cell

Python 2.7 code to interface a cheap 2G SIM800L to a cheap Raspberry Pi Zero W v1.1

License

• MIT

Parts

• Get a Raspberry Pi Zero W at Micro Center for $10 in-store pickup.

• Get a SIM800L on eBay for about $10 w/ free shipping:

• Get a free 1M/month SIM card from hologram

OS

• Using Raspbian Jessie version 2017-0705 found at Raspberry Pi Downloads

• After flashing the Raspbian to an SD card

  • Edit the /boot/command.txt and /boot/cmdline.txt files to enable the UART on the Pi Zero's GP14 (TX) and GP15 (RX)
  • Look at my files here in the repo to see the edits I made

Activate

• If you're using the free hologram.io SIM card (and if not, why not?), activate the SIM and choose the Developer Data Plan

Connections

• Hook up the SIM800 to the Pi Zero with a few wires:

SIM800 Pin	Pi Zero Pin
5V	Pin 2 - 5V
GND	Pin 6 - GND
VDD	Pin 4 - 5V
TX	Pin 10 - GPIO15 - RX
RX	Pin 8 - GPIO14 - TX
GND	Pin 14 - GND
RST	Pin -

• Insert your SIM card into the SIM800

Check It Out

• Install picocom to test connectivity sudo apt-get install picocom

• Start picocom picocom --baud 9600 /dev/ttyAMA0

• See if SIM800 is alive with the 'AT' command. The SIM800 should respond with 'OK'

• Read the SIM800 reference files in the repo's doc folder for many commands

Running with the Python Code

• The version of Raspbian I used comes with Python 2.7.9 so that's the version I have targeted with this code.

• Install psSerial (this installed v3.4 for me)

  • sudo pip install pySerial

  • pySerial has decent docs

• Install Pmw (this installed v2.01)

  • sudo pip install Pmw

  • Pmw is a toolkit for building a UI in Python using the Tkinter module. You can find docs at the Pmw Site

    • But the more recent v2 docs seem to be only provided in the tar.gz that you can download [here(https://sourceforge.net/projects/pmw/files/Pmw2)

• Run the cobbled code:

  • python cellComms.py

• Open the serial port with the Open button

• Send an 'AT' command with the AT button

• Get the SIM card IMEI with the IMEI button

  • This sends an 'AT+GSN'

• Get the SIM800 module version with the SIM800 button

  • This sends an 'AT+CGMR'

• Get the signal strength in bars with Bars button

  • This sends an 'AT+CSQ'

• Set the APN with the APN button

  • This button sends an 'AT+CSST=hologram'
    • I've hard coded my APN to hologram since that's the SIM card I'm using
    • Edit the APN constant in the code to change to whatever you're using

• Get the Network status with the Net button

  • This sends an 'AT+CREG'

LILYGO T-SIM7000G

LILYGO® TTGO T-SIM7000G SIM Development Board ESP32 Wireless Module WiFi Bluetooth GPS Antenna Support Expansion Solar Charge

Random Nerd - Getting Started with LILYGO T-SIM7000G ESP32 (LTE, GPRS, and GPS)

Buy at AliExpress