“The Raspberry Pi is set up as a LAMP server,” explains RasPiViv creator Nate Bensing. “I started playing around with the DHT22 temperature-humidity sensor – originally I just wanted to monitor that, the temperature and the humidity, but then I got into using relays to control the lighting and it just progressed further and further. I was just making this for myself and I posted on a forum. Then a lot of people seemed really interested, so I said I’d clean things up and throw together a guide.
“So the temperature and humidity sensors are read every 60 seconds and logged into a database. Using WiringPi and Adafruit’s DHT22 sensor (and the driver for it, which is brilliant and works really well), lighting is controlled by regular relays or relay modules, and the fan is just a basic transistor switch. The main idea behind the fan is that if the atmosphere is too saturated with water then the frogs can’t thermoregulate. So the database is read every five minutes, and when it reaches 95% humidity it then kicks on the fan to blow in some fresh air.
“There’s a whole web interface where you can check out the current readings. Check out the Demo section on my website and the first thing that pops up is my blue poison dart frog vivarium. It gives you the current temperature and humidity, and then also the readings for the last hour.”
Want to know more about Nate Bensing’s RasPiViv project? Check out the complete interview in issue 153 of LU&D!