PiPurr Server

All the best hacks and open-source projects come about by scratching personal itches. In fact when asked by friends and acquaintances “How do I start with coding – what should I write?“, that is my usual answer – “Find something you don’t like or would like to improve and do that“.

This brings us to the idea of PiPurr, what I like to call the Remote Cat Interaction Server.

Whenever we go on holiday, we never really get to relax, because Hannah is always asking me things like “Do you think the cats are OK?“, “What do you think the cats are up to?” etc. PiPurr is the solution to this problem.

The goal is not just to be able to keep an eye on what the cats are doing when away from home, but also to interact and play with them remotely too.

PiPurr is a simple client-server solution. The server runs on a Raspberry Pi, for low power consumption and provides the functionality – capturing images, dispensing treats, making sounds play from the speakers etc, and clients connect to this over HTTP and request those actions.

PiPurr for Android

The server is implemented as a small Python web server, using HTTPServer that, instead of serving static files from a directory, exposes a small number of URIs that correspond to those actions. This means that all that is required to access it is a browser. A summary of the actions are:

• /cats.jpeg – Capture and return a photo from the webcam. Uses OpenCV.
• /sound – Play the sound out the speakers to entice the cats over.
• /treat – Dispense a cat treat – Currently in development, and will use a PicoBorg stepper motor to drive a treat dispenser. Keep a look out for another blog post about this in the future.

The decision to use the (rather large and fiddly to get working on Raspberry Pi) OpenCV for image capture is down to the fact that in the future I am going to write a cat detector, and possibly other vision-based functionality.

A neat addition to the server is the LedBorg, which is an RGB LED add-on, set to flash different colours depending on what happens when requests come in. Red for 403s, 500s etc., green for 200 on the image URI and blue for 200 on the sound URI.

Sharing

For ease of use, I also developed an Android client that allows easy access to PiPurr whilst out and about. The app also allows for sharing of the captured images over email, Facebook etc.

I will be adding more functionality to the solution as time goes on. Some of the things I have planned are:

• / – Implement a web UI to control it easier with a web browser.
• /laser – Move a laser pointer or similar cat to about with motor control.
• /video – Stream live video.

I plan to talk about this project at BarCamp Canterbury on the 27th April 2013 if you would like to find out more, or have any cool ideas.

And because I am a slacker, I forgot to thank matth for the chip holders and Mex for being a Boris. Cheers!

OggCamp is a Barcamp-like event that focuses on free and open culture that has just hosted its fourth annual event in Liverpool.

Some of us from CantHack had attended last year’s event in Farhham, where we delivered talks on reverse engineering and HGD, and this year two of us (Tris and Han) travelled the long journey to Liverpool to once again spend two days meeting, socialising with and learning from a wide cross-section of the geek community.

RFID Rhythm Generator

Han was on the crew for this year’s event, which meant early starts and lots of helping out, although that did mean that I got chance to wander around finding talks to go to.

There were so many interesting talks on the schedules that it was impossible to see all the talks that I wanted to.

I did get to watch about many different subjects including QR Codes, OggBox (an open hardware Ogg player) to Nanode (an Arduino clone with built in networking and RF communications, more on that in a bit).

I also really enjoyed some of the more light-hearted talks such as Alex Martindale‘s look at error messages over the years (inlcuding a huge screen showing the Sinclair Spectrum start screen – which brought back many happy memories!), and an interview with Stephen Fry which, although pre-recorded, was very engaging and more interesting than I would have initially thought it would be.

This year’s OggCamp was also the first to feature an Open Hardware Jam, where we witnessed many awesome hardware hacks like an RFID rhythm generator, DIY retro computers, 3D printing and textile hacking.

I also bought myself the awesome Nanode RF, which as mentioned before, is an embedded development platform similar to an Arduino but with integrated Ethernet and an RF transceiver for wireless connectivity to sensor nodes.

Nanode

It is sold in kit form so I have all the fun ahead of soldering the components together to make the board. When finished, I plan to hack together some home automation/monitoring with this and a Raspberry Pi. Of course those hacks will also appear here in the near future.

I also took a few photos of the event, which are located on my Flickr page. It’s also worth searching Flickr for ‘oggcamp’ and ‘oggcamp12′ to find more.

Thanks so much to the organisers from Linux Outlaws and Ubuntu UK Podcast, and to Les Pounder for organising the crew! See you all again next year! CantHack will be back!

Digibury

Thanks to everybody who came to Digibury this week, we had a great time and we hope the people who came enjoyed the session. The slides are available below, as well as the light painting pictures you made! I am probably going to reuse the session for TinkerSoc at some point so please leave any feedback you have in the comments with any way I can improve the talk.