico_cam_a
• waveshare_rp2040_ble
• waveshare_rp2040_eth
• waveshare_rp2040_geek
• waveshare_rp2040_matrix
• waveshare_rp2040_pizero
• waveshare_rp2040_power_management_hat_b
• waveshare_rp2040_tiny
• waveshare_rp2040_touch_lcd_1.28
• waveshare_rp2350_eth
• waveshare_rp2350_geek
• waveshare_rp2350_lcd_0.96
• waveshare_rp2350_lcd_1.28
• waveshare_rp2350_one
• waveshare_rp2350_plus_4mb
• waveshare_rp2350_plus_16mb
• waveshare_rp2350_tiny
• waveshare_rp2350_touch_lcd_1.28
• waveshare_rp2350_zero

The following board configurations have been modified:

• adafruit_feather_rp2350 - Increased the XOSC startup delay
• seeed_xiao_rp2350 - Increased the default SPI clock divider
• waveshare_rp2040_lcd_0.96 - Renamed WAVESHARE_RP2040_LCD_* constants to WAVESHARE_LCD_*
• waveshare_rp2040_lcd_1.28 - Renamed WAVESHARE_RP2040_LCD_* constants to WAVESHARE_LCD_*

Note: the default PICO_XOSC_STARTUP_DELAY_MULTIPLIER (unless specified by a board header file) has been changed from 1 to 6, meaning a delay of 6ms, as testing of the recommended crystal shows it can take up to this long to stabilize.

200Mhz Clock Support for RP2040

RP2040 has now been certified to run at a system clock of 200Mhz when using a regulator voltage of at least 1.15 volts.

The SDK by default performs clock setup for you before your program enters main(). If you haven't customized the clock configuration in any way, it will attempt to configure the system clock based on the value of SYS_CLK_MHZ (or SYS_CLK_KHZ/SYS_CLK_HZ if specified instead). Without further information from you, it can only do this for specific clock frequencies.

In prior versions of the SDK, only one specific clock frequency was defined per platform, 125Mhz for RP2040 and 150Mhz for RP2350, which also happen to be the default values for SYS_CLK_MHZ

With this version of the SDK, you can now select a 200Mhz clock for RP2040 simply by setting SYS_CLK_MHZ=200 via preprocessor define. The regulator voltage will automatically be raised for you if necessary.

We may certify new frequencies for the different platforms in the future. The original SYS_CLK_MHZ defaults are left unchanged because not all programs would function correctly at a different system clock frequency. If, however, your project would always benefit from the fastest clock, you may now define PICO_USE_FASTEST_SUPPORTED_CLOCK=1 via CMake variable or as a preprocessor define, and it will always use the fastest supported system clock frequency for the platform in the future.

Notable Library Changes/Improvements

hardware_clocks

• Corrected documentation and implementation of clock_configure() supporting the full range of clock dividers
• Added PICO_USE_FASTEST_SUPPORTED_CLOCK and PLL configuration for 200Mhz on RP2040

hardware_flash

• Move internal flash helper function to run from RAM instead of flash, so it was supported in builds other than COPY_TO_RAM

hardware_irq

• Added significantly improved documentation around IRQ handlers when using both cores
• Added enable_interrupts() and disable_interrupts() methods for when you don't care about saving or restoring the current interrupt state
• Added irq_has_handler() method to tell if a handler is installed for a particular IRQ number

hardware_pio

• Fixed support for WAIT gpio with GPIO number >= 32

pico_aon_timer

• Added a 2 RTC-clock propagation delay at the end of aon_timer_set_time_calendar() on RP2040, such that reading back the time immediately afterwards will return the right value

pico_bootrom

• Added rom_data_lookup_inline() to complement rom_data_lookup()

pico_btstack

• Updated BTStack to 1.6.2 from 1.6.1
• Updated Raspberry Pi BTStack license to cover Pico 2 W, Pico 2 WH, and RM2

pico_cyw43_driver

• Updated cyw43_driver to revision c1075d4b
• Fixed rare issue when loading firmware

pico_double

• Major cleanup, with much improved documentation
• Implemented the full complement of double conversion functions defined in pico/double.h across both RP2040 and RP2350 variants of pico_double_pico

pico_float

• Major cleanup, with much improved documentation
• RP2350 pico_float_pico_dcp variant now enables -msoft-float, since if you've chosen to use DCP instead of VFP for single-precision floating-point, you probably don't want the compiler emitting inline VFP instructions either
• Implemented the full complement of float conversion functions defined in pico/float.h across RP2040 and all RP2350 variants of pico_float_pico

pico_flash

• Fixed a build error when using FreeRTOS with configSUPPORT_DYNAMIC_ALLOCATION=0

pico_lwip

• Fixed build with PPP_SUPPORT=1 when using pico_lwip_nosys

pico_mbedtls

• Added correct cleanup of RP2350 SHA256 state during mbedtls_sha256_free()

pico_multicore

• Added multicore_lockout_victim_deinit()
• multicore_reset_core1() now marks Core 1 as de-initialized w.r.t. multicore_lockout_victim_ functions, allowing multicore_lockout_victim_init() to perform correctly after the reset

pico_runtime_init

• Added SYS_CLK_VREG_VOLTAGE_AUTO_ADJUST to indicate the voltage regular should be set to SYS_CLK_VREG_VOLTAGE_MIN during default clock setup in order to support the configured system clock frequency

pico_sha256

• Added pico_sha256_cleanup() to clean up from an in-progress SHA256 operation which was not completed via pico_sha256_finish()

pico_stdio_usb

• Allow user to override CFG_TUD_CDC_RX_BUFSIZE,
  CFG_TUD_CDC_TX_BUFSIZE and CFG_TUD_CDC_EP_BUFSIZE defines to increase performance

pico_time

• Fixed a rare race condition that could cause alarms/repeating timers to get "lost"

TinyUSB

• Updated TinyUSB to 0.18.0 from 0.17.0

FreeRTOS

• FreeRTOS support for RP2350 (Arm/RISC-V) has been upstreamed to https://github.com/FreeRTOS/FreeRTOS-Kernel, however is not yet in any official release, so you should use the latest from the main branch there and make sure you initialize the submodules as RP2350 support is actually in a submodule
• If your project embeds FreeRTOS_Kernel_import.cmake, you should update to the latest version here which works for both RP2040 and RP2350

Pioasm

• Fixed encoding of WAIT GPIO with GPIO number >= 32
• Python output now correctly emits word(x) for all PIO version 1 (RP2350) PIO instructions

SVD

• Fixed access type for DMA CHAN_ABORT register to be read-write (with clear-on-write) for both RP2040 and RP2350

Build

• GCC 14 is now supported
• LLVM Embedded Toolchain For Arm 19.x is now supported
• Multiple .pio files now supported in pico_generate_pio_header()
• .DIS files for builds using LLVM/Clang on RP2350 now contain correct disassembly for VFP floating point instructions
• Fixed some newer CMake version deprecation warnings
• Added explicit license to pico_sdk_import.cmake as it is copied into external projects

Bazel Build

• Updated LLVM/Clang toolchain to fix stack overflow issue with fma() related math functions

New Examples

These are in the pico_examples repository.

Added in 2.1.0 timeframe

These examples were added in the 2.1.0 timeframe but were not listed in the release notes then:

Example	Description
binary_info/blink_any	Uses bi_ptr variables to create a configurable blink binary - see the separate readme for mote details
binary_info/hello_anything	Uses bi_ptr variables to create a configurable hello_world binary - see the separate readme for more details
i2c/slave_mem_i2c_burst	i2c slave example where the slave implements a 256 byte memory. This version inefficiently writes each byte in a separate call to demonstrate read and write burst mode.
pico_w/wifi/picow_blink_slow_clock	Blinks the on-board LED (which is connected via the WiFi chip) with a slower system clock to show how to reconfigure communication with the WiFi chip at run time under those circumstances
pico_w/wifi/picow_blink_fast_clock	Blinks the on-board LED (which is connected via the WiFi chip) with a faster system clock to show how to reconfigure communication with the WiFi chip at build time under those circumstances
pico_w/wifi/picow_http_client	Demonstrates how to make http and https requests
...

2.1.0

This is a minor release of the SDK with many bug fixes and documentation improvements, along with some new features.

