Interfacing SIM900A GSM Modem with Raspberry Pi

Interfacing SIM900A GSM Modem with Raspberry Pi

gsm_phone.py

import serial

import time

ser = serial.Serial('/dev/ttyUSB0',9600,timeout=1)

# 9600 is the default Baudrate for SIM900A modem

ser.flush()

ser.write('ATD9020XXXXXX;\r')

# AT command to call a number using GSM Modem

#ser.read(2)

# read 2 bytes of data from the serial port

time.sleep(10)

# wait for 10 seconds

ser.write('ATH\r')

# Hold the call

ser.close()

# close the serial port

connect RXD of USB2Serial to TXD of GSM Modem and TXD of Serial to RXD of GSM Modem. Also check if you can make a call to the modem and see whether a ring sound, so that network connection can be ensured.

You may use AT+CMGS=”phonenumber” for the sms