DShotRMT/src/dshot_config.cpp

#include "dshot_config.h"

// Function to initialize the RMT TX channel
dshot_result_t init_rmt_tx_channel(gpio_num_t gpio, rmt_channel_handle_t *out_channel, bool is_bidirectional)
{
    rmt_tx_channel_config_t tx_channel_config = {
        .gpio_num = gpio,
        .clk_src = DSHOT_CLOCK_SRC_DEFAULT,
        .resolution_hz = DSHOT_RMT_RESOLUTION,
        .mem_block_symbols = RMT_BUFFER_SYMBOLS,
        .trans_queue_depth = RMT_QUEUE_DEPTH,
    };

    rmt_transmit_config_t rmt_tx_config = {}; // Initialize all members to zero
    rmt_tx_config.loop_count = 0; // No automatic loops - real-time calculation
    rmt_tx_config.flags.eot_level = is_bidirectional ? 1 : 0;

    if (rmt_new_tx_channel(&tx_channel_config, out_channel) != DSHOT_OK)
    {
        return {false, dshot_msg_code_t::DSHOT_TX_INIT_FAILED};
    }

    if (rmt_enable(*out_channel) != DSHOT_OK)
    {
        return {false, dshot_msg_code_t::DSHOT_TX_INIT_FAILED};
    }

    return {true, dshot_msg_code_t::DSHOT_TX_INIT_SUCCESS};
}

// Function to initialize the RMT RX channel
dshot_result_t init_rmt_rx_channel(gpio_num_t gpio, rmt_channel_handle_t *out_channel, rmt_rx_event_callbacks_t *rx_event_callbacks, void *user_data)
{
    rmt_rx_channel_config_t rx_channel_config = {
        .gpio_num = gpio,
        .clk_src = DSHOT_CLOCK_SRC_DEFAULT,
        .resolution_hz = DSHOT_RMT_RESOLUTION,
        .mem_block_symbols = RMT_BUFFER_SYMBOLS,
    };

    rmt_receive_config_t rmt_rx_config = {
        .signal_range_min_ns = DSHOT_PULSE_MIN_NS,
        .signal_range_max_ns = DSHOT_PULSE_MAX_NS,
    };

    if (rmt_new_rx_channel(&rx_channel_config, out_channel) != DSHOT_OK)
    {
        return {false, dshot_msg_code_t::DSHOT_RX_INIT_FAILED};
    }

    if (rmt_rx_register_event_callbacks(*out_channel, rx_event_callbacks, user_data) != DSHOT_OK)
    {
        return {false, dshot_msg_code_t::DSHOT_CALLBACK_REGISTERING_FAILED};
    }

    if (rmt_enable(*out_channel) != DSHOT_OK)
    {
        return {false, dshot_msg_code_t::DSHOT_RX_INIT_FAILED};
    }

    // Start the receiver to wait for incoming telemetry data
    rmt_symbol_word_t rx_symbols[GCR_BITS_PER_FRAME];
    size_t rx_size_bytes = GCR_BITS_PER_FRAME * sizeof(rmt_symbol_word_t);
    if (rmt_receive(*out_channel, rx_symbols, rx_size_bytes, &rmt_rx_config) != DSHOT_OK)
    {
        return {false, dshot_msg_code_t::DSHOT_RECEIVER_FAILED};
    }

    return {true, dshot_msg_code_t::DSHOT_RX_INIT_SUCCESS};
}

// Function to initialize the DShot RMT encoder
dshot_result_t init_dshot_encoder(rmt_encoder_handle_t *out_encoder, const rmt_ticks_t &rmt_ticks, uint16_t pulse_level, uint16_t idle_level)
{
    rmt_bytes_encoder_config_t encoder_config = {
        .bit0 = {
            .duration0 = rmt_ticks.t0h_ticks,
            .level0 = pulse_level,
            .duration1 = rmt_ticks.t0l_ticks,
            .level1 = idle_level,
        },
        .bit1 = {
            .duration0 = rmt_ticks.t1h_ticks,
            .level0 = pulse_level,
            .duration1 = rmt_ticks.t1l_ticks,
            .level1 = idle_level,
        },
        .flags = {
            .msb_first = 1 // DShot is MSB first
        }};

    if (rmt_new_bytes_encoder(&encoder_config, out_encoder) != DSHOT_OK)
    {
        return {false, dshot_msg_code_t::DSHOT_ENCODER_INIT_FAILED};
    }

    return {true, dshot_msg_code_t::DSHOT_ENCODER_INIT_SUCCESS};
}