USART Interrupt STM32F103ZET6

Hello all.

I am new working with the SMT32 microcontrollers and I need your help.

The project deals with 3 communication channels USART to 19200bds (usart1, usart2 and usart3)

The microcontroller used is the STM32F103ZET6 and would be connected to 3 different computers by RS232.

The received data are of different length depending on the command sent.

I need an example of code that detects each data received by each different channel to save it in a reception buffer to process them and once analyzed the data to initialize the reception buffer again.

I need a code that detects the interruption of data received by the usart.

I await yours advice and help.

Thanks you very much.

Best regards