For a while I develop ideas for measuring temp and humidity in my grow projects.
I seek for ways to do that, both analog and digital.
- There are circuits from the analog world with op amps and thermistors
- There are digital projects on Arduino and Raspberry Pi
I am a Raspberry Pi enthusiast and I found a book about how to measure temperature and humidity using a simple and cheap DHT11 sensor.
The project is mostly software based, of course the Raspberry Pi provides the necessary hardware.
To describe it briefly, the sensor sends digital data to a module suitable for that, the data is then stored in a databank.
A visual chart is generated either locally on the Pi. Or it is sent to a webpage using socket.io and Firebase, a cloud service on the internet.
After setting up a database and a generic webpage on Firebase, the data can be looked at from every place where internet is available.
I use it for monitoring my cacti that will stay on the outside for the whole winter.
Before that I installed a heating system that has its own temperature sensor and it switches a heating coil when temp goes below 37.4 F.
But this cost me 70 EUR so I installed an additional DIY system with a time switch for my other grow table.
It is only a matter of time and my motivation of learning a few things until I can replace the time switch with a relay switch that is controlled by the Raspberry Pi using the data provided by the sensor.
I can check on a mobile device when I'm not at home or from the bedroom at night when it's freezing outside.
Just a very brief description, going into detail would be too complex. Just want to mention I got the parts now for soldering an analog circuit that gives an alarm with a piezo buzzer when the temp drops below 32 F or raises over a certain point using a thermistor.
Such a thermistor can be placed inside of the substrate of a myc culture to monitor temperature. Rising temp in contaminated tubs (bacteria) could be detected early. Many applications are possible with this.
Edited by Alpoehi, 10 December 2020 - 04:09 PM.