u8_set_can_listen_id()

Description

u8_set_can_listen_id() allows you to configure the CAN ID (11 bit – standard ID) that the bootloader will be listening for at start-up. The bootloader expects to receive bootloader protocol messages with this CAN-ID. It is the CAN-ID that PC tools are using for communication to the target device [default 0x765].

Syntax

u8_set_can_listen_id( ou16_new_can_id );

Parameters

uint16_t ou16_new_can_id: the CAN ID of which we expect messages from the PC

Returns

uint8_t return value meaning:
0 – setting changed (accepted).
2 – the parameter ou16_new_can_id is out of range (0 … 0x7FF)

Example Code

This example shows how to read, set and store the ‘can listen id’ of the bootloader settings.

void setup()
{  
  Serial.begin();
  while (!Serial) 
  {
    yield(); // wait for PC CAN2SER-monitor to open 
  }
  uint16_t u16_can_listen_id = BOOTLOADER_SETTING.u16_get_can_listen_id();
  
  Serial.println("Current bootloader settings:");
  Serial.println(" - can listen id: 0x"+ String( u16_can_listen_id, HEX ));
  
  delay(2000);
  Serial.println("Modify the settings");
  BOOTLOADER_SETTING.u8_set_can_listen_id(0x765);
  
  delay(2000);
  Serial.println("Store the settings in flash");
  
  uint8_t u8_ret = BOOTLOADER_SETTING.u8_store_bootloader_settings();
  
  if(u8_ret != 0)
	Serial.println("Error writing into flash");
  
  Serial.println("DONE");
}

void loop () 
{
}

Notes and Warnings

Don’t forget to call the function u8_store_bootloader_settings() to write the changed settings into flash, so that the bootloader (and app.) has the new values at the next system start / reset.

It is recommended to leave the CAN Listen ID at its default value (0x765), because all tools and libraries use this ID by default. Change the can_listen_id ( = the send ID of the PC) only if it is really necessary. E.g. in case it is already used by another device on the same CAN bus.