HATs and other add-ons • Re: GSM/GPRS/ SIM868 not worked

Code:

"""Raspberry Pi Pico (MicroPython) exercise:work with SIM868 GSM/GPRS/GNSS Module"""import machineimport osimport utimeimport binascii# using pin definedled_pin = 25  # onboard ledpwr_en = 14  # pin to control the power of the moduleuart_port = 0uart_baute = 115200APN = "CMNET"reading = 0temperature = 0# uart settinguart = machine.UART(uart_port, uart_baute)print(os.uname())# LED indicator on Raspberry Pi Picoled_onboard = machine.Pin(led_pin, machine.Pin.OUT)# MQTT Server infomqtt_host = '47.89.22.46'mqtt_port = '1883'mqtt_topic1 = 'testtopic'mqtt_topic2 = 'testtopic/led'mqtt_topic3 = 'testtopic/temp'mqtt_topic4 = 'testtopic/adc'mqtt_topic5 = 'testtopic/tempwarning'mqtt_topic6 = 'testtopic/warning'mqtt_topic7 = 'testtopic/gpsinfo'mqtt_msg = 'on'def led_blink():    led_onboard.value(1)    utime.sleep(1)    led_onboard.value(0)    utime.sleep(1)    led_onboard.value(1)    utime.sleep(1)    led_onboard.value(0)# power on/off the moduledef power_on_off():    pwr_key = machine.Pin(pwr_en, machine.Pin.OUT)    pwr_key.value(1)    utime.sleep(2)    pwr_key.value(0)def hexstr_to_str(hex_str):    hex_data = hex_str.encode('utf-8')    str_bin = binascii.unhexlify(hex_data)    return str_bin.decode('utf-8')def str_to_hexstr(string):    str_bin = string.encode('utf-8')    return binascii.hexlify(str_bin).decode('utf-8')def wait_resp_info(timeout=2000):    prvmills = utime.ticks_ms()    info = b""    while (utime.ticks_ms()-prvmills) < timeout:        if uart.any():            info = b"".join([info, uart.read(1)])    print(info.decode())    return info# Send AT commanddef send_at(cmd, back, timeout=2000):    rec_buff = b''    uart.write((cmd+'\r\n').encode())    prvmills = utime.ticks_ms()    while (utime.ticks_ms()-prvmills) < timeout:        if uart.any():            rec_buff = b"".join([rec_buff, uart.read(1)])    if rec_buff != '':        if back not in rec_buff.decode():            print(cmd + ' back:\t' + rec_buff.decode())            return 0        else:            print(rec_buff.decode())            return 1    else:        print(cmd + ' no responce')# Module startup detectiondef check_start():    while True:        # simcom module uart may be fool,so it is better to send much times when it starts.        uart.write(bytearray(b'ATE1\r\n'))        utime.sleep(2)        uart.write(bytearray(b'AT\r\n'))        rec_temp = wait_resp_info()        if 'OK' in rec_temp.decode():            print('SIM868 is ready\r\n' + rec_temp.decode())            break        else:            power_on_off()            print('SIM868 is starting up, please wait...\r\n')            utime.sleep(8)# Check the network statusdef check_network():    for i in range(1, 3):        if send_at("AT+CGREG?", "0,1") == 1:            print('SIM868 is online\r\n')            break        else:            print('SIM868 is offline, please wait...\r\n')            utime.sleep(5)            continue    send_at("AT+CPIN?", "OK")    send_at("AT+CSQ", "OK")    send_at("AT+COPS?", "OK")    send_at("AT+CGATT?", "OK")    send_at("AT+CGDCONT?", "OK")    send_at("AT+CSTT?", "OK")    send_at("AT+CSTT=\""+APN+"\"", "OK")    send_at("AT+CIICR", "OK")    send_at("AT+CIFSR", "OK")# Get the gps infodef get_gps_info():    count = 0    print('Start GPS session...')    send_at('AT+CGNSPWR=1', 'OK')    utime.sleep(2)    for i in range(1, 10):        uart.write(bytearray(b'AT+CGNSINF\r\n'))        rec_buff = wait_resp_info()        if ',,,,' in rec_buff.decode():            print('GPS is not ready')#            print(rec_buff.decode())            if i >= 9:                print('GPS positioning failed, please check the GPS antenna!\r\n')                send_at('AT+CGNSPWR=0', 'OK')            else:                utime.sleep(2)                continue        else:            if count <= 3:                count += 1                print('GPS info:')                print(rec_buff.decode())            else:                send_at('AT+CGNSPWR=0', 'OK')                break# Get the gps infodef phone_call(phone_num='10000', keep_time=10):    send_at('AT+CHFA=1', 'OK')    send_at('ATD'+phone_num+';', 'OK')    utime.sleep(keep_time)    send_at('AT+CHUP;', 'OK')# Bluetooth testdef bluetooth_test():    send_at('AT+BTPOWER=1', 'OK', 3000)    send_at('AT+BTHOST?', 'OK', 3000)    send_at('AT+BTSTATUS?', 'OK', 3000)    send_at('AT+BTSCAN=1,10', 'OK', 8000)    send_at('AT+BTPOWER=0', 'OK')# AT testdef at_test():    print("---------------------------SIM868 TEST---------------------------")    while True:        try:            command_input = str(input('Please input the AT command,press Ctrl+C to exit: '))            send_at(command_input, 'OK', 2000)        except KeyboardInterrupt:            print("\r\nExit AT command test!\n")            power_on_off()            print("Power off the module!\n")            break# main programcheck_start()get_gps_info()