I’ve been trying to send simple data from the UnitV2 to the Raspberry Pi using UART on the ttyAMA0 port.

import serial
import time

#  M5Stack UnitV2
uart = serial.Serial('/dev/ttyAMA0', 115200) 

while True:
    uart.write(b'Hello from M5stack\n')
    time.sleep(1) 

While the Pi itself can successfully utilize ttyAMA0, the UnitV2 is unable to communicate through this port. Despite updating the firmware as recommended, I still can’t establish communication between the UnitV2 and Pi via UART.

#pi
import serial
import time

try:
    ser = serial.Serial('/dev/ttyAMA0', 115200, timeout=1)  
    print("Serial port opened successfully")
    ser.write(b'Hello from Raspberry Pi!\n')

    while True:
        if ser.in_waiting > 0: 
            data = ser.read(ser.in_waiting).decode('utf-8').strip()
            print(f'Received: {data}')
        time.sleep(1) 
except serial.SerialException as e:
    print(f'Error: {e}')
finally:
    ser.close()

Any advice on how to resolve this?

Thank you for your help.