dev_zh_rmt/main/main.c

#include "stdio.h"
#include "driver/rmt_rx.h"
#include "driver/gpio.h"
// #include "freertos/queue.h"
// #include "freertos/task.h"
#include "freertos/FreeRTOS.h"

// static bool example_rmt_rx_done_callback(rmt_channel_handle_t channel, const rmt_rx_done_event_data_t *edata, void *user_data)
// {
//     // BaseType_t high_task_wakeup = pdFALSE;
//     // QueueHandle_t receive_queue = (QueueHandle_t)user_data;
//     // // send the received RMT symbols to the parser task
//     // xQueueSendFromISR(receive_queue, edata, &high_task_wakeup);
//     // // return whether any task is woken up
//     // return high_task_wakeup == pdTRUE;
// }

void app_main(void)
{
    gpio_config_t config;
    config.intr_type = GPIO_INTR_DISABLE;
    config.mode = GPIO_MODE_INPUT;
    config.pin_bit_mask = (1ULL << 5);
    config.pull_down_en = GPIO_PULLDOWN_DISABLE;
    config.pull_up_en = GPIO_PULLUP_ENABLE;
    gpio_config(&config);
    gpio_set_direction(5, GPIO_MODE_OUTPUT);
    gpio_set_level(5, 0);
    vTaskDelay(10 / portTICK_PERIOD_MS);
    // gpio_set_level(5, 1);
    gpio_set_direction(5, GPIO_MODE_INPUT);

    rmt_channel_handle_t rx_channel = NULL;
    rmt_rx_channel_config_t rx_chan_config = {
        .gpio_num = 5,                    // GPIO number
        .clk_src = RMT_CLK_SRC_DEFAULT,   // select source clock
        .resolution_hz = 1 * 1000 * 1000, // 1MHz tick resolution, i.e. 1 tick = 1us
        .mem_block_symbols = 64,          // memory block size, 64 * 4 = 256Bytes
        .flags.invert_in = false,         // don't invert input signal
        .flags.with_dma = false,          // don't need DMA backend
        // .flags.io_loop_back=false,
        // .intr_priority=0,
    };
    ESP_ERROR_CHECK(rmt_new_rx_channel(&rx_chan_config, &rx_channel));

    // QueueHandle_t receive_queue = xQueueCreate(1, sizeof(rmt_rx_done_event_data_t));
    // rmt_rx_event_callbacks_t cbs = {
    //     .on_recv_done = example_rmt_rx_done_callback,
    // };
    // ESP_ERROR_CHECK(rmt_rx_register_event_callbacks(rx_channel, &cbs, NULL));

    // the following timing requirement is based on NEC protocol
    rmt_receive_config_t receive_config = {
        .signal_range_min_ns = 20000, // the shortest duration for NEC signal is 560us, 1250ns < 560us, valid signal won't be treated as noise
        .signal_range_max_ns = 90000, // the longest duration for NEC signal is 9000us, 12000000ns > 9000us, the receive won't stop early
    };

    rmt_symbol_word_t raw_symbols[64]; // 64 symbols should be sufficient for a standard NEC frame
    // ready to receive
    ESP_ERROR_CHECK(rmt_receive(rx_channel, raw_symbols, sizeof(raw_symbols), &receive_config));
    // wait for RX done signal
    for (uint8_t i = 0; i < 64; ++i)
    {
        printf("%d - %d, %d, %d, %d\n", raw_symbols[i].duration0, raw_symbols[i].level0, raw_symbols[i].duration1, raw_symbols[i].level1);
    }
}