Right now I have the following on a breadboard (see [1] for the illustrated version)
* ATTiny84
* DHT22 temp/humidity sensor
* 433 MHz TX module
* 3 x AAA batteries
* LED used for signalling (like booting up)
Initially I was using an Arduino Nano, but I couldn't optimize it enough so that it can live only on batteries, so I went with the ATTiny which is pretty impressive.
My oldest sensor node has been running for over 6 months on the same batteries and it still has some juice left (3.9V currently, it should work until it gets below 3.7V)
After I've settled with a final design I'm planning to solder it on a perfboard.
The DHT22 sensor accuracy is my only issue left, specifically the humidity measurement part (see [2] for some extensive research by someone smarter than me).
Everything is on github[3] but it's pretty messy at the moment (hardcoded and such) because there's never enough time for everything.
emilburzo|9 years ago
* ATTiny84
* DHT22 temp/humidity sensor
* 433 MHz TX module
* 3 x AAA batteries
* LED used for signalling (like booting up)
Initially I was using an Arduino Nano, but I couldn't optimize it enough so that it can live only on batteries, so I went with the ATTiny which is pretty impressive.
My oldest sensor node has been running for over 6 months on the same batteries and it still has some juice left (3.9V currently, it should work until it gets below 3.7V)
After I've settled with a final design I'm planning to solder it on a perfboard.
The DHT22 sensor accuracy is my only issue left, specifically the humidity measurement part (see [2] for some extensive research by someone smarter than me).
Everything is on github[3] but it's pretty messy at the moment (hardcoded and such) because there's never enough time for everything.
[1] - https://raw.githubusercontent.com/ambient-monitoring/node/ma...
[2] - http://www.kandrsmith.org/RJS/Misc/Hygrometers/calib_dht22.h...
[3] - https://github.com/ambient-monitoring