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Diff for: ‎CMakeLists.txt

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idf_component_register(
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SRCS "ws2812.c"
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INCLUDE_DIRS include
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)

Diff for: ‎LICENSE

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This is free and unencumbered software released into the public domain.
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Anyone is free to copy, modify, publish, use, compile, sell, or
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distribute this software, either in source code form or as a compiled
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binary, for any purpose, commercial or non-commercial, and by any
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means.
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In jurisdictions that recognize copyright laws, the author or authors
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of this software dedicate any and all copyright interest in the
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software to the public domain. We make this dedication for the benefit
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of the public at large and to the detriment of our heirs and
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successors. We intend this dedication to be an overt act of
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relinquishment in perpetuity of all present and future rights to this
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software under copyright law.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
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OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
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ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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OTHER DEALINGS IN THE SOFTWARE.
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For more information, please refer to <http://unlicense.org>

Diff for: ‎README.md

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# ESP32 component: WS2812 LED driver
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ESP32 component for controlling WS2812 or compatible ("Neopixel") addressable LEDs using the RMT peripheral of the ESP32.
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Based on code from https://github.com/JSchaenzle/ESP32-NeoPixel-WS2812-RMT.
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Licensed using the "Unlicense". This software can be considered public domain.

Diff for: ‎include/ws2812.h

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#pragma once
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#include <stdint.h>
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#include <esp_err.h>
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#include <driver/gpio.h>
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__BEGIN_DECLS
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/**
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* Initialize the WS2812 driver.
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* @return ESP_OK on success; any other value indicates an error
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*/
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extern esp_err_t ws2812_init(gpio_num_t aGpioPin);
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/**
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* Enable power to the WS2812 bar.
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* @return ESP_OK on success; any other value indicates an error
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*/
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extern esp_err_t ws2812_enable(int gpio_pin);
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/**
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* Disable power to the WS2812 bar.
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* @return ESP_OK on success; any other value indicates an error
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*/
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extern esp_err_t ws2812_disable(void);
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/**
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* Send color-data to the WS2812 bus.
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* @param data the data-bytes to send on the bus.
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* @param len the data-length.
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* @return ESP_OK on success; any other value indicates an error
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*/
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extern esp_err_t ws2812_send_data(uint8_t *data, int len);
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__END_DECLS

Diff for: ‎ws2812.c

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//This driver uses the ESP32 RMT peripheral to drive "Neopixel" compatible LEDs
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//The usage of the RMT peripheral has been implemented using work by JSchaenzie:
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//you can find his work at https://github.com/JSchaenzle/ESP32-NeoPixel-WS2812-RMT
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#include <sdkconfig.h>
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#include <stdbool.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <string.h>
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#include <freertos/FreeRTOS.h>
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#include <freertos/task.h>
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#include <esp_err.h>
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#include <esp_log.h>
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#include <driver/gpio.h>
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#include <driver/rmt.h>
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static const char *TAG = "ws2812";
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#define WS2812_RMT_CHANNEL RMT_CHANNEL_0
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#define T0H 14 // 0 bit high time
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#define T1H 52 // 1 bit high time
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#define TL 52 // low time for either bit
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static bool gActive = false;
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rmt_item32_t* gBuffer = NULL;
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int gBufferLength = 0;
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gpio_num_t gPin;
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esp_err_t ws2812_init(gpio_num_t aGpioPin) {
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if (gActive) return ESP_OK;
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gpio_config_t io_conf = {
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.intr_type = GPIO_INTR_DISABLE,
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.mode = GPIO_MODE_OUTPUT,
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.pin_bit_mask = 1LL << aGpioPin,
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.pull_down_en = 0,
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.pull_up_en = 0,
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};
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esp_err_t res = gpio_config(&io_conf);
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if (res != ESP_OK) return res;
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rmt_config_t config;
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config.rmt_mode = RMT_MODE_TX;
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config.channel = WS2812_RMT_CHANNEL;
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config.gpio_num = aGpioPin;
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config.mem_block_num = 3;
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config.tx_config.loop_en = false;
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config.tx_config.carrier_en = false;
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config.tx_config.idle_output_en = true;
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config.tx_config.idle_level = 0;
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config.clk_div = 2;
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res = rmt_config(&config);
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if (res != ESP_OK) return res;
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res = rmt_driver_install(config.channel, 0, 0);
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if (res != ESP_OK) return res;
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gActive = true;
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gPin = aGpioPin;
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return ESP_OK;
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}
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esp_err_t ws2812_deinit(void) {
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if (!gActive) return ESP_OK;
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esp_err_t res = rmt_driver_uninstall(WS2812_RMT_CHANNEL);
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if (res != ESP_OK) return res;
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gpio_config_t io_conf = {
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.intr_type = GPIO_INTR_DISABLE,
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.mode = GPIO_MODE_INPUT,
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.pin_bit_mask = 1LL << gPin,
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.pull_down_en = 0,
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.pull_up_en = 0,
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};
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res = gpio_config(&io_conf);
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if (res != ESP_OK) return res;
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gActive = false;
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return ESP_OK;
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}
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esp_err_t ws2812_prepare_data(uint8_t *data, int len)
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{
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if (gBuffer != NULL) return ESP_FAIL;
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gBuffer = calloc(len * 8, sizeof(rmt_item32_t));
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if (gBuffer == NULL) return ESP_FAIL;
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gBufferLength = len * 8;
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for (uint32_t pos = 0; pos < len; pos++) {
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uint32_t mask = 1 << 7;
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for (uint8_t i = 0; i < 8; i++) {
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bool bit = data[pos] & mask;
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gBuffer[pos*8 + i] = bit ?
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(rmt_item32_t){{{T1H, 1, TL, 0}}} :
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(rmt_item32_t){{{T0H, 1, TL, 0}}};
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mask >>= 1;
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}
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}
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return ESP_OK;
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}
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esp_err_t ws2812_free_data() {
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if (!gBuffer) return ESP_FAIL;
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free(gBuffer);
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gBuffer = NULL;
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gBufferLength = 0;
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return ESP_OK;
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}
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esp_err_t ws2812_send_data(uint8_t *data, int len)
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{
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if (!gActive) return ESP_FAIL;
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esp_err_t res = ws2812_prepare_data(data, len);
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if (res != ESP_OK) return res;
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res = rmt_write_items(WS2812_RMT_CHANNEL, gBuffer, gBufferLength, false);
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if (res != ESP_OK) {
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ws2812_free_data();
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return res;
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}
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res = rmt_wait_tx_done(WS2812_RMT_CHANNEL, portMAX_DELAY);
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if (res != ESP_OK) {
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ws2812_free_data();
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return res;
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}
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res = ws2812_free_data();
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return res;
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}

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