333 lines
8.6 KiB
C
333 lines
8.6 KiB
C
/* ****************************************************************************
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*
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* ESP32 platform interface for WS2812 LEDs.
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*
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* Copyright (c) 2017, Arnim Laeuger
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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* ****************************************************************************/
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#include "platform.h"
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#include "platform_rmt.h"
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#include "driver/rmt.h"
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#include "driver/gpio.h"
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#include "esp_log.h"
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#include "soc/periph_defs.h"
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#include "soc/rmt_reg.h"
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#undef WS2812_DEBUG
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// divider to generate 100ns base period from 80MHz APB clock
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#define WS2812_CLKDIV (100 * 80 /1000)
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// descriptor for a ws2812 chain
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typedef struct {
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bool valid;
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uint8_t gpio;
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bool sendreset;
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rmt_item32_t reset;
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rmt_item32_t bits[2];
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const uint8_t *data;
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size_t len;
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uint8_t bitpos;
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} ws2812_chain_t;
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// chain descriptor array
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static ws2812_chain_t ws2812_chains[RMT_CHANNEL_MAX];
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// Callback function to convert GRB data to pulse lengths.
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static void ws2812_convert(const void *src, rmt_item32_t *dest, size_t src_size, size_t wanted_num, size_t *translated_size, size_t *item_num)
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{
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size_t cnt_in;
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size_t cnt_out;
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const uint8_t *pucData;
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uint8_t ucData;
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uint8_t ucBitPos;
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esp_err_t tStatus;
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void *pvContext;
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ws2812_chain_t *ptContext;
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uint8_t ucBit;
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cnt_in = 0;
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cnt_out = 0;
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if( dest!=NULL && wanted_num>0 )
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{
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tStatus = rmt_translator_get_context(item_num, &pvContext);
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if( tStatus==ESP_OK )
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{
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ptContext = (ws2812_chain_t *)pvContext;
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if( ptContext->sendreset==true )
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{
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dest[cnt_out++] = ptContext->reset;
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ptContext->sendreset = false;
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}
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if( src!=NULL && src_size>0 )
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{
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ucBitPos = ptContext->bitpos;
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/* Each bit of the input data is converted into one RMT item. */
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pucData = (const uint8_t*)src;
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/* Get the current byte. */
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ucData = pucData[cnt_in] << ucBitPos;
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while( cnt_in<src_size && cnt_out<wanted_num )
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{
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/* Get the current bit. */
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ucBit = (ucData & 0x80U) >> 7U;
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/* Translate the bit to a WS2812 input code. */
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dest[cnt_out++] = ptContext->bits[ucBit];
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/* Move to the next bit. */
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++ucBitPos;
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if( ucBitPos<8U )
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{
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ucData <<= 1;
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}
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else
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{
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ucBitPos = 0U;
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++cnt_in;
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ucData = pucData[cnt_in];
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}
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}
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ptContext->bitpos = ucBitPos;
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}
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}
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}
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*translated_size = cnt_in;
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*item_num = cnt_out;
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}
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int platform_ws2812_setup( uint8_t gpio_num, uint32_t reset, uint32_t t0h, uint32_t t0l, uint32_t t1h, uint32_t t1l, const uint8_t *data, size_t len )
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{
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int channel;
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if ((channel = platform_rmt_allocate( 1, RMT_MODE_TX )) >= 0) {
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ws2812_chain_t *chain = &(ws2812_chains[channel]);
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rmt_item32_t tRmtItem;
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uint32_t half;
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chain->valid = true;
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chain->gpio = gpio_num;
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chain->len = len;
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chain->data = data;
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chain->bitpos = 0;
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// Send a reset if "reset" is not 0.
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chain->sendreset = (reset != 0);
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// Construct the RMT item for a reset.
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tRmtItem.level0 = 0;
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tRmtItem.level1 = 0;
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// The reset duration must fit into one RMT item. This leaves 2*15 bit,
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// which results in a maximum of 0xfffe .
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if (reset>0xfffe)
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{
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reset = 0xfffe;
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}
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if (reset>0x7fff)
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{
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tRmtItem.duration0 = 0x7fff;
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tRmtItem.duration1 = reset - 0x7fff;
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}
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else
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{
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half = reset >> 1U;
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tRmtItem.duration0 = half;
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tRmtItem.duration1 = reset - half;
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}
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chain->reset = tRmtItem;
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// Limit the bit times to the available 15 bits.
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// The values must not be 0.
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if( t0h==0 )
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{
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t0h = 1;
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}
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else if( t0h>0x7fffU )
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{
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t0h = 0x7fffU;
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}
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if( t0l==0 )
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{
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t0l = 1;
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}
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else if( t0l>0x7fffU )
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{
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t0l = 0x7fffU;
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}
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if( t1h==0 )
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{
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t1h = 1;
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}
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else if( t1h>0x7fffU )
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{
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t1h = 0x7fffU;
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}
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if( t1l==0 )
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{
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t1l = 1;
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}
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else if( t1l>0x7fffU )
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{
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t1l = 0x7fffU;
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}
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// Construct the RMT item for a 0 bit.
