# Serial communication usb

**URL:** <https://www.thethingsnetwork.org/forum/t/serial-communication-usb/34812>\
**Category:** Pycom\
**Created:** [February 25, 2020, 10:39am UTC](https://www.thethingsnetwork.org/forum/t/serial-communication-usb/34812 "2020-02-25T10:39:00Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![fekher\_khelifi\_omons](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/fekher_khelifi_omons/32/35697_2.png) [@fekher\_khelifi\_omons](https://www.thethingsnetwork.org/forum/u/fekher_khelifi_omons)\
**Post date:** [February 25, 2020, 10:39am UTC](https://www.thethingsnetwork.org/forum/t/serial-communication-usb/34812/1 "2020-02-25T10:39:00Z")

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I do serial communication (usb) between an rpi3 and a lopy, the problem is that the TTN does not receive the same byte transmitted by rpi3

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**Author:** ![arjanvanb](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/arjanvanb/32/46626_2.png) [@arjanvanb](https://www.thethingsnetwork.org/forum/u/arjanvanb)\
**Post date:** [February 25, 2020, 11:50am UTC](https://www.thethingsnetwork.org/forum/t/serial-communication-usb/34812/2 "2020-02-25T11:50:09Z")

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The payload `5B4E6F6E655D` [decodes to](https://www.rapidtables.com/convert/number/hex-to-ascii.html) the ASCII text `[None]`.

So, the screenshot that prints some debug info is not printing what you’re sending. Lacking any detail, that’s all we can tell from the screenshot.

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**Author:** ![LoRaTracker](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/loratracker/32/48502_2.png) [@LoRaTracker](https://www.thethingsnetwork.org/forum/u/LoRaTracker)\
**Post date:** [February 25, 2020, 12:23pm UTC](https://www.thethingsnetwork.org/forum/t/serial-communication-usb/34812/3 "2020-02-25T12:23:26Z")

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A packet every 3 seconds ?