Raspberry Pi has been very popular small computer board. It’s initial layout is quite flexible that allows it to use as standalone computer or embedded device with controllable I/Os. Probably standard Raspberry Pi is more oriented to be small single board computer, where you can connect peripherals like keyboard, mouse, display, Ethernet. The I/O part seemed to be left on a side. Eventually extension boards started to appear to fill the need of functionality like ADC, DAC, more digital I/Os. Eventually you end up stacking stuff on top like Arduino. But we like elegant things don’t we? So Raspberry Pi team has been working on different Raspberry Pi concept – Compute module. This is smaller module which have same BCM2835 processor, same RAM. Instead of SD flash there is a 4Gbyte flash memory. Practically this is it. Module is traced on DDR2 SODIMM sized PCB which actually fits this connector.
It has no external connectors like Ethernet, USB or audio but there are way more GPIOs. Module can be snapped in to any custom made I/O board that can have more controllable I/Os or interfaces like found on standard Raspberry Pi. So definitely module will have to go along with custom I/O board. It will give even more freedom to community. They’ve also taken care of example I/O board to get started.
chirag have built a wireless sensor prototype by using Beaglebone Black and MSP430. BeagleBone nad MSP430 sensor board is paired with Xbee RF modules. Sensor module is equipped with LM35 temperature sensor and LDR.
Module sends sensor data every second which is then reflected in webpage. Beagle bone runs LIGHTTPD webserver where page is hosted. Prototype proved to be working right, there are plans on second version of module with more sensors and probably fancier web interface.
Raspberry Pi and camera module alone is a great fun to play with. But when you start combining things, you start getting very interesting results. PiFace decided to experiment with bullet time effect by using 48 Raspberry Pi equipped with cameras and PiFace modules.
This effect got popular with famous Matrix effect where Neo avoids bullet by bending back. To get this effect working each camera has to be synchronized. This was done by connecting each board with network cable which yields to total ½ kilometer length. Comparing to professional setup this is relatively cheap solution to get things done. So it can be a great candidate for school class project or for low budget effect capture.
BeagleBone is accessed by using Websocket connection to small server. Then server interprets data and sends PWM to drive servo motor. If you would like to dig deeper there is a GitHub page where you can find latest source codes and library for driving PWM.