Serial Communication Using Gsm Modem
Here we are with yet another post on our favorite Pi. We had many different posts on Raspberry Pi as well as on GSM-GPRS connectivity. So what do we have here new? What we discussed so far focused either on GSM connectivity or TCP/IP connection over GPRS, here we intend to tether our Raspberry Pi to the internet through a GPRS cellular data connection. Lets see how its done. Hardware Requirements • • • • 5v 1A power source (For GSM modem) Make the connections as shown in the figure above. Provide separate power source (5V 1A) to the GSM modem for proper functioning as it drives much current.
Insert a 2G activated SIM card, with working data connection, and power up the modules. It will take a few seconds for the SIM to get registered to the network. Now we need to check the communication between the RPi and the modem. For which, we make use of a python code that transmits an AT command and verifies whether an OK is received as acknowledgement. Open a python shell using sudo idle command and create a new file. Copy the code shown below, save and run the code.
We had many different posts on Raspberry Pi as well as on GSM-GPRS. A Node to Node communication using serial. Connecting the modem to Raspberry Pi. Serial Communication With Gsm Modem Sim900. To test this program you will need to connect your computer via serial cable and use a serial communications tool such. The post explains how to send SMS using GSM Modem and Arduino. It also consist of RS232 port for serial communication between the modem and computer. Serial GSM modem over TCP/IP. A very reliable way to use a serial GSM modem on a server that has no serial port is with a TCP/IP to RS232 convertor.
If you are new to Raspberry Pi, we suggest reading before you proceed. Print rcv Run the code and if the connections are all working good, then we will receive an OK acknowledgement in the python shell. PPP Configuration PPP or Point to Point Protocol establishes a Node to Node communication using serial interface. We make use of this, while accessing serial data connection on a PC. Here, using the serial connection, proper commands and PPP, we are about to access the internet on Pi. APN An Access Point Name (APN) is the name of a gateway between a GSM/GPRS network and the internet. The APN of the cellular network that we are using, must be know to us.
You can either ask it out on google or contact the service provider. In this example, we have used and for the APN we asked it on Google. Installation The first step is to disable the kernel’s use of the hardware serial connection. By default, when the Raspberry Pi boots, it will use the serial connection to produce messages from the kernel and it will confuse the GSM modem. Follow the steps below From Menu Select Preferences –>Raspberry Pi Configuration. In this window, Select the interfaces tab and disable the serial option. The next process is to install PPP Software.
Make a suitable internet connection on the RPi by means of an Ethernet cable or WiFi. Open the LX Terminal and type. #imis/internet is the apn for idea connection connect '/usr/sbin/chat -v -f /etc/chatscripts/gprs -T imis/internet' # For Raspberry Pi3 use /dev/ttyS0 as the communication port: /dev/ttyS0 # Baudrate 115200 # Assumes that your IP address is allocated dynamically by the ISP. Noipdefault # Try to get the name server addresses from the ISP.
Usepeerdns # Use this connection as the default route to the internet. Defaultroute # Makes PPPD 'dial again' when the connection is lost. Persist # Do not ask the remote to authenticate. Noauth # No hardware flow control on the serial link with GSM Modem nocrtscts # No modem control lines with GSM Modem local. Local From the above file, two parameters must be changed which depends on the modules used.
In the beginning command, connect, after the section -T, the APN of the service provider should be given. Here we have used the APN of Idea (imis/internet).
Then comes the communication port, as we have used Pi 3 in our exapmle, the port name is /dev/ttyS0. Savegame Installer V2 0 Homebrew Mac. Save the configuration file by pressing ctrl+x. This configuration file controls the options that will be set by PPPD, when the GSM Modem PPP connection is created. You can find a description of all the options in the.