Hi I am looking for a UV Sensor that shows current intensity and accumulated light over time. Does anyone have any suggestions? I was looking at: Grove - UV Sensor, ML8511 and VEML6070.
hi, i'm making something similar to yours, i know a lot of time has elapsed, but i'll input my knowledge. For your problem it has to do with how the data you are collecting is saved and the configuration for taking measurements you are using.
You probably are using a pull measurement, instead of constant measurement. So the device will give you the data saved in register, before taking a new measurement. For example if you take a measure every 1hour, without turning off, it will give you the measurement of the preview hour each time you request for data. This is common in a lot of systems with registers.
So your problem may be that when you turn on the device, there is garbage on the register. Thats why you have to do 2 measurements to get the actual value.
The library which @tomkxy posted works great for 8mhz processors. I have let it run for more than 24 hours without receiving a single timeout or checksum failure.
@janerik I'm not sure what you mean by "a CC110x module without RF stage", as the CC110x is the RF part (for panstamps as well as other systems). Do you only use the driver or do you use panstamp HW as well ? Do you use SWAP ? I've been using panstamps with SWAP for more than 5 years now, indor but in a humid environment (pool), and I didn't notice this. My DHT22 sensor (on "sensor" board, going 6 month with a single AA cell !) stopped measuring humidity a few months ago, but the board (and the temp part) is still working without any hiccup.
i use 2cell 7.4 volt recycled laptop battery packs for my projects thay have a natural discharge of 5% a month but do some reading and research on how to handle and charge them...and you should be fine..plus recycleing lappy batterys is good for the enviroment..and you also learn about the new breed of batterys and cells
