Gert Board To Pair Up Your Raspberry Pi With The ATmega Microcontroller
You can now expand the General Purpose Input Output (GPIO) pins of your Raspberry Pi with a Gert Board. Gert Board is the brainchild of Gert Van Loo, one of the developers of the alpha version of the Raspberry Pi. With the addition of the 28-pin ATmega microcontroller, you have the entire Arduino Integrated Development Environment (IDE) at your disposal. Moreover, it is possible to add any of the following ATmega controller models to the Raspberry Pi – ATmega 48A/PA, ATmega 88A/PA, ATmega 168A/PA or the ATmega 328A/PA.
So, what does this mean for your Raspberry Pi? By adding the Gert Board, you get an 18V @ 2A port for your motor projects. You also get a 2-channel, 8-, 10- or 12-bit Digital to Analog converter along with a 2-channel 10-bit Analog to Digital converter. Additionally, you get 6-Open Collector drivers capable of 50V @ 0.5A, 12-Buffered I/O’s and three push buttons.
PiFace Digital Controller
If you intend to control external hardware via the Raspberry Pi’s GPIO header, the easiest way is to use the PiFace Digital developed by Andrew Robinson of the University of Manchester. The PiFace Digital has two onboard changeover relays, and this is the central feature of the add-on board. The changeover relays have open-and-close positions, which are accessible to the user. Each open-and-close position of the relay can handle 5V @ 10A maximum. You can program the board through Python, C or Scratch. Scratch has also developed an emulator, called the PiFace Emulator. This gives you a graphical control over the features of PiFace. Not only this, PiFace has additional onboard features such as eight digital inputs., eight open-collector outputs on connectors, eight LED indicator lights on the outputs and four tactile switches.
The Raspberry Pi has an onboard CSI port, which you can connect using a ribbon cable to the Camera Module. The Raspberry Pi camera module measures only 25mm x 20mm x 9mm. The tiny module has an Omnivision 5647 fixed-focus module that can handle 5MP still images, while weighing only 3 gm. You must use a 4GB or larger SD Card on your Raspberry Pi, as this is where the images from the camera are stored. The camera can handle resolutions of 1080p30 (1080 pixels at 30 frames per second), 720p60, and 480p60/90. The CSI bus on the Raspberry Pi is capable of handling high data rates streamed directly to the processor on board (BCM2835 ARM 11).
A Slice of Pi
This breakout board, called the Slice of Pi, is the least expensive of all the expansion boards for the Raspberry Pi. The board has a serial peripheral IO port expander, MCP23017, which adds 16-input/output channels to your Raspberry Pi. Apart from this unique feature, you can also use the board as a custom development area. One key feature of this Slice of Pi is the Xbee style connector mounts. Since this can support the XRF, Xbee and the RN-XV wireless modules, the functionality definitely expands the popularity of the board. Apart from this, you have easy access to the on-board GPIO, the 3V3, 5V; GND and the TX/RX solder points.