PI A+, B+, 2, 3
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This project combines a whole heap of modules to enable a Raspberry Pi to power a large 1.2 inch 4 digit 7 segment display. A small switch switches the display between showing the temperature and the current time. The project uses a real-time clock (RTC) to ensure that the Pi always has the correct time, even if it is not connected to the Internet.
This new Adafruit Pi Plate makes it easy to use an RGB 16x2 Character LCD. We really like the RGB Character LCDs we stock in the shop. Unfortunately, these LCDs do require quite a few digital pins, 6 to control the LCD and then another 3 to control the RGB backlight for a total of 9 pins. With this in mind, we wanted to make it easier for people to get these LCD into their projects so we devised a Pi plate that lets you control a 16x2 Character LCD, up to 3 backlight pins AND 5 keypad pins using only the two I2C pins on the R-Pi!
To keep costs low, the Raspberry Pi does not include a Real Time Clock module. Instead, users are expected to have it always connected to WiFi or Ethernet and keep time by checking the network. Since we want to include an external module, we'll have to wire one up. We'll go with the easy-to-use and low-cost DS1307.
In this tutorial we'll be showing how to utilize a DHT sensor Python library based on C for high-speed GPIO polling to handle bit-banged sensor output. Many low cost sensors have unusual output formats, and in this case, a "Manchester-esque" output that is not SPI, I2C or 1-Wire compatible must be polled continuously by the Pi to decode. Luckily, the C GPIO libraries are fast enough to decode the output.
Now that you've finally got your hands on a Raspberry Pi® , you're probably itching to make some fun embedded computer projects with it. What you need is an add on prototyping Pi Plate from Adafruit, which can snap onto the Pi PCB (and is removable later if you wish) and gives you all sorts of prototyping goodness to make building on top of the Pi super easy.
Raspberry Pi’s popularity makes things so easy that it is almost scary. I set forth on a simple starter project of having the Pi show me when new GMail messages arrive. After some searching it seems that lots of people are already talking about how to do this and there are some great examples. Michael over at MitchTech had the most ready to go code which I pilfered from. Adafruit's Cobbler Breakout Kit makes the bread board experience even easier with the clearly labeled pins for each of raspi’s GPIOs.