T-Beam Meshtastic is a wireless module with ESP32, LoRa, GPS, WiFi, and Bluetooth capabilities. It features a 0.96-inch OLED display and supports various frequency bands including 433/868/915/923Mhz.
Google researchers demonstrated the ability to use GPS signal measurements from millions of anonymous Android mobile devices to map the ionosphere with high accuracy, potentially improving GPS navigation worldwide.
A blog post about a portable starmap project built using Arduino. The project includes a round LCD display, GPS module, and star chart data stored in a flash memory chip.