Thursday grab bag


Example GUI

Want to control the temperature of your barbecue, smoker, firepit or clambake over a web interface? Here’s the Raspberry Pi-powered HeaterMeter. Bryan Mayland says:

HeaterMeter for RaspberryPi joins an Arduino / AVR ATmega328 microcontroller with OpenWrt running on a RaspberryPi $35 wonder-computer for the purpose of providing oven-like control of a charcoal BBQ grill via web interface. The microcontroller controls a fan which limits airflow to the pit, displays the current status on a character LCD, and passes the data on to the RaspberyPi which streams real-time updates to connected web browsers. The website also works on mobile browsers running Android or iOS, allowing users to unchain themselves from their grills and partake in many life-enriching activities such as

  • Going to the grocery store to buy more beer
  • Going to a bar to drink more beer
  • Not get off the couch, where your beer is
  • Possibly other non-beer related hobbies


Dean Ellis has got Monogame running on his Pi. There are details of exactly what hacks he’s used to get it running so well on the YouTube page that this video comes from.

Monogame is an open source implementation of the Microsoft XNA 4 Framework – and it gives us all kinds of ideas about game development on the Pi. You can read some more about Dean and his Pi here.

Make Yourself at Home

We’ve been seeing a lot of visual artists using the Raspberry Pi in their installations. Whether you’re driving video or if you want to drive something with wheels, the Pi offers artists a much cheaper way of getting to their goals than the old “borrow someone’s old laptop” model. We’ve seen Pis being used in the Tate Gallery’s new Tanks in London; we’ve seen them being used in installations at Milton Keynes shopping centre. Most recently, I’ve heard from Martin Beha, who was working on the electronics side of an installation by Austrian artist Robert F Hammerstiel in Hannover. He used Raspberry Pis to  make three lawnmower robots talk to each other. (You can see them from about two minutes into this video.) The result is curiously charming.

Make Yourself at Home

Click for more on the installation

Martin says:

The communication is established through Wireless LAN. One of the Robots is configured as a server and delivers a (completely wrong but usable) time via NTP for synchronisation. It also calculates the start time for the audio files and delivers it to the other robots via SSH and “at”. The audio is taken directly from the analog output and is amplified by an 18W amplifier module. The sound quality is quite satisfactory for speech.

The devices are powered by a second battery because the manufacturer of the lawn mower robot has built in a function that monitors if additional current is taken from the main battery and stops the robot. The 5V is generated by DC/DC-Converters for car use. Other included circuits are for example a differential amplifier against an audio ground loop and a deep discharge protector.

I chose the Raspberry Pi for reasons of flexibility, size and because there was a very limited budget. The original plan was to communicate via Bluetooth Class 1 dongles and rfcomm to get a virtual serial connection. Because of several bugs in Bluetooth I could not connect the devices and decided to choose Wi-Fi as an alternative. Depending on different (resistor) jumper settings on the GPIO-Port, the RPIs recognize their conversation role after startup and play the right file. The jumper also defines the role as server or client. So I was able to use the same SD-Card image for all robots.

The actual audio files are mp3s of a dialogue about the sense of a robot’s life, spoken by three TV announcers of Austrian national television (Austrians will surely recognize their voices).

 STEM – training the teachers

There was a big Raspberry Pi event in Manchester last week, where a large group (including our very own Pete Lomas, accurately described by as “charismatic“) came together for a CPD/networking event for teachers at the Museum of Science and Industry.

Pete Lomas

Krisma? Bags of it.

We’re not alone in recognising that there’s a lot to be done before a new Computing syllabus arrives at schools next year in helping teachers out of the old ICT mindset and showing them how easy starting with the Pi can be. We’re really pleased to see how seriously teachers are taking the Raspberry Pi, and, as always, incredibly grateful to STEMNET for their tireless volunteering. This was the first of a series of events, where teachers were learning how to use the Pi with Manchester University’s Pi Face, getting to grips with Scratch and Python, and working on cross-curricular activities with the Raspberry Pi. A number of STEM ambassadors from industry also attended, doing that support and mentorship thing that STEMNET does so well. (I don’t think I’ve been to a single Raspberry Pi event that hasn’t been attended by at least one STEM ambassador.) We’d like to thank every one of them, and all of the teachers who are working so hard on getting to grips with a new piece of kit – we’re very grateful.

Jude’s cardboard case

Pete Wood from DesignSpark put me onto this most excellent little series of tutorial videos from Jude Pullen. Jude is a fan of cardboard. Having watched this, so am I!