To build an autonomous weather sensor I build an IoT node powered by a solar cell.
The following components were used:
- NodeMCU V2 Module with customized firmware (http://nodemcu-build.com/)
- Digital temperature and humidity sensor AM2315
- 2W Solar Panel 80X180 (SKU: 313070003)
- LiPo Battery Charger LiPo Rider Pro (SKU: 106990008)
- Battery-LIPO 1400 mAh
To reduce the power consumption the AM2315 sensor will be queried all 5 minutes only. The battery voltage is observed too, to get an indication for the battery condition.
The data will be sent to Thingspeak.com and can be seen calling this URL. Here is a snapshot from the morning of 04/13/2016.
An alternative website with integrated diagrams by iframes is here.
You will find the application program am2315_node.lua at Sourceforge and Github. I used a customized firmware for NodeMCU from master branch. The dev branch has AM2320 support included but I had problems within startup and went back to the master branch. Therefore the separate AM2315 module am2315.lua is required.