Unofficial Nextion/TJC User Forum

COM Port Proxy (for Nextion/MCU development/debugging)

I just realized that this tool I made might be helpful for people in here. I use it frequently when working with MCUs and Nextion panels.

By using my tool I keep both the MCU and Nextion panel connected to separate COM-ports on my PC. This way I can program them separately and when I want them to communicate, I just connect them through the proxy tool. It’s also possible to inspect all the communication between the MCU and the Nextion. I find it extremely useful for debugging.


Video example for data inspection:

Open source on GitHub of course:


This looks super handy. It should make switching in the Nextion Simulator easy too! Adding this to my toolset for sure, thanks for sharing this @hag!

1 Like

Gracias por el aporte, la idea es genial, y seguro que la utilizare.

Estoy encantado con este foro, por fin un lugar donde poder discutir sobre Nextion con tranquilidad y sin miedo. Sigan asi.


Hi…a friend of mine and I have been looking to use these in our IT projects for some time – and while a serial interface is great, it isn’t much use if you just want to stick a thermostat control on a wall 2 rooms away from where your controller is.

Not sure how this message relates to the topic? :thinking:

Hag, how much latency is there via your tool?

ie; have you compared incoming data to the Nextion (hardwired direct vs via your tool) with a DSO by any chance?
You could use a spare I/O port on the MCU to trigger the capture.

Hi @Flatpack2, I was sure I responded to this message, but I guess I forgot :laughing:

I haven’t checked the latency, but feel free to do some testing if you want. The tool is only intended to be used for testing/debugging/development where some extra latency is tolerable.

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