UART data transfer protocol

[WbCody]

I am connecting an ESP32 with a FPGA (Digilent Cmod A7). The data transfer will be bi-directional using the UART at 115200. The ESP32 is sending a single byte to the Cmod A7 using a Serial2.write(val). Where val == 'a' (ie 10101010). I am writing the FPGA driver to send and receive data from the ESP32.

Looking at the ESP32 TX pin using a logic analyzer; the ESP32 does not send out a single byte, instead it sends a series of bytes and it seems the 'a' is buried somewhere in these series of bytes communication.

Does anyone know the ESP32 external UART transaction protocol for both sending and receiving data?

Many thanks

[WbCody]

Ah, turns out there was some write to the UART in another of the code that I was unaware. A single character really does transmit as advertised in 10 characters.

Sorry for any inconvenience.