This documentation will introduce how to use the uart of 40PIN headers.
Check Uart Hardware PINs
Uart PIN in 40 PINs header is PIN15 and PIN16:
Enable Uart Node
Enable uart node via device tree overlays. Edit /boot/env.txt to add uartX to overlays.
e.g.
1 | overlays=uart4 pwm_ao_a pwm_f i2c0 |
e.g.
- VIM1/VIM2/VIM4 - uar4
- VIM3/VIM3L - uart3
Reboot to take effect.
Check the Uart Device Node
After reboot, you will see the uart device node.
e.g.
- VIM1/VIM2/VIM4 - /dev/ttyS4
- VIM3/VIM3L - /dev/ttyS3