| NuttX UART | PX4FMUv1 UART | PX4FMUv2 (Pixhawk) UART |
|---|---|---|
| /dev/ttyS0 | UART1 (NSH console) | IO DEBUG (RX only) |
| /dev/ttyS1 | UART2 | TELEM1 |
| /dev/ttyS2 | UART5 | TELEM2 |
| /dev/ttyS3 | UART6 | GPS |
| /dev/ttyS4 | N/A | N/A (IO link) |
| /dev/ttyS5 | N/A | SERIAL5 (NSH console) |
| /dev/ttyS6 | N/A | SERIAL4 |
