Hi, I’m working with sensors in locations where there is no power and No Wi-Fi. 4G is available in some areas and I have used a 4G router to create a hotspot but it uses a lot of power from the battery. Sometimes I have to change the battery because the battery and / or solar panel are not big enough. Changing the battery is a hassle because it’s someone else’s property - I have to coordinate with them.
I think it would be OK to just store the readings on an SD card and an SD card reader costs like £1! I notice projects on the internet showing how to connect an SD card reader to an ESP8266 and also noticed the CSV checkbox in the sensor.community Airrohr configuration. Is it possible to just write the same data to an SD Card and retrieve it later? I’m not a programmer. Thanks.