Who's got the best coverage map? Anyone using the Iridium satellite constellation, that's who. How does whole Earth coverage sound? Summit of K2 to summit of Everest? Check. South pole to North pole? Super check. In the animated image above, red is good. Check that coverage at the poles!
So how do you use the Iridium satellites? Similar to cellphones, you need to purchase both hardware and service, and there are various options out there. In this guide we will show you how to setup and use the Rock Seven RockBLOCK 9603 Iridium Satellite Modem. This hardware is tied to service that is also provided by Rock Seven.
We also have a CircuitPython library that provides an easy way to transmit messages from any CircuitPython board with an available UART.