ESP32 GPS tracker via wifi with cellular backup

[TrevorNoah]

I have a robot that I want to track around my yard posting position to a dashboard. Most of the time it should stay within WIFI range but I wanted to have a cellular backup in case it wanders off or is stolen. I couldn't find any examples of how to manage multiple internet connections and failover to cellular so I kludged together this example in case anyone finds it useful in the future. Hardware is an ESP32 (lolin32 i think) and a Simcom SIM7000A Cat M1 LTE modem with integral GPS chip.