Initial support for ESP32-C3-Lyra-V2 dev board

See https://docs.espressif.com/projects/esp-adf/en/latest/design-guide/dev-boards/user-guide-esp32-c3-lyra.html
This commit adds support for audio out and the status LED.

The audio out on this board is in PDM over the I2S encoder hardware.

It's not 100% clear to me why the default neopixel_write implementation
doesn't work, but it seems that deleting the RMT channel triggers some
sort of glitch signal that clears the WS2812C LED.

Author: gychang

ports/espressif/boards/espressif_esp32c3_lyra_v2/board.c

@@ -0,0 +1,9 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2021 microDev
+//
+// SPDX-License-Identifier: MIT
+
+#include "supervisor/board.h"
+
+// Use the MP_WEAK supervisor/shared/board.c versions of routines not defined here.

ports/espressif/boards/espressif_esp32c3_lyra_v2/mpconfigboard.h

@@ -0,0 +1,26 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2021 microDev
+//
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+// Board setup
+#define MICROPY_HW_BOARD_NAME       "ESP32-C3-Lyra-V2"
+#define MICROPY_HW_MCU_NAME         "ESP32-C3N4"
+
+// Status LED
+#define MICROPY_HW_NEOPIXEL         (&pin_GPIO10)
+#define MICROPY_HW_NEOPIXEL_COUNT   (1)
+
+// Default bus pins
+#define DEFAULT_UART_BUS_RX         (&pin_GPIO20)
+#define DEFAULT_UART_BUS_TX         (&pin_GPIO21)
+
+// Serial over UART
+#define CIRCUITPY_CONSOLE_UART_RX               DEFAULT_UART_BUS_RX
+#define CIRCUITPY_CONSOLE_UART_TX               DEFAULT_UART_BUS_TX
+
+// Audio out as PDM over IS2S
+#define CIRCUITPY_AUDIOBUSIO_PDMOUT (1)

ports/espressif/boards/espressif_esp32c3_lyra_v2/mpconfigboard.mk

@@ -0,0 +1,14 @@
+CIRCUITPY_CREATOR_ID = 0x000C303A
+CIRCUITPY_CREATION_ID = 0x00C3A000
+
+IDF_TARGET = esp32c3
+
+CIRCUITPY_ESP_FLASH_MODE = qio
+CIRCUITPY_ESP_FLASH_FREQ = 80m
+CIRCUITPY_ESP_FLASH_SIZE = 4MB
+
+CIRCUITPY_LEGACY_4MB_FLASH_LAYOUT = 1
+
+CIRCUITPY_ESP_USB_SERIAL_JTAG = 0
+
+CIRCUITPY_AUDIOBUSIO_PDMOUT = 1

ports/espressif/boards/espressif_esp32c3_lyra_v2/pins.c

@@ -0,0 +1,41 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2021 microDev
+//
+// SPDX-License-Identifier: MIT
+
+#include "shared-bindings/board/__init__.h"
+
+static const mp_rom_map_elem_t board_module_globals_table[] = {
+    CIRCUITPYTHON_BOARD_DICT_STANDARD_ITEMS
+
+    { MP_ROM_QSTR(MP_QSTR_IO0), MP_ROM_PTR(&pin_GPIO0) },
+    { MP_ROM_QSTR(MP_QSTR_IO1), MP_ROM_PTR(&pin_GPIO1) },
+    { MP_ROM_QSTR(MP_QSTR_IO2), MP_ROM_PTR(&pin_GPIO2) },
+    { MP_ROM_QSTR(MP_QSTR_IO3), MP_ROM_PTR(&pin_GPIO3) },
+    { MP_ROM_QSTR(MP_QSTR_IO4), MP_ROM_PTR(&pin_GPIO4) },
+    { MP_ROM_QSTR(MP_QSTR_IO5), MP_ROM_PTR(&pin_GPIO5) },
+    { MP_ROM_QSTR(MP_QSTR_IO6), MP_ROM_PTR(&pin_GPIO6) },
+    { MP_ROM_QSTR(MP_QSTR_IO7), MP_ROM_PTR(&pin_GPIO7) },
+    { MP_ROM_QSTR(MP_QSTR_IO8), MP_ROM_PTR(&pin_GPIO8) },
+    { MP_ROM_QSTR(MP_QSTR_IO9), MP_ROM_PTR(&pin_GPIO9) },
+    { MP_ROM_QSTR(MP_QSTR_IO10), MP_ROM_PTR(&pin_GPIO10) },
+    { MP_ROM_QSTR(MP_QSTR_IO18), MP_ROM_PTR(&pin_GPIO18) },
+    { MP_ROM_QSTR(MP_QSTR_IO19), MP_ROM_PTR(&pin_GPIO19) },
+    { MP_ROM_QSTR(MP_QSTR_IO20), MP_ROM_PTR(&pin_GPIO20) },
+    { MP_ROM_QSTR(MP_QSTR_IO21), MP_ROM_PTR(&pin_GPIO21) },
+
+    { MP_ROM_QSTR(MP_QSTR_RX), MP_ROM_PTR(&pin_GPIO20) },
+    { MP_ROM_QSTR(MP_QSTR_TX), MP_ROM_PTR(&pin_GPIO21) },
+
+    { MP_ROM_QSTR(MP_QSTR_MTMS), MP_ROM_PTR(&pin_GPIO4) },
+    { MP_ROM_QSTR(MP_QSTR_MTDI), MP_ROM_PTR(&pin_GPIO5) },
+    { MP_ROM_QSTR(MP_QSTR_MTCK), MP_ROM_PTR(&pin_GPIO6) },
+    { MP_ROM_QSTR(MP_QSTR_MTDO), MP_ROM_PTR(&pin_GPIO7) },
+
+    { MP_ROM_QSTR(MP_QSTR_BUTTON), MP_ROM_PTR(&pin_GPIO9) },
+    { MP_ROM_QSTR(MP_QSTR_NEOPIXEL), MP_ROM_PTR(&pin_GPIO10) },
+
+    { MP_ROM_QSTR(MP_QSTR_UART), MP_ROM_PTR(&board_uart_obj) },
+};
+MP_DEFINE_CONST_DICT(board_module_globals, board_module_globals_table);

