Operating system: Raspian Linux
Dimensions (XinoRF): 70.9 x 53.3mm
Weight (XinoRF): 25g
Dimensions (Slice of Radio): 30.3 x 34.3mm
Weight (Slice of Radio): 7g
Extras: 4GB SD card, USB cable, small breadboard, 5x red, yellow and green LEDs, 30x resistors, light sensor, thermistor, piezoelectric buzzer, 3x push-button switches, 25x jumper wires
While it’s easy to see the Arduino and the Raspberry Pi as competitors – they’re both low-cost electronic devices aimed at the hobbyist market, after all – in truth they’re extremely complementary: the Arduino excels at real-time control and sensing, while the Pi provides cheap network connectivity and powerful data processing capabilities.
That’s clearly been the thinking of Ciseco in designing the Raspberry Pi Wireless Inventors Kit, or RasWIK: a bundle of components and accessories, it’s designed to make working with the Arduino on the Raspberry Pi as simple as possible and showing users just what potential is opened up when the two are connected over a radio link.
Getting started couldn’t be easier: the kit includes a 4GB SD card with a customised version of the Raspbian operating system. Simply slide this into the Pi, pop the bundled Slice of Radio board onto the GPIO header and apply power.
The SD card includes an open source example utility for controlling the included Arduino clone, a radio-equipped microcontroller dubbed the XinoRF. Using this tool, a visual representation of the board appears on screen – and allows the user to turn outputs on and off, or read values from digital or analogue input pins.
With nothing connected to the Arduino, that would soon get pretty boring, but the kit also includes numerous components and instructions for various experiments and small projects. Using the bundled compact breadboard, it’s possible to get building simple circuits – remote buzzers, traffic lights, even a light and temperature sensor – in mere minutes.
The RasWIK has a serious trick up its sleeve once your device is built: an embedded radio on the XinoRF connects to the Slice of Radio with no effort, allowing you to place the XinoRF almost anywhere in the same building as the Raspberry Pi and still take control of it. The system uses the Lightweight Local Automation Protocol (LLAP), which allows for multiple devices on the same radio network – more XinoRFs, more Raspberry Pis, or some of the LLAP- compatible accessories also sold by Ciseco.
It’s here where the only real downside of the kit comes to light: although the RasWIK features optional radio-level encryption and the ability to run semi-private networks by altering the network identifier in the application source code, this is poorly documented at present and could confuse newcomers trying to run multiple independent networks side-by-side.
For the experimenter, though, it’s a minor point. While the kit runs LLAP out of the box, the radio can also be used as a point-to-point serial connection, and you can write your own protocol to run over the top if you desire robust security.
That minor issue aside, there’s little not to like about the RasWIK kit. The radios offer surprising range, and the Slice of Radio in particular is a very clever bit of design and sits happily on top of the Pi’s GPIO port without increasing its dimensions – meaning it can be used in conjunction with the vast majority of non-metal cases on the market.
The only real downside for those who enjoy experimenting with the Pi’s GPIO hardware is that the Slice of Radio does not include pass-through connections for the other pins on the header, despite only using power and the UART connection itself. Careful work with a soldering iron will allow you to fix that, but if you’re not happy with such modifications and have only one Pi, you’ll soon grow tired of removing the radio board in favour of other GPIO-connected devices you may have.
Although it would be easy to mark the RasWIK down for its poorly-documented security features, to do so misses the point: it’s an easy way to get started with wireless microcontroller development, and provides a great platform for adding sensors or actuators to a Raspberry Pi. If security is a worry, users can always roll their own protocol.