making a thermometer

For this 3rd challenge, I worked together with Gerda and Paula B. We wanted to make a thermometer for the solar ovens we are making for our Slow Lab project. Beyond just thermometers, the idea was to have a interface to follow "live updates" of the temperature on a screen and a way to collect this data from different "solar oven owners" on a platform on which anyone could upload their data, compare the efficiency of their ovens, share tips about the design...in a similar way as Smart Citizen Kit platform shares sensors data.

We split the work and I was mainly working on the electronics and programming part to program the output of "array" of LED (with a neopixel stripe) based on the temperature readings of our sensor. We started with a DHT11 that worked quite well but figured out that it couldn't reach very high temperatures so we had to change it for a thermistor that we had which are less precise. We added a potentiometer to calibrate the readings of the thermistor. I was nice to see that it become a bit quicker and easier than before to take the steps of wiring components, looking for a library, adapting the code...

For the digital interface, I worked on p5js which I connected to the ESP32 to display the temperature readings as well as a line showing the temperature evolution in time. It could really be improved and I would like to find a way to have it as an app rather than working only when connected to my computer as in a real use case I would not be next to the oven with my laptop. I didn't have time to work on the data collection for ad hoc analysis or upload on a platform so I will investigate on this outside of the challenge.

The context of this challenge was a little bit particular for us as we had an event to prepare for the Sunday as part of our design interventions so we were in parallel continuing to build an oven and a stereo system that we would power with 12V solar panels.

The details about the process and the files are available on our git repository here.