Using the built-in GPS, ESP32 Gateway can obtain a fix on its current location and also acquire current time. This makes IoT asset tracking easier.
News and Updates on the ESP32 4G Gateway Gen.1 which features a 4G LTE modem, ethernet, RS485 and solar power with a battery charger.
ESP32 PPPoS modem “esp_modem_dte_send_cmd(): process command timeout” error, causes, and some solutions that work with SIM7600 and A7670.
Using multiple SIM cards with SIMCom or Quectel modems is easy using multiplexers and a basic logic controller. Modems must support hot swap.
I list some cases with using SIM commands like AT+CIMI which result in “ERROR: SIM failure”. Common problems are listed along with solutions.