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.
Pinouts
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 |
Specifications
- 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
Resources
-
Adafruit FONA library: https://github.com/adafruit/Adafruit_FONA
- HamShield Integration Guide
- Repeater Integration Guide