The latest is the TTGO T-Call, an ESP32 breakout board that also has a cellular modem. Yes, it’s only a 2G modem, but that still works in a lot of places, and the whole thing is $15. On board ...

This led him to design the Sailor Hat with ESP32 — a marine specific, open source hardware development board. The marine environment can be pretty harsh with extremes of temperature, rain ...