# UART over Serial

**URL:** <https://wled.discourse.group/t/uart-over-serial/15377>\
**Category:** Issues\
**Created:** [June 10, 2026, 7:44am UTC](https://wled.discourse.group/t/uart-over-serial/15377 "2026-06-10T07:44:13Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![nalianjo](https://avatars.discourse-cdn.com/v4/letter/n/919ad9/32.png) [@nalianjo](https://wled.discourse.group/u/nalianjo)\
**Post date:** [June 10, 2026, 7:44am UTC](https://wled.discourse.group/t/uart-over-serial/15377/1 "2026-06-10T07:44:13Z")

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I want to control animations on a esp32(S3) with WLED with another esp32-S3 over the serial Pins with UART. The problem is, that when I plug an USB-C cable in and sent commands they work fine, but WLED only watches the USB-C Serials, not the pins (RX/TX) on the esp itself. It seems that there is no way to change the serials not beeing the USB serials but GPIO 16/17 or GPIO 43/44. When the transmitter-esp sents commands, both esp even blink, but WLED just ignores them.

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**Author:** ![dedehai](https://yyz2.discourse-cdn.com/free1/user_avatar/wled.discourse.group/dedehai/32/7265_2.png) [@dedehai](https://wled.discourse.group/u/dedehai)\
**Post date:** [June 10, 2026, 7:58am UTC](https://wled.discourse.group/t/uart-over-serial/15377/2 "2026-06-10T07:58:28Z")

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Did you try disabling the usb uart? i.e. compile with  
-D ARDUINO\_USB\_CDC\_ON\_BOOT=0

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<div class="post-metadata">

**Author:** ![nalianjo](https://avatars.discourse-cdn.com/v4/letter/n/919ad9/32.png) [@nalianjo](https://wled.discourse.group/u/nalianjo)\
**Post date:** [June 10, 2026, 8:05am UTC](https://wled.discourse.group/t/uart-over-serial/15377/3 "2026-06-10T08:05:01Z")

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Where can I do that?

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**Author:** ![blazoncek](https://yyz2.discourse-cdn.com/free1/user_avatar/wled.discourse.group/blazoncek/32/1886_2.png) [@blazoncek](https://wled.discourse.group/u/blazoncek)\
**Post date:** [June 10, 2026, 11:51am UTC](https://wled.discourse.group/t/uart-over-serial/15377/4 "2026-06-10T11:51:56Z")

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You will need to replace Serial with Serial1 if you want to use both.

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**Author:** ![nalianjo](https://avatars.discourse-cdn.com/v4/letter/n/919ad9/32.png) [@nalianjo](https://wled.discourse.group/u/nalianjo)\
**Post date:** [June 10, 2026, 12:52pm UTC](https://wled.discourse.group/t/uart-over-serial/15377/5 "2026-06-10T12:52:12Z")

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in WLED there is no way to change any serials, and I don’t want to use more serials, I just want the serials in WLED to be 17/18 or 43/44 or any GPIO on the esp controller, just not the USB-Serial

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**Author:** ![blazoncek](https://yyz2.discourse-cdn.com/free1/user_avatar/wled.discourse.group/blazoncek/32/1886_2.png) [@blazoncek](https://wled.discourse.group/u/blazoncek)\
**Post date:** [June 10, 2026, 1:17pm UTC](https://wled.discourse.group/t/uart-over-serial/15377/6 "2026-06-10T13:17:34Z")

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Some devices have two serial interfaces: CDC and “regular” serial/UART. If ARDUINO\_USB\_CDC\_ON\_BOOT=1 then Serial represents CDC port and Serial1 represents “regular” UART in such case.

You _need_ to change source code for that to work.