CAN开发板-CAN自收发实验，数码管从右到左分别是1~4位。数码管1、2位显示发送的数据，3、4位显示接收到的数据。每按一次中断按键发送数据值增一。--CAN CAN development board self-transceiver experimental digital tube from right to left are 1 to 4. 1,2 bit digital tube display data sent, 3,4-bit display data received. Each time you press the interrupt button to send the data value by one.