Highlights are listed below, or you can see the full list of individual commits here, and the full list of resolved issues here.

Board Support

The following board has been added and may be specified via PICO_BOARD:

• adafruit_feather_rp2350
• datanoisetv_rp2350_dsp
• hellbender_0001
• machdyne_werkzeug
• pico2_w
• pimoroni_pico_plus2_w_rp2350
• sparkfun_thingplus_rp2350

The following board configurations have been modified:

• pimoroni_plasma2350 - corrected flash size, renamed SPICE to SPCE
• pimoroni_tiny2350 - corrected flash size

Notable Library Changes/Improvements

Clock dividers in general

• A variety of methods which set clock dividers using an integer part and a fractional part, which might have been hardware_xxx_set_clkdiv_int_frac(uint16_t div_int, uint8_t div_frac) have been modified to hardware_xx_set_clkdiv_int_frac8(uint32_t div_int, uint8_t div_frac). This has been done for consistency and to make the APIs more resistant to hardware changes. The old APIs are preserved for backwards compatibility.
• Previously, when converting from floating-point clock divider values to the fixed point use by the hardware, the floating-point value was rounded down. The new default (as configured by PICO_CLKDIV_ROUND_NEAREST) is to round to the nearest achievable value. This minor change in behavior was deemed better in general, which is why the default was changed. You may set PICO_CLKDIV_ROUND_NEAREST=0 to restore the previous beahvior by default (note that individual libraries have their own configuration values which can be used to change the behavior on a per-library basis).

cmsis

• Fixed exception renaming for RP2350

hardware_adc

• Added PICO_ADC_CLKDIV_ROUND_NEAREST for controlling rounding of floating-point clock dividers

hardware_clocks

• Corrected spelling of PICO_CLOCK_AJDUST_PERI_CLOCK_WITH_SYS_CLOCK to PICO_CLOCK_ADJUST_PERI_CLOCK_WITH_SYS_CLOCK. The former is still supported.
• vco_calc.py now outputs SYS_CLK_HZ in the CMake output, which is required for clock_get_hz(clk_sys) to return the correct value
• Renamed clock_gpio_init_int_frac() to clock_gpio_init_int_frac8() to be clear that it takes an 8-bit fraction; the old name is still supported.
• Added clock_gpio_init_int_frac16() to specify the fraction with 16-bit precision (RP2350 has 16 bits of precision). This method can still be called on RP2040 in which case the low 8-bits are ignored.
• Added PICO_CLOCK_GPIO_CLKDIV_ROUND_NEAREST for controlling rounding of floating-point clock dividers

hardware_dma

• Fixed dma_channel_cleanup() to disable the channel with the new DMA IRQs added in RP2350

hardware_exception

• Added missing Cortex-M33 exception numbers

hardware_flash

• Prevented flash functions flash_range_eraae(), flash_range_program() and flash_do_cmd() from trashing the user's CS1 QMI configuration on RP2350
• Fixed issue with flash_safe_execute on FreeRTOS SMP

hardware_i2c

• Added i2c_write_burst_blocking and i2c_read_burst_blocking to send/receive multiple bytes without intervening stops.
• Fixed rare hang during i2c_read_blocking

hardware_interp

• Renamed interp_add_accumulater() to interp_add_accumulator(). The old incorrect spelling is still supported.

hardware_pio

• Added pio_sm_set_pins64(), pio_sm_set_pins_with_mask64() and pio_sm_set_pindirs_with_mask64() to allow setting of >32 pins.
• Much improved documentation of how GPIO numbers > 32 are handled.
• Fixed a bug in the use of a "jmp pin" > 32.
• Fixed implementation of sm_config_set_in_pin_count()
• Renamed sm_config_set_clkdiv_int_frac() to sm_config_set_clkdiv_int_frac8() to be clear that it takes an 8-bit fraction; the old name is still supported. Note that "int" part in the new method is 32-bit not 16-bit for consistency with other clkdiv methods.
• Renamed pio_calculate_clkdiv_from_float() to pio_calculate_clkdiv8_from_float() to be clear that it produces an 8-bit fraction; the old name is still supported. Note that "int" part in the new method is 32-bit not 16-bit for consistency with other clkdiv methods.
• Added PICO_PIO_CLKDIV_ROUND_NEAREST for controlling rounding of floating-point clock dividers

hardware_pwm

• Renamed pwm_config_set_clkdiv_int_frac() to pwm_config_set_clkdiv_int_frac4() to be clear that it takes an 4-bit fraction; the old name is still supported. Note that "int" part in the new method is 32-bit not 8-bit for consistency with other clkdiv methods.
• Added PICO_PWM_CLKDIV_ROUND_NEAREST for controlling rounding of floating-point clock dividers

hardware_timer

• Fixed bug with alarms when using RP2350's new TIMER1
• Corrected signature of hardware_alarm_get_irq_num() method added in SDK2.0.0. The variant that takes (and uses) a timer instance is called timer_hardware_alarm_get_irq_num().

pico_aon_timer

• Added aon_timer_start_calendar(), aon_timer_set_time_calendar(), aon_timer_get_time_calendar() and aon_timer_enable_alarm_calendar() methods. These are equivalent to the non-_calendar() variants except they deal in calendar (date/) time, rather than time intervals.

  These new variants are preferred on RP2040 since otherwise a date/time conversion must be performed which pulls in a lot of C library code. For the same reason, the pre-existing variants are preferred on RP2350. This discrepancy results from the different hardware used for the AON timer on RP2040 and RP2350.

pico_atomic

• Fixed atomic use between core 0 and core 1

pico_async_context

• Fixed possible HardFault in execute_sync() on FreeRTOS

pico_binary_info

• bi_Xpins_with_names() macros now work correctly when pin numbers are not in order

pico_bootrom

• Added rom_reset_usb_boot_extra() which supports an "activity" GPIO pin > 32 and GPIO pin inversion (active low).
• Bootrom methods that may write to flash are now protected with flash_safe_execute(). This affects rom_flash_op() and rom_explicit_buy()`

pico_bootsel_via_double_reset

• Fixed implementation on RP2350. Note the RP2350 bootrom also provides this support if enabled via OTP, however this library can be used when that is not enabled.

pico_crt0

• __HeapLimit is now correctly set by the default linker scripts again
• Fixed linker option -Wl,--print-memory-usage showing 100% RAM used

pico_clib_interface

• Made Some small improvements to picolibc integration

pico_cyw43_driver

• Allow user configuration of Wi-Fi pins (including pin numbers >32) and SPI clock, including dynamic SPI clock configuration at runtime.
• Updated cye43_driver to revision cf924bb
• Renamed cyw43_set_pio_clkdiv_int_frac() to cyw43_set_pio_clkdiv_int_frac8() to be clear that it takes an 8-bit fraction; the old name is still supported. Note that "int" part in the new method is 32-bit not 16-bit for consistency with other clkdiv methods
• Renamed CYW43_PIO_CLOCK_DIV_FRAC8 to CYW43_PIO_CLOCK_DIV_FRAC. The old name is still supported
• RISC-V is now supported
• Added PICO_BTSTACK_CYW43_MAX_HCI_PROCESS_LOOP_COUNT configuration option, which can be used to prevent starvation in high frequency Bluetooth scenarios.

pico_flash

• Support serial flash with >8 byte unique id, using the last 8 bytes rather than the first

pico_float

• Added optimized add/sub/mul implemtations for Hazard3 for better floating point speed

pico_malloc

• Fixed deadlock in calloc() and realloc() with picolibc

pico_platform

• Added pico_default_asm_volatile_goto()

pico_standard_binary_info

• Added back boot_stage2 binary info (missing in SDK 2.0.0)

pico_stdio_uart

• Fixed stdio_flush() when used with stdio_uart_init_full()
• Fixed race condition in stdio_set_chars_available_callback()

pico_stdio_usb

• Fixed Windows issue with the device not showing up if the reset interface is disabled
• Added support for resetting to USB boot with an activity LED pin > 32 or with the LED active low (on RP2350)
• Added PICO_STDIO_USB_RESET_BOOTSEL_FIXED_ACTIVITY_LED_ACTIVE_LOW setting for RP2350

pico_time

• Fixed race condition which could cause alarms to be lost
• Fixed continuous wakeup in best_effort_wfe_or_timeout() on RP2350

pico_util

• Added datetime_to_tm() and tm_to_datetime() for converting C library date/times to/from RP2040 RTC date/times
• Added pico_localtime_r() and pico_mktime() for use by pico_util time conversion code. These methods cass the equivalent C library function, but are defined weakly so the user can provide their own

TinyUSB

• Updated TinyUSB to 0.17.0

New Libraries

boot_bootrom_headers

Split out the headers defining the bootrom interface - that might be used outside the SDK - from pico_bootrom which is focused on calling the bootrom from the SDK, and has non-trivial dependencies.

hardware_xip_cache

Provides XIP cache maintenance APIs:

• RP2040 support for cache invalidation
• RP2350 support for cache invalidation/cleaning/pinning

Miscellaneous

• Numerous documentation corrections/improvements
• Various build warnings fixed in exotic compiler configuratons
• RP2350 A0/A1 silicon are no longer supported

Pioasm

• Fixed disassembly of mov rx_fifo, ... and mov ..., rx_fifo instructions

Build...

