Hello,
I have developed similar device. This device collects data from Solar Inverter using RS232/RS485 based MODBUS protocol and send collected data to server using GSM/GPRS.
In your case it will send data using WiFi.
Relevant Skills: MODBUS RTU/TCP-IP, RS232/RS485, WiFi, BLE, GSM/GPRS, Offline storage, Logging.
Softwares: EAGLE, Altium, ORKAD.