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I do not have the required hardware to properly test it. All I can confirm is that it compiles and isn't crashing.

I added some more details on why alerts happen.

Anything i can help with to prove this is functional?
Here a picture of the testsystem i use (when not running it in a car):

@designer2k2 Hi, we're watching this and we will include it in upcoming release 2.0.6., release date will be in the 1st half of December.

Hello @Dazza0, if you will have some time please help with review of this. We would like to include this in next release. Thanks.

Hello @Dazza0, I will incorporate your requests by tomorrow

Hello @Dazza0, please take a look if the changes are ok like this

@Dazza0 i am lost with the squash topic, the github gui only allowed me to squash the last 3.
But i cannot do it on the others, there was a merge in between that somehow blocks this:

Any way thats possible to do on your end? Or give me a hint how i can resolve the error above?

@designer2k2 I think I see where the issue is.

It seems like the issue might be coming from this commit. It seems updates from upstream arduino-esp32 somehow got merged into the master branch of your local fork. If your Github GUI supports rebasing, it is usually possible to drop a particular commit during the rebase.

Alternatively:

• I could try override your branch from my side. But I think you'll need to explicitly allow that according to Github's docs
• You could try creating a new branch for these changes (recommended for future PRs). This way you can easily rebase your changes on top the latest master. But unfortunately, I think you'll need to create a new PR for that as I don't think it's possible to retarget an existing PR to a new branch.
• I can also create that branch/PR for you if you prefer (I'll be sure to keep you as the commit author).

yes there i clicked on the "Update branch" Button in the Gui, that was not good.

Could you create the branch/PR for me? Its not clear to me on how to do that.

@designer2k2 Squashing commits can be done by us when we will merge this so don't worry about that.

Update: I just see it's already done by @Dazza0. :)

In order to filter out and accept only specific message IDs, the statement "twai_filter_config_t f_config = TWAI_FILTER_CONFIG_ACCEPT_ALL();" has to be replaced with the appropriate "acceptance code and the acceptance mask". This is not well explained in the Espressif documentation. Has anyone managed to successfully code this information to limit the message IDs seen by an Arduino C++ application? If so, please share that part of your code. Thank you!

In order to filter out and accept only specific message IDs, the statement "twai_filter_config_t f_config = TWAI_FILTER_CONFIG_ACCEPT_ALL();" has to be replaced with the appropriate "acceptance code and the acceptance mask". This is not well explained in the Espressif documentation. Has anyone managed to successfully code this information to limit the message IDs seen by an Arduino C++ application? If so, please share that part of your code. Thank you!

Please refer to https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/twai.html#acceptance-filter

Thanks for responding to my question. However, I have read this particular section of the specs 17 times and still don't know how to code the masks and filters. There are several examples on the the Espressif forum and Github, but none that fully explains how to code Arduino C++ that accepts two or more IDs. The examples show shift-left (<<) by various amounts (<<3, <<5, <<21). There is no indication in the documentation that there is more than one acceptance filter (One indication implies there are a possible of up to 8 filters, while the Espressif documentation implies there is only one filter that can be used in single or dual mode (that would allow 2 acceptance codes). If there is the possibility to use more than two filters in single filter mode, then I can add more IDs later. The code I have accumulated, based on various sources, is shown below. If you could adjust this code so it accepts only IDs 743 and 7DF, it would be very much appreciated.

/* ESP32 TWAI receive example.
  Receive messages and sends them over serial.
  Connect a CAN bus transceiver to the RX/TX pins.
  For example: SN65HVD230
  TWAI_MODE_LISTEN_ONLY is used so that the TWAI controller will not influence the bus.
  The API gives other possible speeds and alerts:
  https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/twai.html
  Example output:
  -> Message received
  -> Message is in Standard Format
  -> ID is 604
  -> Byte 0 = 0 Byte 1 = f Byte 2 = 13 Byte 3 = 2 Byte 4 = 0 Byte 5 = 0 Byte 6 = 8 Byte 7 = 0
  created 05-11-2022 by Stephan Martin (designer2k2)
*/

