How humid is my apartment right now? Let me text my FONA!
While smart-home applications like as Apple's HomeKit are great - they use a large amount of cellular data and take time to load information you may not care about. Instead of using a WiFi connection, an Adafruit FONA cellular module lets you obtain sensor readings from anywhere with cell reception.
In this guide, you will build a text-able environmental monitor using the Adafruit FONA shield, a Metro M0/M4 development board and a Bosch BME280 precision sensor. Using CircuitPython, the Feather can send and receive SMS messages using the CircuitPython FONA library and read environmental data from the BME280 sensor with the CircuitPython BME280 library.
Code with CircuitPython
CircuitPython is the easiest way to program an Internet of Things project. We've built a helper library, Adafruit_CircuitPython_FONA, to make interfacing with the FONA module's SMS capabilities incredibly simple.
The Adafruit FONA is an all-in-one cellular phone module that lets you add voice, cellar data, location-tracking (FONA-808 and FONA-3G only) and SMS to your project. The FONA shields fit right over shield-compatible CircuitPython boards.
On its own, this shield can't do anything. It requires a microcontroller like a Metro M4 or Metro M0 to drive it!
The Bosch BME280 precision sensor can measure humidity with ±3% accuracy, barometric pressure with ±1 hPa absolute accuracy, and temperature with ±1.0°C accuracy.
You will also need some required accessories to make the FONA work. These are not included with the FONA shield or breakout!
You will need a Mini SIM card to do anything on the cellular network.
If you're in the USA, we suggest picking up the 2G SIM Card from Ting.
- If you're not in the US, or want to use a different cellular network provider, please see this page for more information about obtaining a FONA-compatible SIM card.
You will need a LiPoly battery (500mAh or larger) to run the FONA module.
You will need a external uFL GSM Antenna, we like this slim sticker-type antenna:
If you want to use a SMA antenna instead, you'll want to pick up a uFL to SMA adapter cable.