ports/espressif/boards/espressif_esp32c3_lyra_v2/sdkconfig

@@ -0,0 +1,14 @@
+#
+# Espressif IoT Development Framework Configuration
+#
+#
+# Component config
+#
+#
+# LWIP
+#
+# end of LWIP
+
+# end of Component config
+
+# end of Espressif IoT Development Framework Configuration

ports/espressif/common-hal/audiobusio/I2SOut.c

@@ -25,12 +25,29 @@
 
 #include "driver/i2s_std.h"
 
+#ifdef CIRCUITPY_AUDIOBUSIO_PDMOUT
+#include "driver/i2s_pdm.h"
+#endif
+
 // Caller validates that pins are free.
 void common_hal_audiobusio_i2sout_construct(audiobusio_i2sout_obj_t *self,
     const mcu_pin_obj_t *bit_clock, const mcu_pin_obj_t *word_select,
     const mcu_pin_obj_t *data, const mcu_pin_obj_t *main_clock, bool left_justified) {
     port_i2s_allocate_init(&self->i2s, left_justified);
 
+#ifdef CIRCUITPY_AUDIOBUSIO_PDMOUT
+    i2s_pdm_tx_config_t pdm_tx_cfg = {
+        .clk_cfg = I2S_PDM_TX_CLK_DEFAULT_CONFIG(16000),
+        .slot_cfg = I2S_PDM_TX_SLOT_DEFAULT_CONFIG(I2S_DATA_BIT_WIDTH_16BIT, I2S_SLOT_MODE_MONO),
+        .gpio_cfg = {
+            .dout = data->number,
+            .invert_flags = {
+                .clk_inv = false,
+            },
+        },
+    };
+    CHECK_ESP_RESULT(i2s_channel_init_pdm_tx_mode(self->i2s.handle, &pdm_tx_cfg));
+#else
     i2s_std_config_t i2s_config = {
         .clk_cfg = I2S_STD_CLK_DEFAULT_CONFIG(48000),
         .slot_cfg = I2S_STD_PHILIPS_SLOT_DEFAULT_CONFIG(I2S_DATA_BIT_WIDTH_16BIT, I2S_SLOT_MODE_STEREO),
@@ -43,6 +60,7 @@ void common_hal_audiobusio_i2sout_construct(audiobusio_i2sout_obj_t *self,
         }
     };
     CHECK_ESP_RESULT(i2s_channel_init_std_mode(self->i2s.handle, &i2s_config));
+ #endif
     self->bit_clock = bit_clock;
     self->word_select = word_select;
     self->mclk = main_clock;

ports/espressif/common-hal/audiobusio/__init__.c

@@ -19,10 +19,18 @@
 #define I2S_DMA_BUFFER_MAX_SIZE     4092
 // The number of DMA buffers to allocate
 #define CIRCUITPY_BUFFER_COUNT (3)
+
+#ifdef CIRCUITPY_AUDIOBUSIO_PDMOUT
+// The maximum DMA buffer size in frames (at mono 16-bit)
+#define CIRCUITPY_BUFFER_SIZE (I2S_DMA_BUFFER_MAX_SIZE / 8)
+// The number of output channels is fixed at 1
+#define CIRCUITPY_OUTPUT_SLOTS (1)
+#else
 // The maximum DMA buffer size in frames (at stereo 16-bit)
 #define CIRCUITPY_BUFFER_SIZE (I2S_DMA_BUFFER_MAX_SIZE / 4)
 // The number of output channels is fixed at 2
 #define CIRCUITPY_OUTPUT_SLOTS (2)
+#endif
 
