Use the loop mode of the stm32can controller to test the sending and receiving function to see if it is normal. If it is normal, it means that the receiving driver of another object receiving data is not written well. If it is not normal, it means that at least the sending driver of this stm32can is not written well. You can first check whether the chip voltage is configured normally and whether it is damaged. ps: It is not recommended to use a 120 ohm terminal resistor when the communication distance is close. Otherwise, frames may be lost or the communication may fail