Content import os import display import utime def get_mac(): if 'mac.txt' in os.listdir("."): f = open('mac.txt', 'r') mac = f.read() f.close() return mac else: return '' def loop(): while True: mac = get_mac() with display.open() as disp: disp.clear() disp.print('battery v') disp.print(str(os.read_battery()), posy=22) if mac != '': print('print mac') disp.print('mac', posy=44) disp.print(mac, posy=66) disp.update() disp.close() utime.sleep(1) loop()