I found the inspiration for this project in the book "Open Source Lab" (https://www.elsevier.com/books/open-source-lab/pearce/978-0-12-410462-4) from Joshua M. Pearce (chapter 4.5). I found this project very interesting, but as an engineer, I thought I could improve some elements to make it more precise and smooth. It was, in fact, just a pretext to hack more technology.
I decided to replace the fridge by a peltier cooler, which can, if power supply is reverted, produce heat. This design was, in my humble opinion, a lot better than using resistors, although in practice, the control firmware in the arduino was hard to calibrate because of thermal inertia of the peltier system. I prefer to go at a slow pace rather than always reversing the current and generate a lot of waste heat.
For dehumidification, they were using rechargeable dehumidifiers with a fan blowing air on it (or not). I wanted to go with an electronic device and I found a mini adorable peltier dehumidifer. The only drawback is that it produces heat... I needed to use a bit of hacking programming skills to produce a stable temperature and humidity control knowing that condensation happened too in the cooling phase of the cooler (onto the peltier heatsink) and that the dehumidifier produces heat.