NMEA2000_esp32xx.cpp

/*
NMEA2000_esp32xx.cpp

Copyright (c) 2015-2020 Timo Lappalainen, Kave Oy, www.kave.fi
Copyright (c) 2023 Jaume Clarens "jiauka"

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
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OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Inherited NMEA2000 object for ESP32xx modules. See also NMEA2000 library.

Thanks to Thomas Barth, barth-dev.de, who has written ESP32 CAN code. To avoid extra
libraries, I implemented his code directly to the NMEA2000_esp32 to avoid extra
can.h library, which may cause even naming problem.
*/

#include "esp_idf_version.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/queue.h"
#include "freertos/semphr.h"
#include "esp_err.h"
#include "esp_log.h"
#include "driver/twai.h"
#include "NMEA2000_esp32xx.h"

#if !defined(round)
  #include <math.h>
#endif
#if CORE_DEBUG_LEVEL >= ESP_LOG_DEBUG
  static const char *TAG = "TWAI_C3";
#endif

bool tNMEA2000_esp32xx::CanInUse=false;
tNMEA2000_esp32xx *pNMEA2000_esp32c3=0;
//*****************************************************************************
tNMEA2000_esp32xx::tNMEA2000_esp32xx(gpio_num_t _TxPin,  gpio_num_t _RxPin) :
  tNMEA2000(), IsOpen(false), TxPin(_TxPin), RxPin(_RxPin) {
}

//*****************************************************************************
bool tNMEA2000_esp32xx::CANSendFrame(unsigned long id, unsigned char len, const unsigned char *buf, bool /*wait_sent*/) {
  twai_message_t tx_msg;
  tx_msg.flags=0;
  tx_msg.extd=1;  /**< Extended Frame Format (29bit ID) */
  tx_msg.data_length_code=len>8?8:len;

  tx_msg.dlc_non_comp=len>8?1:0;  /**< Message's Data length code is larger than 8. This will break compliance with ISO 11898-1 */
  tx_msg.ss=1; /**< Transmit as a Single Shot Transmission. Unused for received. */
  tx_msg.identifier=id;
  memcpy(tx_msg.data,buf,len);
  return (twai_transmit(&tx_msg, 0)== ESP_OK);
}

//*****************************************************************************
bool tNMEA2000_esp32xx::CANOpen() {
    if (IsOpen) return true;

    if (CanInUse) return false; // currently prevent accidental second instance. Maybe possible in future.

    pNMEA2000_esp32c3=this;
    IsOpen=true;
    CAN_init();

    CanInUse=IsOpen;

  return IsOpen;
}

//*****************************************************************************
bool tNMEA2000_esp32xx::CANGetFrame(unsigned long &id, unsigned char &len, unsigned char *buf) {
  bool hasFrame=false;
  twai_message_t rx_msg;
  if ( twai_receive(&rx_msg, 0)==ESP_OK ) {
    hasFrame=true;
    id=rx_msg.identifier;
    len=rx_msg.data_length_code;
    memcpy(buf,rx_msg.data,len);
  }
  return hasFrame;
}

//*****************************************************************************
void tNMEA2000_esp32xx::CAN_init() {
  twai_timing_config_t t_config;
  twai_filter_config_t f_config = TWAI_FILTER_CONFIG_ACCEPT_ALL();
  twai_general_config_t g_config = TWAI_GENERAL_CONFIG_DEFAULT(TxPin, RxPin, TWAI_MODE_NORMAL);

#ifndef NMEA2000_MANUAL_TWAI_CONFIG

  t_config = TWAI_TIMING_CONFIG_250KBITS(); // default {.brp = 16, .tseg_1 = 15, .tseg_2 = 4, .sjw = 3, .triple_sampling = false}
#else // use hand configuration
  t_config.brp =16;
  t_config.tseg_1 =16;
  t_config.tseg_2 =3;
  t_config.sjw =1;
  t_config.triple_sampling=true;
#endif
  t_config.triple_sampling=true;
  ESP_ERROR_CHECK(twai_driver_install(&g_config, &t_config, &f_config));
  ESP_LOGD(TAG, "Driver installed");
  ESP_ERROR_CHECK(twai_start());
  ESP_LOGD(TAG, "Driver started");

}