Getting started on your first hardware project can be difficult. Luckily these days we have things like the Raspberry Pi. which put almost everything we need into a nice bundled package to get started on your first cool hardware project. Even better, the Raspberry Pi runs Rasbian, a variant of Debian, which makes it pretty familiar with those already comfortable with popular Linux distributions. The next step is to connect a sensor and it’s definitely easier than you think. But the question always remains, once I’m collecting my data, where will I store it and how do I easily setup some sort of notification service? In this post, I’ll tell you what you need to do to connect your first sensor, get RethinkDB going on your Raspberry Pi, and push that data to all your devices using PushBullet.
I wasn’t sure what I wanted to do for my first hardware project but having a Raspberry Pi gave me a great place to start. I knew though that if I kept worrying about voltages and GPIO pins I would never get started. So I took a leap and went to Adafruit.com and purchased my first temperature and humidity sensor. I choose the AM2302 because of the support I found on the Adafruit website and the special Python-wrapped C libraries which Adafruit had already written and put up on Github.
After my sensor arrived, I realized the three cables coming from the sensor couldn’t be directly connected to the Raspberry Pi as the GPIO pins are just that, pins. Where somewhere In my mind I had figured they were female connectors. Not wanting to dive into soldering and burn my fingers or play with molten metal, I decided that I would much rather ride my bike out to Fry’s and get some female-female jumper cables for a couple bucks.
Getting started working with the GPIO pins is also somewhat challenging. As I had already lost my Raspberry Pi instructions within the first 30 seconds of opening the box. Were there any instructions in there anyway? Luckily, the Internet is fully of documentation on the layout of the GPIO pins for each version of the Raspberry Pi. My Raspberry Pi 2 being somewhat different than the previous two. Make sure when wiring up your project that you follow a pinout guide such as this one. Plugging the wires in the wrong places can render your Raspberry Pi unusable, so check twice and plug once!
Featured Adafruit Product!
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!