there are photos here, the code runs on a STM32blackpill board using stmduino. you will need to lookup the pinout for the board to see what pins are for the serial ports .
I believe A0 is for the position feedback, it connects to the signal out on the servos potentiometer, A1 is for the servo PWM output and the flight controller connects to uart 1 and the sonar to uart 2.
