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Re: Information on App developer projects
Posted: Mon Jan 19, 2026 6:51 am
by chipfryer27
Hi Bob
Most of the ESPs have used have three UARTs with 0 being the USB, which is handy for sending out debugging messages. Obviously if you have a terminal program using the port you need to disconnect before FC can program.
Nice layout.
Regards
Re: Information on App developer projects
Posted: Mon Jan 19, 2026 9:07 am
by RGV250
Hi,
Unfortunately I cannot take credit for the layout, it is a modified Environment monitor sample project.
Most of the ESPs have used have three UARTs with 0 being the USB
This is what I don't like about ESP, the closest schematic I have found is for the DevKit 1. It shows Tx/Rx0 on GPIO pins 1 & 3 and there is a comment saying they are excluded pins and used for serial programming. Also Tx/Rx2 on GPIO 16 &17, there is no mention of Tx/Rx1 and the comical thing is I am using GPIO 12 for Rx in from the monitor which causes the issue but FC says it is channel 2.
I am probably wrong but I regard ESP more as a toy than a serious tool. To support this I also have a DFRobot Fire Beetle 2 which states 2 UARTS and only shows 1 on the schematic.
Regards,
Bob
Re: Information on App developer projects
Posted: Mon Jan 19, 2026 9:54 am
by BenR
Hi Bob,
All three UARTs and in fact most peripherals on the ESP are remappable, the hardware peripheral pins can be moved around.
The only one that should be tacked down is the one that's used for programming and debugging which is usually UART0 - Channel1 in Flowcode.
We have a new tool available shortly in v11 which shows all the device pins and peripherals and highlights what is available where to make things like this much easier.
Here is the standard ESP32.

- Esp32Pins.jpg (92.34 KiB) Viewed 34 times
The caveat to this is the original ESP32 device has a few input only pins IO34-IO39. Later chips seem to have overcome this problem.

- Esp32PinsInputs.jpg (114.16 KiB) Viewed 18 times