Atomic CAN Base Arduino 使用チュートリアル

#include <M5Unified.h>
#include <M5GFX.h>
#include "driver/twai.h"

const gpio_num_t MCU_CAN_TXD = GPIO_NUM_5;
const gpio_num_t MCU_CAN_RXD = GPIO_NUM_6;

void setup() {
  M5.begin();
  M5.Display.clear();
  M5.Display.setFont(&fonts::FreeMonoBold12pt7b);
  Serial.begin(115200);

  twai_general_config_t g_config = TWAI_GENERAL_CONFIG_DEFAULT(MCU_CAN_TXD, MCU_CAN_RXD, TWAI_MODE_NORMAL);
  twai_timing_config_t t_config = TWAI_TIMING_CONFIG_500KBITS();
  twai_filter_config_t f_config = TWAI_FILTER_CONFIG_ACCEPT_ALL();

  if (twai_driver_install(&g_config, &t_config, &f_config) == ESP_OK && twai_start() == ESP_OK) {
    Serial.println("\nCAN ready. ");
  } else {
    Serial.println("\nCAN init failed. ");
    while (1) delay(1000);
  }
  
  M5.Display.drawCenterString("CAN", 64, 50);
}

void loop() {
  // transmit
  twai_message_t tx_msg = {};
  tx_msg.extd = 0;            // 0 = standard frame, 1 = extended frame
  tx_msg.identifier = 0x123;  // 11-bit standard ID, change it on another device
  tx_msg.data_length_code = 2;
  tx_msg.data[0] = 0xAA;  // change it on another device
  tx_msg.data[1] = 0xBB;  // change it on another device

  if (twai_transmit(&tx_msg, pdMS_TO_TICKS(100)) == ESP_OK) {
    Serial.println("TX OK");
  } else {
    Serial.println("TX failed");
  }

  // receive (non-blocking)
  twai_message_t rx_msg;
  if (twai_receive(&rx_msg, pdMS_TO_TICKS(10)) == ESP_OK) {
    Serial.print("RX: ");
    for (int i = 0; i < rx_msg.data_length_code; i++) Serial.printf("%02X ", rx_msg.data[i]);
    Serial.printf("(ext=%d, id=0x%X, dlc=%d)", rx_msg.extd, rx_msg.identifier, rx_msg.data_length_code);
    Serial.println();
  }

  delay(2000);
}