SDK 2.0.0

This is a major release which adds support for the new RP2350 and for compiling RISC-V code in addition to Arm.

• There is a lot of new functionality in the RP2350 microcontroller, it is recommended that you read the RP2350 Datasheet
• There is a lot of new functionality in the SDK, it is also worth reading the Raspberry Pi Pico C/C++ SDK book. This also includes documentation for RP2040 and RP2350 APIs, along with much more complete documentation of SDK #defines and CMake build variables.

Notices

• You should delete/recreate all build directories when upgrading from previous versions of the Raspberry Pi Pico SDK

Major New Features

Support for RP2350

Many programs you have written for RP2040 (say a Raspberry Pi Pico) should work unmodified on RP2350 (say a Raspberry Pi Pico 2) even when compiled for RISC-V.

• You can now specify rp2350-arm-s (Arm Secure) or rp2350-riscv (RISC-V) as well as the previous rp2040 (default) and host.
• Setting PICO_BOARD=some_board will now set PICO_PLATFORM if one is specified in some_board.h since most boards either use exclusively RP2040 or RP2350.
• PICO_PLATFORM also supports rp2350 but this gets replaced with the value PICO_DEFAULT_RP2350_PLATFORM which you can set in your environment or CMakeLists.txt. Many of the boards for RP2350 - including pico2- select rp2350 as the PICO_BOARD to honour your preference.
• NOTE: This release of the SDK does not support writing Arm Non-Secure binaries to run under the wing of an Arm Secure binary. This support will be added in a subsequent release.

Security and Code Signing

• The RP2350 bootrom contains support for signed images and a variety of other security features. The SDK supports building signed images etc. as part of the CMake build. For further information, please read RP2350 Datasheet "Bootrom Concepts" section, and also the Raspberry Pi Pico C/C++ SDK book for details on configuring your build to sign code. Note that signed code is only applicable to chips that have been locked down for security, but you can also hash your image for integrity checking.

Board Support

The following boards have been added and may be specified via PICO_BOARD:

• defcon32_badge
• gen4_rp2350_24
• gen4_rp2350_24ct
• gen4_rp2350_24t
• gen4_rp2350_28
• gen4_rp2350_28ct
• gen4_rp2350_28t
• gen4_rp2350_32
• gen4_rp2350_32ct
• gen4_rp2350_32t
• gen4_rp2350_35
• gen4_rp2350_35ct
• gen4_rp2350_35t
• hellbender_2350A_devboard
• ilabs_challenger_rp2350_bconnect
• ilabs_challenger_rp2350_wifi_ble
• melopero_perpetuo_rp2350_lora
• phyx_rick_tny_rp2350
• pico2
• pimoroni_pga2350
• pimoroni_pico_plus2_rp2350
• pimoroni_plasma2350
• pimoroni_tiny2350
• seeed_xiao_rp2350
• solderparty_rp2350_stamp
• solderparty_rp2350_stamp_xl
• sparkfun_promicro_rp2350
• switchscience_picossci2_conta_base
• switchscience_picossci2_dev_board
• switchscience_picossci2_micro
• switchscience_picossci2_rp2350_breakout
• switchscience_picossci2_tiny
• tinycircuits_thumby_color_rp2350

New Libraries

hardware_boot_lock (RP2350)

• New library for accessing the BOOT locks from secure code.

hardware_dcp (RP2350 Arm)

• Contains assembler macros for individual DCP (Double Co-Processor) instructions
• Contains assembler macros for canned instruction sequences for higher-level operations
• HAS_DOUBLE_COPROCESSOR define indicates hardware support

hardware_hazard3 (RP2350 RISC-V)

• Assembler macros and inline functions for accessing Hazard3 extensions

hardware_powman (RP2350)

• Hardware APIs for the Power Management hardware.
• HAS_POWMAN_TIMER define indicates hardware support.

hardware_rcp (RP2350 Arm)

• Contains inline functions and assembler macros for the RCP (Redundancy Co-Processor) instructions.
• HAS_REDUNDANCY_COPROCESSOR define indicates hardware support.

hardware_riscv_platform_timer (RP2350)

• Hardware APIs for the RISC-V Platform Timer (which is also made available on Arm).

hardware_sha256 (RP2350)

• Hardware APIs for the SHA256 hashing hardware.

hardware_ticks

• Hardware APIs for the RP2350 tick generators.
• On RP2040 the same API is used, but only one tick generator TICK_WATCHDOG is used, which is backed by the hardware in the RP2040 WatchDog hardware.

pico_aon_timer

• Abstraction for a hardware timer that is "Always-On", and can wake the processor up even from a low power state at a given time.
• On RP2040 this uses the RTC.
• On RP2350 this uses the Powman Timer.

pico_atomic

• Additional support for C11 atomic functions using spin lock number PICO_SPINLOCK_ID_ATOMIC.
• On RP2040, all functions are implemented via spinlock.
• On RP2350, only 64-bit or arbitrary-sized atomics are implemented via spin lock; the reset user processor exclusive/atomic instructions.
  • Note on ACTLR.EXTEXCLALL must be set to 1 on each processor for the exclusive instructions to work. This is done automatically in the SDK by one of the per-core initializers in pico_runtime_init.
• Included by pico_runtime by default.

pico_boot_lock (RP2350)

• Support for acquiring and releasing locks to prevent concurrent use of hardware resources used by bootrom functions.
• Enabled via PICO_BOOTROM_LOCKING_ENABLED which defaults to 1 on RP2350.
• Some bootrom functions use shared resources such as the single SHA256 or put hardware such as the OTP or XIP interface into a state that cannot execute concurrently with certain other code. The bootrom supports checking that the resource is owned, and this library turns that checking on.
• The bootrom function wrappers in pico_bootrom call the functions in pico_boot_lock around affects bootrom functions, and thus will take and release locks if PICO_BOOTROM_LOCKING_ENABLED=1.
• NUM_BOOT_LOCKS define indicates the number of boot locks (8 on 'RP2350', 0 on 'RP2040').

pico_clib_interface

• New library to encapsulate the interface between the SDK and the C library.
• Supports
• newlib (full).
• picolibc (preview).
• llvm-libc(preview).
• Included by pico_runtime by default.

pico_crt0

• New library split out of pico_standard_link to encapsulate the earliest startup code before the runtime initialisation, and shutdown code after the runtime.
• Repository for the default RP2040 and RP2350 linker scripts.
• The flash size specified in the board header is now used when linking which is handy if you have >2M of flash and >2M of code/data.
• Note: The linker scripts have changed since the previous release of the SDK. If you have custom linker scripts, it is recommended that you update them to match.
  • In particular the new linker scripts include an "embedded block" which is required for a binary to boot on RP2350.
  • __HeapLimit is now defined to be the end of RAM rather than the end of a PICO_HEAP_SIZE chunk, to better match the standard behaviour. PICO_HEAP_SIZE is the minimum heap size required, and space is required for it at link time. sbrk in the previous SDK ignored it anyway and used the end of RAM so there is no functional change there.
• Included by pico_runtime by default

pico_cxx_options

• New library split out of pico_standard_link to configure C++ options.
• Included by pico_standard_link by default.

