Serial connection between External Device and Pi CM4/CM5 on MANTA M8P

General Discussion
1

Hey, I was wondering if anyone could confirm that it is possible to achieve serial/UART communication between the Pi CM4/CM5 on the MANTA M8P and an external serial device with TX and RX pins. I was hoping I could be able to just connect the TX on the 40 pin GPIO of the Pi with the Rx of the device and vice versa but I keep running into connection issues such as “[TxRxResult] There is no status packet!”. I have ensured the device is also being powered and grounded while I try run the connection and checked I am using the correct serial port and baud rate. I was actually able to verify the external module device is in fact working as I was able to connect it to the Pi via the usb port on the MANTA. Hence, it seems like either there is something wrong with my Tx and RX pins or they are just not able to be used in this way on a MANTA board. I have also made sure to have the DIP switch set to OTG-USB in case that would affect anything but did not notice any change.

2

Hi @AlSabra ,

Please attach the requested klippy.log to your next post.

3

Hey,

I don’t have any logs in this instance as I’m not running Klipper for this. I was just wondering if the Pi board on the MANTA lets you achieve UART communication with external devices purely with the Pi.

4

Sure. The 40 pin rPi GPIO connector is available for your use.

Pins 8 & 10 are UART0 TX and UART0 RX, respectively.

5

Thanks for confirming Myke. I wonder why I’m running into issues I will need to keep troubleshooting then.