We are excited to announce the successful testing of our SIM800 modem as a PPP link. The instructions are tested in the Ubuntu 16.04 version and will be straightforward to configure in other Linux OS variants. Again sorry windows users, we couldn't find any libraries for windows configuration. 

 

 

Note that we tried to simplify the instructions and trimmed the example for SIM800 module. But you can go through the man pages of the utilities used for more advanced configuration options. 

 

Install the required application using the following commands

sudo apt-get update

sudo apt-get install ppp

 

Now we want to configure the ppp interface to communicate with our GSM modem. This can be done using the following instructions

 

cd /etc/ppp/peers/

sudo nano rnet

 

Then include the following contents to the rnet file

 

###  File Begin  ###

#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/ttyUSB0

# 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

###  File End  ###

 

Special note: Here we assume that the modem can be communicated using ttyUSB0 interface and baudrate 115200. Please ensure this beforehand and then try the instructions in the blog post. 

 

Edit the following file if the SIM is protected by a PIN

nano /etc/chatscripts/gprs

 

Finally type the following command to activate the new interface

 sudo pon rnet   

 

At this point you will be noticing a fast blink rate of network led in our GSM module which represents the GPRS activity.

 

We can also deactivate the PPP interface if required using the following command

 sudo poff rnet 

 

You can purchase the GSM modem using the following link

https://www.elementzonline.com/gsm-gps-rf-wireless/sim800-gsm-modem-module-with-sma-antenna-rs232-ttl-and-usb--260

 

Original instructions can be found here. 

https://www.rhydolabz.com/wiki/?p=16325

 

We have created a simple installation script to make your linux system ready for PPP interface. This can be downloaded from the following link

 

https://gitlab.com/elementzonline/Arduino-Sample-Codes/tree/master/GSM_PPP_interface