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
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
