Merge pull request #5892 from tannewt/esp_neopixel

ESP NeoPixel fixes

Author: dhalbert

ports/atmel-samd/common-hal/neopixel_write/__init__.c

@@ -100,7 +100,7 @@ static void neopixel_send_buffer_core(volatile uint32_t *clraddr, uint32_t pinMa
         "");
 }
 
-uint64_t next_start_raw_ticks = 0;
+STATIC uint64_t next_start_raw_ticks = 0;
 
 void common_hal_neopixel_write(const digitalio_digitalinout_obj_t *digitalinout, uint8_t *pixels, uint32_t numBytes) {
     // This is adapted directly from the Adafruit NeoPixel library SAMD21G18A code:

ports/espressif/common-hal/microcontroller/Pin.c

@@ -36,20 +36,6 @@
 STATIC uint32_t never_reset_pins[2];
 STATIC uint32_t in_use[2];
 
-STATIC void floating_gpio_reset(gpio_num_t pin_number) {
-    // This is the same as gpio_reset_pin(), but without the pullup.
-    // Note that gpio_config resets the iomatrix to GPIO_FUNC as well.
-    gpio_config_t cfg = {
-        .pin_bit_mask = BIT64(pin_number),
-        .mode = GPIO_MODE_DISABLE,
-        .pull_up_en = false,
-        .pull_down_en = false,
-        .intr_type = GPIO_INTR_DISABLE,
-    };
-    gpio_config(&cfg);
-    PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[pin_number], 0);
-}
-
 void never_reset_pin_number(gpio_num_t pin_number) {
     if (pin_number == NO_PIN) {
         return;
@@ -72,7 +58,7 @@ void reset_pin_number(gpio_num_t pin_number) {
     never_reset_pins[pin_number / 32] &= ~(1 << pin_number % 32);
     in_use[pin_number / 32] &= ~(1 << pin_number % 32);
 
-    floating_gpio_reset(pin_number);
+    gpio_reset_pin(pin_number);
 }
 
 void common_hal_mcu_pin_reset_number(uint8_t i) {
@@ -93,7 +79,7 @@ void reset_all_pins(void) {
             (never_reset_pins[i / 32] & (1 << i % 32)) != 0) {
             continue;
         }
-        floating_gpio_reset(i);
+        gpio_reset_pin(i);
     }
     in_use[0] = never_reset_pins[0];
     in_use[1] = never_reset_pins[1];

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

@@ -43,20 +43,23 @@
 #include "py/mphal.h"
 #include "py/runtime.h"
 #include "shared-bindings/neopixel_write/__init__.h"
+#include "supervisor/port.h"
 #include "components/driver/include/driver/rmt.h"
 #include "peripherals/rmt.h"
 
-#define WS2812_T0H_NS (350)
-#define WS2812_T0L_NS (1000)
-#define WS2812_T1H_NS (1000)
-#define WS2812_T1L_NS (350)
-#define WS2812_RESET_US (280)
+// 416 ns is 1/3 of the 1250ns period of a 800khz signal.
+#define WS2812_T0H_NS (416)
+#define WS2812_T0L_NS (416 * 2)
+#define WS2812_T1H_NS (416 * 2)
+#define WS2812_T1L_NS (416)
 
 static uint32_t ws2812_t0h_ticks = 0;
 static uint32_t ws2812_t1h_ticks = 0;
 static uint32_t ws2812_t0l_ticks = 0;
 static uint32_t ws2812_t1l_ticks = 0;
 