#include "driver/twai.h"

//Pins used to connect to CAN bus transceiver:
#define rxPin 4
#define txPin 5
#define CAN_PWM_ADDR		0x743			// address of PWM message from ECU (unsolicited)
	unsigned char rxBuf[8];						// read buffer
	byte data[8] = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0xFE};	// write buffer

void setup() {
  // Start Serial:
  Serial.begin(115200);

  //Initialize configuration structures using macro initializers
  twai_general_config_t g_config = TWAI_GENERAL_CONFIG_DEFAULT((gpio_num_t)txPin, (gpio_num_t)rxPin, TWAI_MODE_LISTEN_ONLY);
  twai_timing_config_t t_config = TWAI_TIMING_CONFIG_500KBITS();  //Look in the api-reference for other speed sets.
  twai_filter_config_t f_config = TWAI_FILTER_CONFIG_ACCEPT_ALL();
  
// Configure acceptance code and mask for ID 0x743
	f_config.acceptance_code = 0x743 << 5;	// acceptance code for ID 743	
	f_config.acceptance_mask = 0x743 << 5;	// Mask with 11 bits set to 1 for full acceptance
	f_config.single_filter = true;			// single filter if "1", dual filter if "0"

// Configure acceptance code and mask for ID 0x7DF
	f_config.acceptance_code |= 0x7DF << 5; // Use bitwise OR to add the new acceptance code

/*  //Install TWAI driver (ChatGPT code) ***********************************************************
  if (twai_driver_install(&g_config, &t_config, &f_config) == ESP_OK) {
    Serial.println("Driver installed");
  } else {
    Serial.println("Failed to install driver");
    return;
  }
*/
  //Start TWAI driver
  if (twai_start() == ESP_OK) {
    Serial.println("Driver started");
  } else {
    Serial.println("Failed to start driver");
    return;
  }

  //Reconfigure alerts to detect Bus-Off error and RX queue full states
  uint32_t alerts_to_enable = TWAI_ALERT_ERR_PASS | TWAI_ALERT_BUS_ERROR | TWAI_ALERT_RX_QUEUE_FULL;
  if (twai_reconfigure_alerts(alerts_to_enable, NULL) == ESP_OK) {
    Serial.println("CAN Alerts reconfigured");
  } else {
    Serial.println("Failed to reconfigure alerts");
  }

}

void loop() 
{ //Check if alert happened
  uint32_t alerts_triggered;
  twai_read_alerts(&alerts_triggered, 1);
  if (alerts_triggered & TWAI_ALERT_ERR_PASS) {
    Serial.println("Alert: TWAI controller has become error passive.");
  } else if (alerts_triggered & TWAI_ALERT_BUS_ERROR) {
    Serial.println("Alert: A (Bit, Stuff, CRC, Form, ACK) error has occurred on the bus.");
  } else if (alerts_triggered & TWAI_ALERT_RX_QUEUE_FULL) {
    Serial.println("Alert: The RX queue is full causing a received frame to be lost.");
  }

  //Wait for message to be received:
  twai_message_t message;
  if (twai_receive(&message, pdMS_TO_TICKS(1000)) == ESP_OK) {
    Serial.println("Message received");
	twai_message_t message;
		
  } else {
    Serial.println("No message received");
    return;
  }

  //Process received message
  if (message.extd) {
    Serial.println("Message is in Extended Format");
  } else {
    Serial.println("Message is in Standard Format");
  }
  Serial.printf("ID is %x\n", message.identifier);
	if (!(message.rtr)) 
	{
	  
		if (message.identifier = CAN_PWM_ADDR)
		{	for (int i = 0; i < 8; i++)	
			{	Serial.printf("Byte %d = %x ", i, message.data[i]);
				rxBuf[i] = message.data[i];
			}
			Serial.println("");
// put application logic here to process the received message ID 743
		}
    }
}