pico_platform_compiler

• New library split out of pico_platform with the functions/macros related to the compiler.
• Included by pico_platform by default.

pico_platform_panic

• New library split out of pico_platform with the panic function implementation.
• Included by pico_platform by default.

pico_platform_sections

• New library split out of pico_platform with the section macros such as __not_in_flash_func.
• Included by pico_platform by default.

pico_runtime_init

• Contains the standard initialisers that should get run before main, or per core.
• Unlike in the previous SDK version where runtime_init() was a monolithic function which also called some __preinit_array initialisers, the new runtime_init library:
• Separates each initialiser out individually, for say initialiser "foo".
  • Defines PICO_RUNTIME_INIT_FOO which is a "12345" line number ordering of the initialiser with respect to others.
  • Declares runtime_init_foo() which is the actual initialiser.
  • If PICO_RUNTIME_SKIP_INIT_FOO is not set, it adds the initialiser entry to call runtime_init_foo() before main (or per core initialisation).
  • If PICO_RUNTIME_NO_INIT_FOO is not set, it adds the (weak) implementation of runtime_init_foo().
• This gives the user full control to customise runtime initialisation, either skipping or replacing parts.
• Included by pico_runtime by default.

pico_sha256

• High level APIs for generating SHA256 hashes both synchronously and asynchronously

pico_standard_binary_info

• New library split out of pico_standard_link that adds the "common" binary info items to the binary.
• Included by pico_standard_link by default.

Library Changes / Improvements

Note that all hardware libraries now support the increased number of GPIOs on RP2350B in APIs that take a GPIO number; this is not noted for every library.

pico_base

• More error return codes were added to pico/error.h, mostly because these are the same values returned by RP2350 bootrom API functions, but also a number of new SDK APIs also return meaningful errors.
• In pico/types.h, by popular demand, absolute_time_t now always defaults to uint64_t regardless of the type of build. You can set `PICO_OPAQUE_ABSOLUTE_TIME_...

SDK 1.5.1

This release is largely a bug fix release, however it also makes Bluetooth support official and adds some new libraries and functionality.

Highlights are listed below, or you can see the full list of individual commits here, and the full list of resolved issues here.

Board Support

The following board has been added and may be specified via PICO_BOARD:

• pololu_3pi_2040_robot

The following board configurations have been modified:

• adafruit_itsybitsy_rp2040 - corrected the mismatched PICO_DEFAULT_I2C bus number (favors the breadboard pins not the stemma connector).
• sparkfun_thingplus - added WS2812 pin config.

Library Changes/Improvements

hardware_dma

• Added dma_channel_cleanup() function that can be used to clean up a dynamically claimed DMA channel after use, such that it won't be in a surprising state for the next user, making sure that any in-flight transfer is aborted, and no interrupts are left pending.

hardware_spi

• The spi_set_format, spi_set_slave, spi_set_baudrate functions that modify the configuration of an SPI instance, now disable the SPI while changing the configuration as specified in the data sheet.

pico_async_context

• Added user_data member to async_when_pending_worker_t to match async_at_time_worker_t.

pico_cyw43_arch

• Added cyw43_arch_disable_sta_mode() function to complement cyw43_arch_enable_sta_mode().
• Added cyw43_arch_disable_ap_mode() function to complement cyw43_arch_enable_ap_mode().

pico_stdio_usb

• The 20-character limit for descriptor strings USBD_PRODUCT and USBD_MANUFACTURER can now be extended by defining
  USBD_DESC_STR_MAX.
• PICO_STDIO_USB_CONNECT_WAIT_TIMEOUT_MS is now supported in the build as well as compiler definitions; if it is set in the build, it is added to the compile definitions.

pico_rand

• Fixed poor randomness when PICO_RAND_ENTROPY_SRC_BUS_PERF_COUNTER=1.

PLL and Clocks

• The set_sys_clock_pll and set_sys_clock_khz methods now reference a pre-processor define PICO_CLOCK_AJDUST_PERI_CLOCK_WITH_SYS_CLOCK. If set to 1, the peripheral clock is updated to match the new system clock, otherwise the preexisting behavior (of setting the peripheral clock to a safe 48Mhz) is preserved.
• Support for non-standard crystal frequencies, and compile-time custom clock configurations:
  • The new define XOSC_KHZ is used in preference to the preexisting XOSC_MHZ to define the crystal oscillator frequency. This value is now also correctly plumbed through the various clock setup functions, such that they behave correctly with a crystal frequency other than 12Mhz. XOSC_MHZ will be automatically defined for backwards compatibility if XOSC_KHZ is an exact multiple of 1000 Khz. Note that either XOSC_MHZ or XOSC_KHZ may be specified by the user, but not both.
  • The new define PLL_COMMON_REFDIV can be specified to override the default reference divider of 1.
  • The new defines PLL_SYS_VCO_FREQ_KHZ, PLL_SYS_POSTDIV1 and PLL_SYS_POSTDIV2 are used to configure the system clock PLL during runtime initialization. These are defaulted for you if SYS_CLK_KHZ=125000, XOSC_KHZ=12000 and PLL_COMMON_REFDIV=1. You can modify these values in your CMakeLists.txt if you want to configure a different system clock during runtime initialization, or are using a non-standard crystal.
  • The new defines PLL_USB_VCO_FREQ_KHZ, PLL_USB_POSTDIV1 and PLL_USB_POSTDIV2 are used to configure the USB clock PLL during runtime initialization. These are defaulted for you if USB_CLK_KHZ=48000, XOSC_KHZ=12000 and PLL_COMMON_REFDIV=1. You can modify these values in your CMakeLists.txt if you want to configure a different USB clock if you are using a non-standard crystal.
  • The new define PICO_PLL_VCO_MIN_FREQ_KHZ is used in preference to the pre-existing PICO_PLL_VCO_MIN_FREQ_MHZ, though specifying either is supported.
  • The new define PICO_PLL_VCO_MAX_FREQ_KHZ is used in preference to the pre-existing PICO_PLL_VCO_MAX_FREQ_MHZ, though specifying either is supported.

New Libraries

pico_flash

• This is a new higher level library than hardware_flash. It provides helper functions to facilitate getting into a
  state where it is safe to write to flash (the default implementation disables interrupts on the current core, and if
  necessary, makes sure the other core is running from RAM, and has interrupts disabled).
• Adds a flash_safe_execute() function to execute a callback function while in the "safe" state.
• Adds a flash_safe_execute_core_init() function which must be called from the "other core" when using pico_multicore to enable the cooperative support for entering a "safe" state.
• Supports user override of the mechanism by overriding the get_flash_safety_helper() function.

Miscellaneous

• All assembly (including inline) in the SDK now uses the unified syntax.
  • New C macros pico_default_asm( ... ) and pico_default_asm_volatile( ... ) are provided that are equivalent to __asm and __asm volatile blocks, but with a .syntax unified at the beginning.
• A new assembler macro pico_default_asm_setup is provided to configure the correct CPU and dialect.
• Some code cleanup to make the SDK code at least compile cleanly on Clang and IAR.

Build

• PICO_BOARD and PICO_BOARD_HEADER_DIRS now correctly use the latest environment variable value if present.

• A CMake performance regression due to repeated calls to find_package has been fixed.

• Experimental support is provided for compiling with Clang. As an example, you can build with the
  LLVM Embedded Toolchain for Arm, noting however that currently only version 14.0.0 works, as later versions use picolib rather than newlib.

  • Note that if you are using TinyUSB you need to use the latest master to compile with Clang.

  mkdir clang_build
  cd clang_build
  cmake -DPICO_COMPILER=pico_arm_clang -DPICO_TOOLCHAIN_PATH=/path/to/arm-embedded-llvm-14.0.0 ..
  make
  

Bluetooth Support for Pico W

The support is now official. Please find examples in pico-examples.

