GSM Module for Autopatch and Data

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  • Regular price $ 5.99

Want to add cellular voice to your HamShield project for an auto-patch system?

Looking to use HamShield as an APRS iGate in a remote location, using GSM for data backhaul?

We have a great, low cost module for that.

Introducing the SIM800C GSM Module. It features a quad band radio, for use in most places in the world. Works on 850/900/1800/1900MHz.

The SIM800C is a 2G voice and EDGE module. Yes, I know what you are thinking. Does 2G still exist? You bet. 

In the United States, T-Mobile operates a robust 2G network for IoT. Internationally, it is still deployed and in heavy use for low cost connectivity projects.

the GSM module features an AT command set and built-in TCP/IP stack for establishing connections to the cloud, sending text messages, and making voice calls. 

For low cost service, we recommend Twilio. They work internationally, cost as little as $2 a month, with data rates as low as a few cents per megabyte. Leveraging the T-Mobile network, it also works almost anywhere in the world. 


Bank #1

 Pin Number Label Description
1 RING Ring indicator
2 DTR Data Terminal Ready
3 MICP Mic +
4 MICN Mic -
5 SPKRP Speaker +
6 SPKRN Speaker -


Bank #2

Pin Number
Label Description
1 NET Network indicator LED (sink)
2 VCC 3.3V-4.5V
3 RST Reset
4 RXD TTL Serial Receive
5 TXD TTL Serial Transmit
6 GND Ground



  • 2G GSM and GPRS/EDGE module
  • Built in TCP/IP stack
  • AT command support
  • Arduino compatible libraries, such as the Adafruit Fona library
  • Uses TTL Serial 
  • 3.3V-4.5V (Lithium battery voltage range)
  • Text-to-speech support

What it comes with

  • Optional loaded antenna
  • U.FL for cellular antenna
  • Header pins
  • GSM module