If you’d like the latest fixes or would like to contribute. Thanks Jonny Ervine!
I had some issues with Kingston SD Cards, but the SanDisk cards I’m using now have run for weeks without issues, so I’m changing the parts list to reflect that.
Also, after some 49 days, 16 hours, the display flatlines, as the reading routines start returning the same number over and over again. A reboot clears it, so just reboot once a month until I figure out what’s up.
Over the past summer, my vacation home had a small water leak for three months, and I realized that had I been measuring the humidity in the effected area, I’d have seen it go to 100% for a long time and I could have dispatched someone to fix the small problem before it became a big one. And since I’ve been playing with Raspberry Pi computers for a while now, and saw an inexpensive temperature/humidity sensor on AdaFruit, I had all the pieces I needed to implement an inexpensive network-connected monitor.
The Bill Of Materials (BOM):
Raspberry Pi Model B
Power Supply (I use PoE splitters, but any 5V 1A Micro-USB supply will work)
AM2302 (wired DHT22) temperature-humidity sensor: The AM2302 is a wired version of the DHT22, in a large plastic body. It is a basic, low-cost digital temperature and humidity sensor. It uses a capacitive humidity sensor and a thermistor to measure the surrounding air, and spits out a digital signal on the data pin (no analog input pins needed). Its fairly simple to use, but requires careful timing to grab data. The only real downside of this sensor is you can only get new data from it once every 2 seconds, so when using our library, sensor readings can be up to 2 seconds old. Read more.
Each Friday is PiDay here at Adafruit! Be sure to check out our posts, tutorials and new Raspberry Pi related products. Adafruit has the largest and best selection of Raspberry Pi accessories and all the code & tutorials to get you up and running in no time!
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.