• The Bluetooth API is provided by BTstack.
• The following libraries are provided that expose core BTstack functionality:
  • pico_btstack_ble - Adds Bluetooth Low Energy (LE) support.
  • pico_btstack_classic - Adds Bluetooth Classic support.
  • pico_btstack_sbc_encoder - Adds Bluetooth Sub Band Coding (SBC) encoder support.
  • pico_btstack_sbc_decoder - Adds Bluetooth Sub Band Coding (SBC) decoder support.
  • pico_btstack_bnep_lwip - Adds Bluetooth Network Encapsulation Protocol (BNEP) support using LwIP.
  • pico_btstack_bnep_lwip_sys_freertos - Adds Bluetooth Network Encapsulation Protocol (BNEP) support using LwIP with FreeRTOS for NO_SYS=0.
• The following integration libraries are also provided:
  • pico_btstack_run_loop_async_context - provides a common async_context backed implementation of a BTstack "run loop" that can be used for all BTstack use with the pico-sdk.
  • pico_btstack_flash_bank - provides a sample implementation for storing required Bluetooth state in flash.
  • pico_btstack_cyw43 - integrates BTstack with the CYW43 driver.
• The CMake function pico_btstack_make_gatt_header can be used to run the BTstack compile_gatt tool to make a GATT header file from a BTstack GATT file.
• pico_cyw43_driver and cyw43_driver now support HCI communication for Bluetooth.
• cyw43_driver_picow now supports Pico W specific HCI communication for Bluetooth over SPI.
• cyw43_arch_init() and cyw43_arch_deinit() automatically handle Bluetooth support if CYW43_ENABLE_BLUETOOTH is 1 (as it will be automatically if you depend on pico_btstack_cyw43).

Key changes since 1.5.0:

• Added Raspberry Pi specific BTstack license.
• The storage offset in flash for pico_btstack_flash_bank can be specified at runtime by defining pico_flash_bank_get_storage_offset_func to your own function to return the offset within flash.
• pico_btstack_flash_bank is now safe for multicore / FreeRTOS SMP use, as it uses the new pico_flash library to make sure the other core is not accessing flash during flash updates. If you are using pico_multicoreyou must have called flash_safe_execute_core_init from the "other" core (to the one Bluetooth is running on).
• Automatically set Bluetooth MAC address to the correct MAC address (Wi-Fi MAC address + 1), as some devices do not have it set in OTP and were using the same default MAC from the Bluetooth chip causing collisions.
• Various bug-fixes and stability improvements (especially with concurrent Wi-Fi), including updating cyw43_driver and btstack to the newest versions.

Authors

Thanks to the following for their contributions:

2bndy5,
agento2,
Andrew Burge,
Andrew Scheller,
arjunak234,
David Thacher,
djazz,
Graham Sanderson,
hubiscode,
James Hughes,
Luke Wren,
Malte Thiesen,
Michael Busby,
Mr. Green's Workshop,
Paul Grayson,
Peter Harper

SDK 1.5.0

This release contains new libraries and functionality, along with numerous bug fixes and documentation improvements.

Highlights are listed below, or you can see the full list of individual commits here, and the full list of resolved issues here.

Note, these release notes are long and may appear truncated in the "Releases" tab; you can see the full version here.

New Board Support

The following boards have been added and may be specified via PICO_BOARD:

• nullbits_bit_c_pro
• waveshare_rp2040_lcd_1.28
• waveshare_rp2040_one

Library Changes/Improvements

hardware_clocks

• clock_gpio_init() now takes a float for the clock divider value, rather than an int.
• Added clock_gpio_init_int_frac() function to allow initialization of integer and fractional part of the clock divider value, without using float.
• Added --ref-min option to vcocalc.py to override the minimum reference frequency allowed.
• vcocalc.py now additionally considers reference frequency dividers greater than 1.

hardware_divider

• Improved the performance of hw_divider_ functions.

hardware_dma

• Added dma_sniffer_set_output_invert_enabled() and dma_sniffer_set_output_reverse_enabled() functions to configure the DMA sniffer.
• Added dma_sniffer_set_data_accumulator() and dma_sniffer_get_data_accumulator() functions to access the DMA sniffer accumulator.

hardware_i2c

• Added i2c_get_instance() function for consistency with other hardware_ libraries.
• Added i2c_read_byte_raw(), i2c_write_byte_raw() functions to directly read and write the I2C data register for an I2C instance.

hardware_timer

• Added hardware_alarm_claim_unused() function to claim an unused hardware timer.

pico_cyw43_arch

• Added cyw43_arch_wifi_connect_bssid_ variants of cyw43_arch_wifi_connect_ functions to allow connection to a specific access point.
• Blocking cyw43_arch_wifi_connect_ functions now continue trying to connect rather than failing immediately if the network is not found.
• cyw43_arch_wifi_connect_ functions now return consistent return codes (PICO_OK, or PICO_ERROR_XXX).
• The pico_cyw43_arch library has been completely rewritten on top of the new pico_async_context library that generically abstracts the different types of asynchronous operation (poll, threadsafe_background and freertos) previously handled in a bespoke fashion by pico_cyw43_arch. Many edge case bugs have been fixed as a result of this. Note that this change should be entirely backwards compatible from the user point of view.
• cyw43_arch_init() and cyw43_arch_deinit() functions are now very thin layers which handle async_context life-cycles, along with adding support for the cyw43_driver, lwIP, BTstack etc. to that async_context. Currently, these mechanisms remain the preferred documented way to initialize Pico W networking, however you are free to do similar initialization/de-initialization yourself.
• Added cyw43_arch_set_async_context() function to specify a custom async_context prior to calling cyw43_arch_init*()
• Added cyw43_arch_async_context() function to get the async_context used by the CYW43 architecture support.
• Added cyw43_arch_init_default_async_context() function to return the async_context that cyw43_arch_init*() would initialize if one has not been set by the user.
• Added cyw43_arch_wait_for_work_until() function to block until there is networking work to be done. This is most useful for poll style applications that have no other work to do and wish to sleep until cyw43_arch_poll() needs to be called again.

pico_cyw43_driver

• The functionality has been clarified into 3 separate libraries:
  • cyw43_driver - the raw cyw43_driver code.
  • cyw43_driver_picow - additional support for communication with the Wi-Fi chip over SPI on Pico W.
  • pico_cyw43_driver - integration of the cyw43_driver with the pico-sdk via async_context
• Added CYW43_WIFI_NVRAM_INCLUDE_FILE define to allow user to override the NVRAM file.

pico_divider

• Improved the performance of 64-bit divider functions.

pico_platform

• Add panic_compact() function that discards the message to save space in non-debug (NEBUG defined) builds.

pico_runtime

• Added proper implementation of certain missing newlib system APIs: _gettimeofday(), _times(), _isatty(), _getpid().
• The above changes enable certain additional C/C++ library functionality such as gettimeofday(), times() and std::chrono.
• Added settimeofday() implementation such that gettimeofday() can be meaningfully used.
• Added default (return -1) implementations of the remaining newlib system APIs: _open(), _close(), _lseek(), _fstat(), _isatty(), _kill(), to prevent warnings on GCC 12.
• Made all newlib system API implementations weak so the user can override them.

pico_stdio

• pico_stdio allows for outputting from within an IRQ handler that creates the potential for deadlocks (especially with pico_stdio_usb), and the intention is to not deadlock but instead discard output in any cases where a deadlock would otherwise occur. The code has been revamped to avoid more deadlock cases, and a new define PICO_STDIO_DEADLOCK_TIMEOUT_MS has been added to catch remaining cases that might be caused by user level locking.
• Added stdio_set_chars_available_callback() function to set a callback to be called when input is available. See also the new PICO_STDIO_USB_SUPPORT_CHARS_AVAILABLE_CALLBACK and PICO_STDIO_UART_SUPPORT_CHARS_AVAILABLE_CALLBACK defines which both default to 1 and control the availability of this new feature for USB and UART stdio respectively (at the cost of a little more code).
• Improved performance of stdio_semihosting.
• Give the user more control over the USB descriptors of stdio_usb via USBD_VID, USBD_PID, USBD_PRODUCT, PICO_STDIO_USB_CONNECTION_WITHOUT_DTR and PICO_STDIO_USB_DEVICE_SELF_POWERED

pico_sync

• Added critical_section_is_initialized() function to test if a critical section has been initialized.
• Added mutex_try_enter_block_until() function to wait only up to a certain time to acquire a mutex.

pico_time

• Added from_us_since_boot() function to convert a uint64_t timestamp to an absolute_time_t.
• Added absolute_time_min() function to return the earlier of two absolute_time_t values.
• Added alarm_pool_create_with_unused_hardware_alarm() function to create an alarm pool using a hardware alarm number claimed using hardware_alarm_claim().
• Added alarm_pool_core_num() function to determine what core an alarm pool runs on.
• Added alarm_pool_add_alarm_at_force_in_context() function to add an alarm, and have it always run in the IRQ context even if the target time is in the past, or during the call. This may be simpler in some cases than dealing with the fire_if_past parameters to existing functions, and avoids some callbacks happening from non IRQ context.

pico_lwip

• Added pico_lwip_mqtt library to expose the MQTT app functionality in lwIP.
• Added pico_lwip_mdns library to expose the MDNS app functionality in lwIP.
• Added pico_lwip_freertos library for NO_SYS=0 with FreeRTOS as a complement to pico_lwip_nosys for NO_SYS=1.

