Need help in setting up bidirectional communication between STM32F103C and ESP8266

[its-nott-me]

I’m working on a project that requires bidirectional communication between daisy-chained STM32F103C bluepill boards and an ESP8266. I’m using a master-slave architecture and UART for initial testing and prototyping. The chain has 3–6 STM32 boards.

Right now I’m having trouble getting reliable two-way data transfer between the ESP8266 (master) and the STM32 boards (slaves). Can anyone help me get this working? 

[TDK]

Here are multiple examples for UART on the STM32F1 series.

https://github.com/STMicroelectronics/STM32CubeF1/tree/master/Projects/STM32F103RB-Nucleo/Examples/UART

Get one of these working, then use it as a code base for your own project.