I was curious to see how many 1-wire DS18B20 sensors Cayenne could automatically discover. To my delightful surprise, 9 DS18B20 sensors were automatically discovered, without me having to add a single widget. Total time: ~ 20 mins. With the majority of time spent wiring each DS18B20. Unfortunately I ran out of additional DS18B20 to connect…I’ll have to update this post when I exceed 9. Thanks for checking this project out!
Overview
I used the web dashboard for adding the DS18B20, but the widgets also appeared in the app.
I used two types of DS18B20, 5 normal sensors and 4 waterproof coils. I used a 4.7K resistor for each DS18B20.
Each DS18B20 is connected to GPIO Pin 4. I used a small breadboard to connect each sensor to GPIO Pin 4.
I installed Cayenne, powered my Pi off, connected the 5 normal sensors, powered my Pi back on, and verified that all 5 DS18B20 automatically appeared on the dashboard. (Had to wait a few seconds).
I then powered my Pi off again, connected the remaining 4 DS18B20 waterproof coils, powered my Pi back on, and the remaining 4 DS18B20 waterproof temperature coils appeared in my dashboard.
Interesting to see the variation of temperature between each sensor.
It’s a DS18B array, get a small LED torch ans shine it in close up to the middle, centre will be hotter and fad out near the edges and corners. Voila, demonstration of CCD or pixel array (as such ;-)).
If you can get the display to be the same as the 7x8 matrix you have, even better.