 static void i2s_fill_buffer(i2s_t *self) {
     if (self->next_buffer_size == 0) {
@@ -31,7 +39,7 @@ static void i2s_fill_buffer(i2s_t *self) {
     }
     int16_t *output_buffer = (int16_t *)self->next_buffer;
     size_t output_buffer_size = self->next_buffer_size;
-    const size_t bytes_per_output_frame = 4;
+    const size_t bytes_per_output_frame = CIRCUITPY_OUTPUT_SLOTS * 2;
     size_t bytes_per_input_frame = self->channel_count * self->bytes_per_sample;
     if (!self->playing || self->paused || !self->sample || self->stopping) {
         memset(output_buffer, 0, self->next_buffer_size);
@@ -62,7 +70,8 @@ static void i2s_fill_buffer(i2s_t *self) {
         size_t sample_bytecount = self->sample_end - self->sample_data;
         // The framecount is the minimum of space left in the output buffer or left in the incoming sample.
         size_t framecount = MIN(output_buffer_size / bytes_per_output_frame, sample_bytecount / bytes_per_input_frame);
-        if (self->samples_signed && self->channel_count == 2) {
+
+        if (self->samples_signed && self->channel_count == CIRCUITPY_OUTPUT_SLOTS) {
             if (self->bytes_per_sample == 2) {
                 memcpy(output_buffer, self->sample_data, framecount * bytes_per_output_frame);
             } else {
@@ -165,8 +174,16 @@ void port_i2s_play(i2s_t *self, mp_obj_t sample, bool loop) {
     audiosample_reset_buffer(self->sample, false, 0);
 
     uint32_t sample_rate = audiosample_get_sample_rate(sample);
+
+#ifdef CIRCUITPY_AUDIOBUSIO_PDMOUT 
+    i2s_pdm_tx_clk_config_t clk_config = I2S_PDM_TX_CLK_DEFAULT_CONFIG(sample_rate);
+    CHECK_ESP_RESULT(i2s_channel_reconfig_pdm_tx_clock(self->handle, &clk_config));
+    size_t frame_size = sizeof(uint16_t);
+#else
     i2s_std_clk_config_t clk_config = I2S_STD_CLK_DEFAULT_CONFIG(sample_rate);
     CHECK_ESP_RESULT(i2s_channel_reconfig_std_clock(self->handle, &clk_config));
+    size_t frame_size = sizeof(uint32_t);
+#endif
 
     // preload the data
     self->playing = true;
@@ -183,12 +200,12 @@ void port_i2s_play(i2s_t *self, mp_obj_t sample, bool loop) {
         self->next_buffer = &starting_frame;
         self->next_buffer_size = sizeof(starting_frame);
         i2s_fill_buffer(self);
-        i2s_channel_preload_data(self->handle, &starting_frame, sizeof(uint32_t), &bytes_loaded);
+        i2s_channel_preload_data(self->handle, &starting_frame, frame_size, &bytes_loaded);
         preloaded += bytes_loaded;
     }
 
     // enable the channel
-    i2s_channel_enable(self->handle);
+    CHECK_ESP_RESULT(i2s_channel_enable(self->handle));
 
     // The IDF will call us back when there is a free DMA buffer.
 }

ports/espressif/common-hal/audiobusio/__init__.h

@@ -12,6 +12,10 @@
 
 #include "driver/i2s_std.h"
 
+#ifdef CIRCUITPY_AUDIOBUSIO_PDMOUT
+#include "driver/i2s_pdm.h"
+#endif
+
 typedef struct {
     mp_obj_t *sample;
     bool left_justified;

ports/espressif/common-hal/neopixel_write/__init__.c

@@ -126,11 +126,22 @@ void common_hal_neopixel_write(const digitalio_digitalinout_obj_t *digitalinout,
     // Update the next start to +2 ticks. It ensures that we've gone 300+ us.
     next_start_raw_ticks = port_get_raw_ticks(NULL) + 2;
 
+#if defined(CONFIG_IDF_TARGET_ESP32C3)
+    // Hold the pin, deleting the channel seems to glitch pixels into turning off.
+    gpio_hold_en(digitalinout->pin->number);
+#endif
+
     // Free channel again
     rmt_del_encoder(encoder);
     rmt_disable(channel);
     rmt_del_channel(channel);
     CHECK_ESP_RESULT(result);
+
     // Swap pin back to GPIO mode
     gpio_set_direction(digitalinout->pin->number, GPIO_MODE_OUTPUT);
+
+#if defined(CONFIG_IDF_TARGET_ESP32C3)
+    // Release hold
+    gpio_hold_dis(digitalinout->pin->number);
+#endif
 }