<p>10 cm would be fine. That's the short answer, the real answer is that it depends on the UART speed and the exact conditions that you will be extending them. If you expect noise feedback from the motor coils inducing voltages into the UART lines, then perhaps they should be shorter. Keep the high current wires and the signal (UART) in separate places if possible. Also if you can use a shielded cable (e.g. and old shielded USB cable) then you could get away with a meter thereabout.</p>

CC BY-SA 4.0
2020-10-19T19:11:34.890Z
Should the shielding go to the negative rail of the controller board, or to a separate earth ground? I have both. The idea of USB cables is good, I have plenty of them. I could use one cable for STEP/UART one for DIR/ENABLE, and leave only motor and electronics power outside. I guess that DIR/ENABLE would not need shielding but it shouldn't hurt.
FarO
CC BY-SA 4.0
2020-10-19T19:22:11.900Z
Yes, the shielding should go to what you are calling the negative rail (otherwise known as GND). DIR/ENABLE are just logic signals so yes they should be fine.
user77232
CC BY-SA 4.0
2020-10-20T11:01:13.130Z
Even a few meters should be just fine. I believe Marlin uses 115200 to communicate with UART drivers.
towe
CC BY-SA 4.0
2020-10-19T18:59:49.647Z
2020-10-19T21:10:25.890Z
2020-10-19T21:10:25.890Z
user77232
<p>I would like to place the TMC drivers (the stepsticks modules, in fact) on the side of my controller board for easier cooling.</p>
<p>What is the maximum length of the data wires? Specifically, Step and UART, the other ones should not pose any problem.</p>
<p>In my case I would extend them by about 10 cm.</p>

<wiring><tmc2208>
What is the maximum length of the TMC drivers signal wires?
FarO
# What is the maximum length of the TMC drivers signal wires?

(Asked by: username_0 on 2020-10-19)

I would like to place the TMC drivers (the stepsticks modules, in fact) on the side of my controller board for easier cooling.

What is the maximum length of the data wires? Specifically, Step and UART, the other ones should not pose any problem.

In my case I would extend them by about 10 cm.

**Tags:** wiring, tmc2208

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## 1 answers

### Answer by username_1 on 2020-10-19. Score: 2 | Accepted answer

10 cm would be fine. That's the short answer, the real answer is that it depends on the UART speed and the exact conditions that you will be extending them. If you expect noise feedback from the motor coils inducing voltages into the UART lines, then perhaps they should be shorter. Keep the high current wires and the signal (UART) in separate places if possible. Also if you can use a shielded cable (e.g. and old shielded USB cable) then you could get away with a meter thereabout.

> **Comments:**
> **username_0**: Should the shielding go to the negative rail of the controller board, or to a separate earth ground? I have both. The idea of USB cables is good, I have plenty of them. I could use one cable for STEP/UART one for DIR/ENABLE, and leave only motor and electronics power outside. I guess that DIR/ENABLE would not need shielding but it shouldn't hurt.  
> **username_1**: Yes, the shielding should go to what you are calling the negative rail (otherwise known as GND). DIR/ENABLE are just logic signals so yes they should be fine.  
> **username_2**: Even a few meters should be just fine. I believe Marlin uses 115200 to communicate with UART drivers.  

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