# GPIO UART serial communication scrambled data

**URL:** <https://forums.developer.nvidia.com/t/gpio-uart-serial-communication-scrambled-data/157583>\
**Category:** Jetson Nano\
**Tags:** board-design, gpio, uart\
**Created:** [October 21, 2020, 5:11am UTC](https://forums.developer.nvidia.com/t/gpio-uart-serial-communication-scrambled-data/157583 "2020-10-21T05:11:21Z")\
**Posts on this page:** 1\
**Showing post:** 4

<div class="post-metadata">

**Author:** ![yurikleb](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/yurikleb/32/28901_2.png) [@yurikleb](https://forums.developer.nvidia.com/u/yurikleb)\
**Post date:** [October 21, 2020, 10:44am UTC](https://forums.developer.nvidia.com/t/gpio-uart-serial-communication-scrambled-data/157583/4 "2020-10-21T10:44:20Z")

</div>

Hello Jerry,

I can confirm the baud-rate setting in minicom is 115200/8n1.  
I just did another experiment with an Arduino Uno flashed with GRBL on it.

When connected via USB to the Jetson Nano, it shows up on /dev/ttyACM0  
and the serial communication (via minicom and the Arduino IDE serial monitor) works well.  
Here is a sample of an incoming data stream from the Arduino (GRBL Settings):

```auto
Grbl 0.9j ['$' for help]                                                     
['$H'|'$X' to unlock]                                                        
$0=10 (step pulse, usec)                
$1=25 (step idle delay, msec)           
$2=0 (step port invert mask:00000000)   
$3=1 (dir port invert mask:00000001)    
...

```

However when I connect the Arduino to the TX/RX pins of the Jetson Nano:  
Pin 6 for ground and pins 8,10 for the UART the Arduino appears on port /dev/ttyTHS1 and the incoming data is corrupt:

```auto
Grbl 0.9⸮⸮⸮⸮⸮⸮K⸮⸮⸮⸮⸮u5)mH'|'$X' t⸮⸮]⸮⸮kk⸮դ⸮$0=10 (st⸮⸮⸮[⸮	͕⸮⸮ (step i[X^KH[⸮֩H⸮I⸮B⸮ѕ⸮⸮⸮⸮⸮vert mask⸮⸮⸮JC!⸮S⸮B"⸮Ɂ⸮⸮⸮ѥ⸮⸮ert mask:LJC!S⸮B⸮ѕ⸮⸮⸮⸮⸮⸮⸮⸮nvert, bJC!RS⸮Bb⸮⸮⸮с⸮⸮⸮́⸮vert, bo⸮S⸮B⸮ɽ⸮⸮⸮⸮⸮⸮⸮⸮vert, boo⸮CS⸮B⸮х⸮⸮́ɕ⸮⸮⸮t mask:00⸮⸮⸮LLJCS⸮r⸮⸮⸮BRչ⸮ѥ⸮⸮⸮⸮⸮iation, mS⸮r⸮⸮⸮B
ɍ⸮ѽ⸮⸮Ʌ⸮⸮, mm)
$1⸮⸮⸮\Kс⸮⸮⸮⸮⸮ͱool)
$20⸮⸮⸮⸮ˋ⸮⸮⸮⸮⸮⸮ͱ⸮ol)
$21=⸮⸮⸮+⸮+ͱ⸮⸮⸮⸮⸮⸮22=1 (hom⸮⸮⸮⸮⸮⸮⸮⸮⸮⸮
$23=0 (h⸮[+K⸮⸮⸮ٕ⸮с⸮⸮k:0000000⸮⸮CS⸮⸮⸮r⸮⸮⸮B⸮⸮⸮⸮⸮⸮⸮⸮⸮⸮⸮Y mm/min)
MOML⸮⸮BB⸮⸮⸮⸮⸮⸮͕⸮⸮Q mm/min)
⸮⸮	⸮+⸮⸮⸮չ⸮⸮⸮͕⸮
...

```

The same setup on a Jetson Xavier NX results with a coherent serial data stream

Here is a photo of my wiring;

 ![PXL_20201021_105438852](https://global.discourse-cdn.com/nvidia/original/3X/9/3/937e43b8a2622e3b626c8c89b4a1fb80e2771821.jpeg)

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