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tRmtItem.level0 = 1;
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tRmtItem.duration0 = t0h;
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tRmtItem.level1 = 0;
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tRmtItem.duration1 = t0l;
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chain->bits[0] = tRmtItem;
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// Construct the RMT item for a 1 bit.
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tRmtItem.level0 = 1;
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tRmtItem.duration0 = t1h;
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tRmtItem.level1 = 0;
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tRmtItem.duration1 = t1l;
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chain->bits[1] = tRmtItem;
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#ifdef WS2812_DEBUG
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ESP_LOGI("ws2812", "Setup done for gpio %d on RMT channel %d", gpio_num, channel);
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#endif
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return PLATFORM_OK;
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}
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return PLATFORM_ERR;
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}
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int platform_ws2812_release( void )
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{
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for (rmt_channel_t channel = 0; channel < RMT_CHANNEL_MAX; channel++) {
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ws2812_chain_t *chain = &(ws2812_chains[channel]);
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if (chain->valid) {
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rmt_driver_uninstall( channel );
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platform_rmt_release( channel );
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chain->valid = false;
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// attach GPIO to pin, driving 0
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gpio_set_level( chain->gpio, 0 );
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gpio_set_direction( chain->gpio, GPIO_MODE_DEF_OUTPUT );
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gpio_matrix_out( chain->gpio, SIG_GPIO_OUT_IDX, 0, 0 );
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}
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}
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return PLATFORM_OK;
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}
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int platform_ws2812_send( void )
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{
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rmt_config_t rmt_tx;
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int res = PLATFORM_OK;
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// common settings
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rmt_tx.mem_block_num = 1;
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rmt_tx.clk_div = WS2812_CLKDIV;
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rmt_tx.tx_config.loop_en = false;
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rmt_tx.tx_config.carrier_en = false;
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rmt_tx.tx_config.idle_level = 0;
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rmt_tx.tx_config.idle_output_en = true;
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rmt_tx.rmt_mode = RMT_MODE_TX;
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rmt_tx.flags = 0;
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// configure selected RMT channels
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for (rmt_channel_t channel = 0; channel < RMT_CHANNEL_MAX && res == PLATFORM_OK; channel++) {
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if (ws2812_chains[channel].valid) {
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rmt_tx.channel = channel;
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rmt_tx.gpio_num = ws2812_chains[channel].gpio;
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if (rmt_config( &rmt_tx ) != ESP_OK) {
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res = PLATFORM_ERR;
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break;
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}
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if (rmt_driver_install( channel, 0, 0 /*PLATFORM_RMT_INTR_FLAGS*/ ) != ESP_OK) {
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res = PLATFORM_ERR;
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break;
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}
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if (rmt_translator_init( channel, ws2812_convert) != ESP_OK) {
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res = PLATFORM_ERR;
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break;
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}
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if (rmt_translator_set_context( channel, &(ws2812_chains[channel])) != ESP_OK) {
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res = PLATFORM_ERR;
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break;
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}
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}
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}
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#if SOC_RMT_SUPPORT_TX_SYNCHRO
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for (rmt_channel_t channel = 0; channel < RMT_CHANNEL_MAX && res == PLATFORM_OK; channel++) {
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if (ws2812_chains[channel].valid) {
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if (rmt_add_channel_to_group( channel ) != ESP_OK) {
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res = PLATFORM_ERR;
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break;
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}
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}
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}
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#endif
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// start selected channels one by one
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for (rmt_channel_t channel = 0; channel < RMT_CHANNEL_MAX && res == PLATFORM_OK; channel++) {
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if (ws2812_chains[channel].valid) {
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if (rmt_write_sample( channel,
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ws2812_chains[channel].data,
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ws2812_chains[channel].len,
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false ) != ESP_OK) {
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res = PLATFORM_ERR;
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break;
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}
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}
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}
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// wait for all channels to finish
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for (rmt_channel_t channel = 0; channel < RMT_CHANNEL_MAX; channel++) {
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if (ws2812_chains[channel].valid) {
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rmt_wait_tx_done( channel, portMAX_DELAY );
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}
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}
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#if SOC_RMT_SUPPORT_TX_SYNCHRO
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for (rmt_channel_t channel = 0; channel < RMT_CHANNEL_MAX; channel++) {
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if (ws2812_chains[channel].valid) {
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if (rmt_remove_channel_from_group( channel ) != ESP_OK) {
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res = PLATFORM_ERR;
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break;
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}
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}
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}
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#endif
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return res;
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}
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void platform_ws2812_init( void )
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{
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for (rmt_channel_t channel = 0; channel < RMT_CHANNEL_MAX; channel++) {
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ws2812_chains[channel].valid = false;
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}
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}
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