Simple 3 wire serial connection from PI3 to SKR V1.3 board

This is great thanks you! I'm still having issues getting it to connect but I'm closer :slight_smile:

Thank you Paco!!! Much appreciated.

Still having trouble getting a successful connection...

Has anyone else had luck? I have followed the steps a dozen times at this point and feel like i have to be missing something. Basically, everything is up and running but OctoPrint will not connect I have tried /dev/ttyAMA0 and /dev/serial0 everything else in the PI is set correctly and I have checked the connections. Any other tips? Could the SKR be disabling those pins somehow?

Any other advice would be appreciated I really want to get this going :slight_smile:

I think I'm getting closer...

I can now get OctoPrint to receive but it never gets an ok status...

Recv: T:23.75 /0.00 B:23.75 /0.00 @:0 B@:0

Just keeps listing these forever.

Did you also do...


And disable the getty service?

sudo systemctl stop serial-getty@ttyS0.service
sudo systemctl disable serial-getty@ttyS0.service

@ OutsourcedGuru and others.

My Pi failed yesterday out of the blue so I had to flash a new Octopi to the card.
So I had to perform the same staps again to get serial communication with three wires.

I performed the same steps as before but did not did the steps mentioned by Outsourced.
No serial connection where it worked before fine.
So I performed the mentioned extra steps.
Did you also do...


And disable the getty service?

sudo systemctl stop serial-getty@ttyS0.service
sudo systemctl disable serial-getty@ttyS0.service

And BINGO it works.

I will next week try and other SD card and try again if the last three steps are needed.

So if your connection is currently not working give it a try again.

Happy melting plastic.

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Not wanting to necro an old post but I need what is probably a very simple question answered.

Where are these three pins located on the SKR 1.3?

I see 2 sets of pins with those designations one is on the TFT header and the other the AUX1 header, which of these are you supposed to use?

Use the middle three of the TFT header, or the Gnd/Tx/Rx of the AUX header ... they're all connected so whatever is easiest.

Is there any reason I can't wire the 4 TFT ports on an SKR 1.3 straight to ports 4-10 on a Pi 3?

The TFT ports on an SKR 1.3 are +5V/GND/TX0/RX0 and ports 4-10 on a Pi3 are...5V/GND/TXD0/RXD0? It seems like this port on the SKR1.3 was made to both power and communicate with a Pi via a single connection?

Hi @illuminerdi!

Have you switched the RX/TX lines?

I haven't even tried it yet because I don't know if it will fry something or not...

switching tx rx will not fry anything.

I meant hooking the Pi's 5V pin to the 5V pin of the TFT port on the SKR 1.3. Seems like it should work but IDK...

Mostly it's that I haven't found someone somewhere that says "YES, this works and I have done it" and I don't really feel like risking both my Pi and SKR all to make one connection slightly easier

If the SKR can deliver the additional 2.5A at that port that the Pi needs (should be found in the documents).
The cable than should have devices to surppress electrical noise on the voltage.

I hope you mean "pins" or "wires" there rather than four distinct TFT displays.

  • 4 = 5V
  • 6 = Gnd
  • 8 = Tx
  • 10 = Rx

Should be able to. Just disable Bluetooth (or push it to the cheap UART), disable the console's use of the UART and enable the UART. Oh, and you want the Tx from one side of the communication to land at Rx on the other, and vice versa.

Yeah pins. IDK how ports got there. Autocorrect fail?

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Do you still need to Swapping ports used by GPIO and Bluetooth on a Raspberry pi 4B? Or does swapping the ports used by GPIO and Bluetooth chip is only needed for raspberry pi 3B+?

Like the 3B and earlier, the 4B still has two UARTs: one good and one not-so-good. Anytime you're trying to connect serial over GPIO pins then you need to play games with the configuration, as suggested.

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Cant for the life of me to get this work despite trying everything.
Only difference is I'm running an SKR 1.4

Would this work on a pi2 if i omitted the bluetooth part?
Thanks in advance