TinyUSB

• TinyUSB has upgraded from 0.12.0 to 0.15.0. See TinyUSB release notes here for details.
• Particularly host support should be massively improved.
• Defaulted new TinyUSB dcd_rp2040 driver's TUD_OPT_RP2040_USB_DEVICE_UFRAME_FIX variable to 1 as a workaround for errata RP2040-E15. This fix is required for correctness, but comes at the cost of some performance, so applications that won't ever be plugged into a Pi 4 or Pi 400 can optionally disable this by setting the value of TUD_OPT_RP2040_USB_DEVICE_UFRAME_FIXto 0 either via target_compile_definitions in their CMakeLists.txt or in their tusb_config.h.

New Libraries

pico_async_context

• Provides support for asynchronous events (timers/IRQ notifications) to be handled in a safe context without concurrent execution (as required by many asynchronous 3rd party libraries).
• Provides implementations matching those previously implemented in pico_cyw43_arch:
  • poll - Not thread-safe; the user must call async_context_poll() periodically from their main loop, but can call async_context_wait_for_work_until() to block until work is required.
  • threadsafe_background - No polling is required; instead asynchronous work is performed in a low priority IRQ. Locking is provided such that IRQ/non-IRQ or multiple cores can interact safely.
  • freertos - Asynchronous work is performed in a separate FreeRTOS task.
• async_context guarantees all callbacks happen on a single core.
• async_context supports multiple instances for providing independent context which can execute concurrently with respect to each other.

pico_i2c_slave

• A (slightly modified) pico_i2c_slave library from https://github.com/vmilea/pico_i2c_slave
• Adds a callback style event API for handling I2C slave requests.

pico_mbedtls

• Added pico_mbedtls library to provide MBed TLS support. You can depend on both pico_lwip_mbedtls and pico_mbedtls to use MBed TLS and lwIP together. See the tls_client example in pico-examples for more details.

pico_rand

• Implements a new Random Number Generator API.
• pico_rand generates rando...

SDK version 1.4.0

This release adds wireless support for the Raspberry Pi Pico W, adds support for other new boards, and contains various
bug fixes, documentation improvements, and minor improvements/added functionality. You can see the full list of individual commits here.

New Board Support

The following boards have been added and may be specified via PICO_BOARD:

• pico_w
• datanoisetv_rp2040_dsp
• solderparty_rp2040_stamp_round_carrier

Wireless Support

• Support for the Raspberry Pi Pico W is now included with the SDK (PICO_BOARD=pico_w). The Pico W uses a driver
  for the wireless chip called cyw43_driver which is included as a submodule of the SDK. You need to initialize
  this submodule for Pico W wireless support to be available. Note that the LED on the Pico W board is only
  accessible via the wireless chip and can be accessed via cyw43_arch_gpio_put() and
  cyw43_arch_gpio_get() (part of the pico_cyw43_arch library described below). As a result of the LED being on
  the wireless chip, there is no PICO_DEFAULT_LED_PIN setting and the default LED based examples in pico-examples
  do not work with the Pico W.

• IP support is provided by lwIP which is also included as a
  submodule which you should initialize if you want to use it.

  The following libraries exposing lwIP functionality are provided by the SDK:

  • pico_lwip_core (included in pico_lwip)
  • pico_lwip_core4 (included in pico_lwip)
  • pico_lwip_core6 (included in pico_lwip)
  • pico_lwip_netif (included in pico_lwip)
  • pico_lwip_sixlowpan (included in pico_lwip)
  • pico_lwip_ppp (included in pico_lwip)
  • pico_lwip_api (this is a blocking API that may be used with FreeRTOS and is not included in pico_lwip)

  As referenced above, the SDK provides a pico_lwip which aggregates all of the commonly needed lwIP functionality.
  You are of course free to use the substituent libraries explicitly instead.

  The following libraries are provided that contain the equivalent lwIP application support:

  • pico_lwip_snmp
  • pico_lwip_http
  • pico_lwip_makefsdata
  • pico_lwip_iperf
  • pico_lwip_smtp
  • pico_lwip_sntp
  • pico_lwip_mdns
  • pico_lwip_netbios
  • pico_lwip_tftp
  • pico_lwip_mbedtls

• Integration of the IP stack and the cyw43_driver network driver into the user's code is handled by
  pico_cyw43_arch. Both the IP stack and the driver need to do work in response to network traffic, and
  pico_cyw43_arch provides a variety of strategies for servicing that work. Four architecture variants
  are currently provided as libraries:

  • pico_cyw43_arch_lwip_poll - For using the RAW lwIP API (NO_SYS=1 mode) with polling. With this architecture
    the user code must periodically poll via cyw43_arch_poll() to perform background work. This architecture
    matches the common use of lwIP on microcontrollers, and provides no multicore safety
  • pico_cyw43_arch_lwip_threadsafe_background - For using the RAW lwIP API (NO_SYS=1 mode) with multicore
    safety, and automatic servicing of the cyw43_driver and
    lwIP in the background. User polling is not required with this architecture, but care should be taken as lwIP
    callbacks happen in an IRQ context.
  • pico_cyw43_arch_lwip_sys_freertos - For using the full lwIP API including blocking sockets in OS mode
    (NO_SYS=0), along with multicore/task safety, and automatic servicing of the cyw43_driver and the lwIP
    stack in a separate task. This powerful architecture works with both SMP and non-SMP variants of the RP2040 port
    of FreeRTOS-Kernel. Note you must set FREERTOS_KERNEL_PATH in your build to use this variant.
  • pico_cyw43_arch_none - If you do not need the TCP/IP stack but wish to use the on-board LED or other wireless
    chip connected GPIOs.

  See the library documentation or the pico/cyw43_arch.h header for more details.

Notable Library Changes/Improvements

hardware_dma

• Added dma_unclaim_mask() function for un-claiming multiple DMA channels at once.
• Added channel_config_set_high_priority() function to set the channel priority via a channel config object.

hardware_gpio

• Improved the documentation for the pre-existing gpio IRQ functions which use the "one callback per core" callback
  mechanism,
  and added a gpio_set_irq_callback() function to explicitly set the callback independently of enabling per pin GPIO
  IRQs.

• Reduced the latency of calling the existing "one callback per core" GPIO IRQ callback.

