Code: https://github.com/liutyi/elecrow-watering-kit-2-li/blob/master/watering-kit-hw2_1.ino
Upload using another Arduino: https://www.arduino.cc/en/tutorial/arduinoISP
Code: https://github.com/liutyi/elecrow-watering-kit-2-li/blob/master/watering-kit-hw2_1.ino
Upload using another Arduino: https://www.arduino.cc/en/tutorial/arduinoISP