It would be nice if the SDIO pins were defined for this variant like other variants. A pinout diagram is here. I think this is the correct definition. // SDIO #define PIN_SD_CLK (18u) #define ...

Power Supply (x1): 5V–12V DC adapter for powering the Arduino, or in my case, we use 2S Lithium-ion battery connecting to Vin pin. Below you can see the circuit diagram used in the RFID-based ...

Place the SIM800L library folder into your \Documents\Arduino\libraries folder. You may need to create the libraries subfolder if its your first library. Restart the ...