+static uint64_t next_start_raw_ticks = 0;
+
 static void IRAM_ATTR ws2812_rmt_adapter(const void *src, rmt_item32_t *dest, size_t src_size,
     size_t wanted_num, size_t *translated_size, size_t *item_num) {
     if (src == NULL || dest == NULL) {
@@ -107,21 +110,29 @@ void common_hal_neopixel_write(const digitalio_digitalinout_obj_t *digitalinout,
     if (rmt_get_counter_clock(config.channel, &counter_clk_hz) != ESP_OK) {
         mp_raise_RuntimeError(translate("Could not retrieve clock"));
     }
-    float ratio = (float)counter_clk_hz / 1e9;
-    ws2812_t0h_ticks = (uint32_t)(ratio * WS2812_T0H_NS);
-    ws2812_t0l_ticks = (uint32_t)(ratio * WS2812_T0L_NS);
-    ws2812_t1h_ticks = (uint32_t)(ratio * WS2812_T1H_NS);
-    ws2812_t1l_ticks = (uint32_t)(ratio * WS2812_T1L_NS);
+    size_t ns_per_tick = 1e9 / counter_clk_hz;
+    ws2812_t0h_ticks = WS2812_T0H_NS / ns_per_tick;
+    ws2812_t0l_ticks = WS2812_T0L_NS / ns_per_tick;
+    ws2812_t1h_ticks = WS2812_T1H_NS / ns_per_tick;
+    ws2812_t1l_ticks = WS2812_T1L_NS / ns_per_tick;
 
     // Initialize automatic timing translator
     rmt_translator_init(config.channel, ws2812_rmt_adapter);
 
+    // Wait to make sure we don't append onto the last transmission. This should only be a tick or
+    // two.
+    while (port_get_raw_ticks(NULL) < next_start_raw_ticks) {
+    }
+
     // Write and wait to finish
     if (rmt_write_sample(config.channel, pixels, (size_t)numBytes, true) != ESP_OK) {
         mp_raise_RuntimeError(translate("Input/output error"));
     }
     rmt_wait_tx_done(config.channel, pdMS_TO_TICKS(100));
 
+    // 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;
+
     // Free channel again
     peripherals_free_rmt(config.channel);
     // Swap pin back to GPIO mode

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

@@ -98,6 +98,6 @@ void common_hal_neopixel_write(const digitalio_digitalinout_obj_t *digitalinout,
     gpio_init(digitalinout->pin->number);
     common_hal_digitalio_digitalinout_switch_to_output((digitalio_digitalinout_obj_t *)digitalinout, false, DRIVE_MODE_PUSH_PULL);
 
-    // Update the next start.
-    next_start_raw_ticks = port_get_raw_ticks(NULL) + 1;
+    // Update the next start to +2 ticks. This ensures we give it at least 300us.
+    next_start_raw_ticks = port_get_raw_ticks(NULL) + 2;
 }

supervisor/shared/status_leds.c

@@ -48,6 +48,7 @@ uint8_t rgb_status_brightness = 63;
 #define MICROPY_HW_NEOPIXEL_COUNT (1)
 #endif
 
+static uint64_t next_start_raw_ticks;
 static uint8_t status_neopixel_color[3 * MICROPY_HW_NEOPIXEL_COUNT];
 static digitalio_digitalinout_obj_t status_neopixel;
 
@@ -218,6 +219,10 @@ void status_led_init() {
 
 void status_led_deinit() {
     #ifdef MICROPY_HW_NEOPIXEL
+    // Make sure the pin stays low for the reset period. The pin reset may pull
+    // it up and stop the reset period.
+    while (port_get_raw_ticks(NULL) < next_start_raw_ticks) {
+    }
     common_hal_reset_pin(MICROPY_HW_NEOPIXEL);
 
     #elif defined(MICROPY_HW_APA102_MOSI) && defined(MICROPY_HW_APA102_SCK)
@@ -265,7 +270,7 @@ void new_status_color(uint32_t rgb) {
         status_neopixel_color[3 * i + 2] = rgb_adjusted & 0xff;
     }
     common_hal_neopixel_write(&status_neopixel, status_neopixel_color, 3 * MICROPY_HW_NEOPIXEL_COUNT);
-
+    next_start_raw_ticks = port_get_raw_ticks(NULL) + 2;
     #elif defined(MICROPY_HW_APA102_MOSI) && defined(MICROPY_HW_APA102_SCK)
     for (size_t i = 0; i < MICROPY_HW_APA102_COUNT; i++) {
         // Skip 4 + offset to skip the header bytes too.