I've ordered a month ago a few Dallas DS18B20 one wire digital thermometer and a welded DHT11 (Hygrometer + Thermometer) from an eshop. When i started this project i forgot to buy some matrix boards so i took some really old broken boards (they were mostly old FM radio) and i have unwelded the components. After some PCB modifications i used the old board to weld the DS18B20 with a 4.7K resistor and 3 old cables got from an old (and broken) PC.
I took an old Liquorice metal box and i've isolated the components with the wire tape.
While i was searching for boards, i found an old mini engine for a model railway locomotive and welded it with 2 cables. My future plan for this engine is to use it as an Anemometer.
What's next? Well i found also a solar panel from a broken Chinese calculator (those given as gadgets in the fairs) and i've decided to use it to get the light intensity, but since i have also a photoresistor, i'll probably use both to check the light. The Anemometer (aka the engine) ,the solar panel and the photoresistor will be attached to a MCP3008 (an 8 channel ADC that i got for free).
|Photoresistor | MCP3008 | 3.3V Solar panel|
For now i've spent less then €2 (less then €1 for the DHT11, €1 for 2 DS18B20).
To test the components (for now) i've used my raspberry pi and my HD44780.