When you don't have a steady cellular signal or immediate Wi-Fi access but need to communicate with others around you, you can set up an off-the-grid voice communications network using a Raspberry Pi and an Android app. There are apps such as Bridgefy that will create a mesh network to communicate with other devices over Bluetooth. Still, when you're traveling in a convoy and want to message people in other vehicles, all the metal will make that nearly impossible. Even in situations where you...
