Show and Tells – April 2013

IMG_9144A bumper session of projects were seen this night starting with a real live Pi Camera from Pete W. The camera is smaller than a £2 coin and gives 1080p 30fps video (no IMG_2018sound). It has 4 mounting holes and a 10cm connecting cable (max). These should be available post 14th May.


Pete M. then followed explaining how the Health and Safety messages were projecting on the screen in the room. All powered by a Raspberry Pi! Pete used an auto login LibreOffice slideshow to show slides saved in open document format from the authors with PowerPoint. These are now scattered around RS and he’s put details of the configuration on github (link to be provided).IMG_9145

Alex E. had another Wii controller project on the go with a remote control car complete with brake and headlights and indicators and driven by an aircraft propeller and with an ‘on-board’ Pi as the controller. He’s yet to build it all inside the car (he may need a bigger car!) but the concept using the Wiimote and Nunchuck as the controller linked via bluetooth (Tesco teknika branded) and using model aircraft batteries. Motor control is via a Gazunti CPLD and a PWM (Pulse Width Modulation) controller. Details are on his blog at

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Next up was our ‘biggest’ demo yet – a full video wall powered by Pi’s. This has been featured on the foundation site a few weeks ago and Alex and Colin from the Culham Centre for Fusion Energy (CCFE) had built the system in C to run on the Pi’s. They showed a 4 screen setup but have run a 9+4 setup and the software is scalable to any size or shape. They expect to licence the software/design at some point. More details are available here: IMG_9164 IMG_9159

Dave R showed his Pi with a webcam motion detection system and linked to a DSLR camera such that a digital image is captured, say when a bird lands on a birdtable. The system works but only for the first shot so some debugging to be done. That said he’s wired into the DLSR via relays, Piface board and GPIO on the Pi.IMG_9170

Paul de F had connected a simple touch screen to the Pi to allow control and display. The screens are semi-intelligent storing screen images and having a sound output available. The screen images are loaded via a Windows app and USB connection. The Pi can then control the display of those images.IMG_9171

His second demonstration was with a programmable LED strip and infrared receiver which allows a python script to read the codes from a Sky remote control and flash the LEDs in various patterns and colours. The LEDs are driven by SPI and can be daisychained up to 1024 LEDs.IMG_2029 IMG_2023

Next up Paul M and Annierei L showed us their ChiPhone box. This is a pi in a child friendly box with buttons and microphone that allows voice messages to be sent/received. With simple record and ‘To/play’ buttons it makes for an easy messaging system connected to WiFi. See for the online product and Paul is after some help with Python scripts so email him at paul@planet.comIMG_9176 IMG_2035



John L then finished our live demos with a view of his RSS feed collector (which is powered by an always on Pi) and his analysis tool. Unfortunately the data volume filled his 8gb card on the pi so he had to resort to a laptop for the demo. The Pi collects data from various RSS feeds every 30 minutes and stores the results in a MySQL database. Instead of a 50W laptop it now takes 2W and can be left on all the time. With some PHP and judicious use of JSON files to index the data he was able to show the trends in keywords over time thus showing either peaks of activity or trends of ‘chatter’ about topics.IMG_9178

Alex G was unable to appear but sent his contribution via YouTube He’s fitted out his family car with a ‘Toddler Entertainment System’ which is a screen, Pi and RaspBMC installation in the vehicle. This allows favourite childrens videos to entertain any youngster in the back seat. Powered via car mobile phone chargers and adaptors the Pi and screen can be entertaining the toddler in minutes. One of the more interesting components was the headrest support which he had made with 3D printed components to hold the screen safe.