I am using NUCLEO STM32F103RB to learn CAN communication. In CubeMX, PB8 and PB9 were set to CAN_RX and CAN_TX, the baud rate is 500kbps, standard frame, and in Loopback mode. The USB_LP_CAN1_RX0_IQRHandler and CAN1_RX1_IRQHandler were enabled.  The ...