The later LEGO trains and Technic examples are controlled via the "Power Functions" system, which is in effect a simple infra-red remote control for the user and an IR receiver connected to the motor unit in the train or model. Thanks to the relatively simple nature of the IR signal used and the open-nature of LEGO's documentation - it's easy to reverse-engineer it and create your own controllers.
Alan Nishioka has done just that, by deconstructng a PF remote control, and analysing the signal using a digital storage oscilloscope. With this data he's created a Raspberry Pi-controlled IR transmitter that can be the basis for all manner of Pi-controlled LEGO trains or Technic models. Furthermore with the addition of a Bluetooth LE module, the battery charge can be monitored and reported back to the system when low.
This is a great example of how consumer toys can be modified for even great control, so visit Alan's interesting website to get started. And for more, we're on facebook, Google+, and twitter - so follow us for news and product updates as well.
If you're looking for a neat way to add external circuitry to your new Raspberry Pi model A+, B+ or 2 model B then check out our new PiBreak Plus Raspberry PiPrototyping Board:
This is a great way to add your own electronic components, circuitry, sensors or other devices to your Raspberry Pi model A+, B+ or 2 Model B - any of the current Raspberry Pis with a 40 pin GPIO header. The PiBreak Plus also includes a GPIO female header to solder yourself, and a pair of nuts, bolts, washers and spacers to ensure a a great fit.
And in the Freetronics fashion we've used a quality gold-plated (ENIG) PCB for durability, brought out all the power rails along with the GPIO next to the prototyping area to make adding circuits a breeze. Furthermore the pinouts are labelled on both the top and bottom of the PCB to save time referencing the right GPIO pins. For more information and to order - visit the PiBreak plus page now!