The need

My wife wanted to start her own seeds this year but here in Maine, you have to do that inside and also make sure you keep the right temperature during the day and night. #RaspberryPiToTheRescue !!

Took a bunch of scrap pieces of wood that I had to make the bench itself so it doesn’t look pretty but it works. We just covered it with some painter’s drop-cloths to hold the heat.

The build

Used a Raspberry Pi Zero (non-wifi) for this. I just gave it a USB Wifi adapter. Using the DHT11 for the temperature and humidity along with a 5v/110ac relay to turn and off a heat lamp as needed. Nothing fancy but it gets the job done. =) The icing on the cake is since I’m using NodeJS Express, I have a little web page so you can see the current status of the data. I did add in some logging to a CSV file so you can track how long the lamp is on/off along with the temp and humidity. Kind of cool data if you’re into that sort of thing.

The Code

You can view the GitHub repo here. Let me know if you have any questions. I might be making some more tweaks but should work as is. If you do make your own version, don’t be afraid to share it!

Pictures