• Added new support for the user to add their own shared GPIO IRQ handler independent of the pre-existing
  "one callback per core" callback mechanism, allowing for independent usage of GPIO IRQs without having to share one
  handler.
  See
  the
  documentation in hardware/irq.h for full details of the functions added:

  • gpio_add_raw_irq_handler()
  • gpio_add_raw_irq_handler_masked()
  • gpio_add_raw_irq_handler_with_order_priority()
  • gpio_add_raw_irq_handler_with_order_priority_masked()
  • gpio_remove_raw_irq_handler()
  • gpio_remove_raw_irq_handler_masked()

• Added a gpio_get_irq_event_mask() utility function for use by the new "raw" IRQ handlers.

hardware_irq

• Added user_irq_claim(), user_irq_unclaim(), user_irq_claim_unused() and user_irq_is_claimed()
  functions for claiming ownership of the user IRQs (the ones numbered 26-31 and not connected to any hardware).
  Uses of the user IRQs have been updated to use these functions. For stdio_usb, the PICO_STDIO_USB_LOW_PRIORITY_IRQ define is still respected if specified, but otherwise an unclaimed one is
  chosen.
• Added an irq_is_shared_handler() function to determine if a particular IRQ uses a shared handler.

pico_sync

• Added a sem_try_acquire() function, for non blocking acquisition of a semaphore.

pico_stdio

• stderr is now supported and goes to the same destination as stdout.
• Zero timeouts for getchar_timeout_us() are now correctly honored (previously they were a 1us minimum).

stdio_usb

• stdio over USB can now be used even if you are linking to tinyusb_device yourself. If you have a CDC device in your device descriptors, you can use pico_enable_stdio_usb(TARGET 1) in your CMakeLists.txt
• The use of a 1ms timer to handle background TinyUSB work has been replaced with use of a more interrupt driven
  approach using a user IRQ for better performance. Note this new feature is disabled if shared IRQ handlers
  are disabled via PICO_DISABLE_SHARED_IRQ_HANDLERS=1

miscellaneous

• get_core_num() has been moved to pico/platform.h from hardware/sync.h.
• The C library function realloc() is now multicore safe too.
• The minimum PLL frequency has been increased from 400Mhz to 750Mhz to improve stability across operating
  conditions. This should not affect the majority of users in any way, but may impact those trying to set
  particularly low clock frequencies. If you do wish to return to the previous
  minimum, you can set PICO_PLL_VCO_MIN_FREQ_MHZ back to 400. There is also a new PICO_PLL_VCO_MAX_FREQ_MHZ
  which defaults to 1600.

Build

• Compilation with GCC 12 is now supported.

SDK version 1.3.1

This release contains numerous bug fixes and documentation improvements which are not all listed here; you can see the full list of individual commits here.

New Board Support

The following boards have been added and may be specified via PICO_BOARD:

• adafruit_kb2040
• adafruit_macropad_rp2040
• eetree_gamekit_rp2040
• garatronic_pybstick26_rp2040 (renamed from pybstick26_rp2040)
• pimoroni_badger2040
• pimoroni_motor2040
• pimoroni_servo2040
• pimoroni_tiny2040_2mb
• seeed_xiao_rp2040
• solderparty_rp2040_stamp_carrier
• solderparty_rp2040_stamp
• wiznet_w5100s_evb_pico

Notable Library Changes/Improvements

hardware_dma

• New documentation has been added to the dma_channel_abort() function describing errata RP2040-E13, and how to work around it.

hardware_irq

• Fixed a bug related to removing and then re-adding shared IRQ handlers. It is now possible to add/remove handlers as documented.
• Added new documentation clarifying the fact the shared IRQ handler ordering "priorities" have values that increase with higher priority vs Cortex M0+ IRQ priorites which have values that decrease with priority!

hardware_pwm

• Added a pwm_config_set_clkdiv_int_frac() method to complement pwm_config_set_clkdiv_int() and pwm_config_set_clkdiv().

hardware_pio

• Fixed the pio_set_irqn_source_mask_enabled() method which previously affected the wrong IRQ.

hardware_rtc

• Added clarification to rtc_set_datetime() documentation that the new value may not be visible to a rtc_get_datetime() very soon after, due to crossing of clock domains.

pico_platform

• Added a busy_wait_at_least_cycles() method as a convenience method for a short tight-loop counter-based delay.

pico_stdio

• Fixed a bug related to removing stdio "drivers". stdio_set_driver_eabled() can now be used freely to dynamically enable and disable drivers during runtime.

pico_time

• Added an is_at_the_end_of_time() method to check if a given time matches the SDK's maximum time value.

Runtime

• A bug in __ctzdi2() aka __builtin_ctz(uint64_t) was fixed.

Build

• Compilation with GCC 11 is now supported.
• PIOASM_EXTRA_SOURCE_FILES is now actually respected.

pioasm

• Input files with Windows (CRLF) line endings are now accepted.
• A bug in the python output was fixed.

elf2uf2

• Extra padding was added to the UF2 output of misaligned or non-contiguous binaries to work around errata RP2040-E14.

---

Note the 1.3.0 release of the SDK incorrectly squashed the history of the changes. A new merge commit has been added to restore the full history, and the 1.3.0 tag has been updated

SDK version 1.3.0

This release contains numerous bug fixes and documentation improvements. Additionally, it contains the following notable changes/improvements:

Updated TinyUSB to 0.12.0

• The lib/tinyusb submodule has been updated from 0.10.1 to 0.12.0. See https://github.com/hathach/tinyusb/releases/tag/0.11.0 and https://github.com/hathach/tinyusb/releases/tag/0.12.0 for release notes.
• Improvements have been made for projects that include TinyUSB and also compile with enhanced warning levels and -Werror. Warnings have been fixed in rp2040 specific TinyUSB code, and in TinyUSB headers, and a new cmake function suppress_tinyusb_warnings() has been added, that you may call from your CMakeLists.txt to suppress warnings in other TinyUSB C files.

New Board Support

The following boards have been added and may be specified via PICO_BOARD:

• adafruit_trinkey_qt2040
• melopero_shake_rp2040
• pimoroni_interstate75
• pimoroni_plasma2040
• pybstick26_rp2040
• waveshare_rp2040_lcd_0.96
• waveshare_rp2040_plus_4mb
• waveshare_rp2040_plus_16mb
• waveshare_rp2040_zero

Updated SVD, hardware_regs, hardware_structs

The RP2040 SVD has been updated, fixing some register access types and adding new documentation.

The hardware_regs headers have been updated accordingly.

The hardware_structs headers which were previously hand coded, are now generated from the SVD, and retain select documentation from the SVD, including register descriptions and register bit-field tables.

e.g. what was once

typedef struct {
    io_rw_32 ctrl;
    io_ro_32 fstat;
    ...

becomes:

// Reference to datasheet: https://datasheets.raspberrypi.com/rp2040/rp2040-datasheet.pdf#tab-registerlist_pio
//
// The _REG_ macro is intended to help make the register navigable in your IDE (for example, using the "Go to Definition" feature)
// _REG_(x) will link to the corresponding register in hardware/regs/pio.h.
//
// Bit-field descriptions are of the form:
// BITMASK [BITRANGE]: FIELDNAME (RESETVALUE): DESCRIPTION

typedef struct {
    _REG_(PIO_CTRL_OFFSET) // PIO_CTRL
    // PIO control register
    // 0x00000f00 [11:8]  : CLKDIV_RESTART (0): Restart a state machine's clock divider from an initial phase of 0
    // 0x000000f0 [7:4]   : SM_RESTART (0): Write 1 to instantly clear internal SM state which may be otherwise difficult...
    // 0x0000000f [3:0]   : SM_ENABLE (0): Enable/disable each of the four state machines by writing 1/0 to each of these four bits
    io_rw_32 ctrl;

    _REG_(PIO_FSTAT_OFFSET) // PIO_FSTAT
    // FIFO status register
    // 0x0f000000 [27:24] : TXEMPTY (0xf): State machine TX FIFO is empty
    // 0x000f0000 [19:16] : TXFULL (0): State machine TX FIFO is full
    // 0x00000f00 [11:8]  : RXEMPTY (0xf): State machine RX FIFO is empty
    // 0x0000000f [3:0]   : RXFULL (0): State machine RX FIFO is full
    io_ro_32 fstat;
    ...

Behavioral Changes

There were some behavioral changes in this release:

pico_sync

SDK 1.2.0 previously added recursive mutex support using the existing (previously non-recursive) mutex_ functions. This caused a performance regression, and the only clean way to fix the problem was to return the mutex_ functions to their pre-SDK 1.2.0 behavior, and split the recursive mutex functionality out into separate recursive_mutex_ functions with a separate recursive_mutex_ type.

Code using the SDK 1.2.0 recursive mutex functionality will need to be changed to use the new type and functions, however as a convenience, the pre-processor define PICO_MUTEX_ENABLE_SDK120_COMPATIBILITY may be set to 1 to retain the SDK 1.2.0 behavior at the cost of an additional performance penalty. The ability to use this pre-processor define will be removed in a subsequent SDK version.

pico_platform

• pico.h and its dependencies have been slightly refactored so it can be included by assembler code as well as C/C++ code. Thie ensures that assembler code and C/C++ code follow the same board configuration/override order and see the same configuration defines. This should not break any existing code, but is notable enough to mention.
• pico/platform.h is now fully documented.

pico_standard_link

-Wl,max-page-size=4096 is now passed to the linker, which is beneficial to certain users and should have no discernible impact on the rest.

