I have the latest Solar Piston design running in an arduino compatible circuit that also has a WiFi module (RN-171), temp sensor (TCN75A), and a light sensor (APDS-9301). The arduino sketch updates every 5 min (supposedly) to my pachube feed. Right now I’m sending temp and voltage. The light sensor is not hooked up yet. I’m deriving voltage by analogReading the band-gap reference. The battery im starting with is NiMH, because it might still hold charge if it accidentally drains low. Link to code and schematics coming!
Here’s some pics
Graphs below show the last 24 hours. For different time scales, go here.