Other Notable Improvements

hardware_base

• Added xip_noalloc_alias(addr), xip_nocache_alias(addr), xip_nocache_noalloc_alias(addr) macros for converting a flash address between XIP aliases (similar to the hw_xxx_alias(addr) macros).

hardware_dma

• Added dma_timer_claim(), dma_timer_unclaim(), dma_claim_unused_timer() and dma_timer_is_claimed() to manage ownership of DMA timers.
• Added dma_timer_set_fraction() and dma_get_timer_dreq() to facilitate pacing DMA transfers using DMA timers.

hardware_i2c

• Added i2c_get_dreq() function to facilitate configuring DMA transfers to/from an I2C instance.

hardware_irq

• Added irq_get_priority().
• Fixed implementation when PICO_DISABLE_SHARED_IRQ_HANDLERS=1 is specified, and allowed irq_add_shared_handler to be used in this case (as long as there is only one handler - i.e. it behaves exactly like irq_set_exclusive_handler),
• Sped up IRQ priority initialization which was slowing down per core initialization.

hardware_pio

• pio_encode_ functions in hardware/pico_instructions.h are now documented.

hardware_pwm

• Added pwm_get_dreq() function to facilitate configuring DMA transfers to a PWM slice.

hardware_spi

• Added spi_get_dreq() function to facilitate configuring DMA transfers to/from an SPI instance.

hardware_uart

• Added uart_get_dreq() function to facilitate configuring DMA transfers to/from a UART instance.

hardware_watchdog

• Added watchdog_enable_caused_reboot() to distinguish a watchdog reboot caused by a watchdog timeout after calling watchdog_enable() from other watchdog reboots (e.g. that are performed when a UF2 is dragged onto a device in BOOTSEL mode).

pico_bootrom

• Added new constants and function signature typedefs to pico/bootrom.h to facilitate calling bootrom functions directly.

pico_multicore

• Improved documentation in pico/multicore.h; particularly, multicore_lockout_ functions are newly documented.

pico_platform

• PICO_RP2040 is now defined to 1 in PICO_PLATFORM=rp2040 (i.e. normal) builds.

pico_stdio

• Added puts_raw() and putchar_raw() to skip CR/LF translation if enabled.
• Added stdio_usb_connected() to detect CDC connection when using stdio_usb.
• Added PICO_STDIO_USB_CONNECT_WAIT_TIMEOUT_MS define that can be set to wait for a CDC connection to be established during initialization of stdio_usb. Note: value -1 means indefinite. This can be used to prevent initial program output being lost, at the cost of requiring an active CDC connection.
• Fixed semihosting_putc which was completely broken.

pico_usb_reset_interface

• This new library contains pico/usb_reset_interface.h split out from stdio_usb to facilitate inclusion in external projects.

CMake build

• OUTPUT_NAME target property is now respected when generating supplemental files (.BIN, .HEX, .MAP, .UF2)

pioasm

• Operator precedence of *, /, -, + have been fixed
• Incorrect MicroPython output has been fixed.

elf2uf2

• A bug causing an error with binaries produces by certain other languages has been fixed.

SDK version 1.2.0

This release contains numerous bug fixes and documentation improvements. Additionally it contains the following improvements/notable changes:

Updated TinyUSB to 0.10.1

The lib/tinyusb submodule has been updated from 0.8.0 and now tracks upstream https://github.com/hathach/tinyusb.git. It is worth making sure you do a

git submodule sync
git submodule update

to make sure you are correctly tracking upstream TinyUSB if you are not checking out a clean pico-sdk repository.

Note also that moving ffrom TinyUSB 0.8.0 to TinyUSB 0.10.1 may require some minor changes to your USB code.

New/improved board headers

• New board headers support for PICO_BOARDs arduino_nano_rp240_connect, pimoroni_picolipo_4mb and pimoroni_picolipo_16mb
• Missing/new #defines for default SPI and I2C pins have been added

Added CMSIS core headers

CMSIS core headers (e.g. core_cm0plus.h and RP2040.h) are made available via cmsis_core INTERFACE library. Additionally, CMSIS standard exception naming is available via PICO_CMSIS_RENAME_EXCEPTIONS=1

API improvements

pico_sync

• Added support for recursive mutexes via recursive_mutex_init() and auto_init_recursive_mutex()
• Added mutex_enter_timeout_us()
• Added critical_section_deinit()
• Added sem_acquire_timeout_ms() and sem_acquire_block_until()

hardware_adc

• Added adc_get_selected_input()

hardware_clocks

• clock_get_hz() now returns actual achieved frequency rather than desired frequency

hardware_dma

• Added dma_channel_is_claimed()
• Added new methods for configuring/acknowledging DMA IRQs. dma_irqn_set_channel_enabled(), dma_irqn_set_channel_mask_enabled(), dma_irqn_get_channel_status(), dma_irqn_acknowledge_channel() etc.

hardware_exception

New library for setting ARM exception handlers:

• Added exception_set_exclusive_handler(), exception_restore_handler(), exception_get_vtable_handler()

hardware_flash

• Exposed previously private function flash_do_cmd() for low level flash command execution

hardware_gpio

• Added gpio_set_input_hysteresis_enabled(), gpio_is_input_hysteresis_enabled(), gpio_set_slew_rate(), gpio_get_slew_rate(), gpio_set_drive_strength(), gpio_get_drive_strength(). gpio_get_out_level(), gpio_set_irqover()

hardware_i2c

• Corrected a number of incorrect hardware register definitions
• A number of edge case in the i2c code fixed

hardware_interp

• Added interp_lane_is_claimed(), interp_unclaim_lane_mask()

hardware_irq

• Notably fixed the PICO_LOWEST/HIGHEST_IRQ_PRIORITY values which were backwards!

hardware_pio

• Added new methods for configuring/acknowledging PIO interrupts (pio_set_irqn_source_enabled(),
  pio_set_irqn_source_mask_enabled(), pio_interrupt_get(), pio_interrupt_clear() etc.)
• Added pio_sm_is_claimed()

hardware_spi

• Added spi_get_baudrate()
• Changed spi_init() to return the set/achieved baud rate rather than void
• Changed spi_is_writable() to return bool not size_t (it was always 1/0)

hardware_sync

• Notable documentation improvements for spin lock functions
• Added spin_lock_is_claimed()

hardware_timer

• Added busy_wait_ms() to match busy_wait_us()
• Added hardware_alarm_is_claimed()

pico_float/pico_double

• Correctly save/restore divider state if floating point is used from interrupts

pico_int64_ops

• Added PICO_INT64_OPS_IN_RAM flag to move code into RAM to avoid veneers when calling code is in RAM

pico_runtime

• Added ability to override panic function by setting PICO_PANIC_FUNCTION=foo to the use foo as the implementation, or setting
  PICO_PANIC_FUNCITON= to simply breakpoint, saving some code space

pico_unique_id

• Added pico_get_unique_board_id_string().

General code improvements

• Cleanup up some additional classes of compiler warnings
• Adding some missing const to method parameters

SVD

• USB DPRAM for device mode is now included

pioasm

• Added #pragma once to C/C++ output

RTOS interoperability

Improvements designed to make porting RTOSes either based on the SDK or supporting SDK code easier.

• Added PICO_DIVIDER_DISABLE_INTERRUPTS flag to optionally configure all uses of the hardware divider to be guarded by disabling interrupts, rather than requiring on the RTOS to save/restore the divider state on context switch
• Added new abstractions to pico/lock_core.h to allow an RTOS to inject replacement code for SDK based
  low level wait, notify and sleep/timeouts used by synchonization primitives in pico_sync and for sleep_ methods. If an RTOS implements these few simple methods, then all SDK semaphore, mutex, queue, sleep methods can be safely used both within/to/from RTOS tasks, but also to communicate with non RTOS task aware code, whether it be existing libraries and IRQ handlers or code running perhaps (though not necessarily) on the other core

CMake build changes

Substantive changes have been made to the CMake build, so if you are using a hand crafted non-CMake build, you will need to update your compile/link flags. Additionally changed some possibly confusing status messages from CMake build generation to be debug only

Boot Stage 2

• New boot stage 2 for AT25SF128A