(If you’ve no time to read then could you please just spend a moment and vote? Thank you!)

Readers who check back on this blog from time to time may have noticed that since the end of November 2014, we’ve been very quiet, and nothing much has been written on this blog (apart from responses to comments). The reason for this is that I (Alan Broun) have been focusing pretty much full time on trying to finish off my PhD at the Bristol Robotics Laboratory and this hasn’t left much time to spend on Dawn Robotics (which is based in the BRL Technology Incubator). My colleague Martin, has been doing a wonderful job, packing orders, building kits and keeping Dawn Robotics going over the last 5 months, but I do most of the development work, so things have been in stasis for a bit.

Now though, I’m almost (almost… so close…) at the point where I can hand in, and although I do need to go off and do some contract programming work for a couple of months to rebuild my finances (Dawn Robotics doesn’t quite pay the bills yet) I am hopeful that Dawn Robotics will soon be back to producing new stuff.

This brings me to the point of this blog post. Dawn Robotics has entered into a competition run by an organization called Jisc which is offering up to £20,000 to help startup companies to develop and pilot products for use within schools and universities. But in order to be considered for a prize we need votes from members of the public i.e. you!

The product that we’ve put forward for consideration is our Raspberry Pi Camera Robot. This was originally released last year, targeted at hobbyists, but since then, a number of tech savvy teachers have bought the kit, and started to use it in schools. This makes sense in a lot of ways, as computing and programming are being seen as increasingly important in UK schools, and we feel that robotics is an absolutely fantastic way to engage kids and get them excited about programming. The trouble is, that it’s not as easy to use the robot in schools as it could be. The documentation for the robot is a bit lacking, being spread out over a number of blog posts, and we don’t have any dedicated teaching materials, such as lesson plans to use with the robot.

If we were lucky enough to win funding in the competition, then we’d use the money to change that. We’d use the money to improve the documentation for the robot and to create a range of lesson plans to make it easy for teachers to use the Pi robot in schools. We’d also use some of the money to refine the kit and its software to make it easier to use in schools (currently, connecting multiple robots to a school’s network is tricky). Also, the kit would be piloted in a number of schools to see if there were any other ways that we could improve the kit further. You don’t have to worry that this is all for for the benefit of Dawn Robotics either. The documentation and lesson plans will be released under a Creative Commons Share Alike license, and all of our software for the Pi Robot is open source under the BSD license. So hopefully, enthusiastic teachers will be able to get value out of the lesson plans and software, even if they don’t have one of our robot kits.

Anyway, hopefully you’re convinced. Please check out our pitch video below, and vote for us here. Also, if you could pass the link on and encourage other people to vote, then that would be most awesome.

A UBEC provides a nice efficient way to power your Pi from batteries

We recently started selling a USB powerbank which can be used to power the Raspberry Pi robot kit that we sell. Using the powerbank provides great battery life, but we’re still interested in making the robot run well from AA batteries, as this may be the cheaper option if you already have rechargeable batteries and a charger lying around.

Testing battery life

Therefore, we’re modifying the kit a bit to include a UBEC (Universal Battery Elimination Circuit). This is an efficient switching voltage regulator which takes the load off the linear voltage regulator of the Mini Driver and improves the running time of a robot being powered by AA batteries a lot. This post gives some details about why we’re making this change and also describes a battery testing script that we’ve written to determine what kind of run times can be expected for different methods of powering the Raspberry Pi robot.

Continue reading →

The new Model B+

So, the big news this week (if you’re a Raspberry Pi fan) is that the Raspberry Pi foundation announced the release of an upgraded version of the Model B Pi, the Model B+. The Raspberry Pi Model B+ is a really nice incremental update of the Model B, and it’s especially good for people wanting to use the Pi in robotic projects. This is because, alongside extra USB ports, it now uses switching voltage regulators which means that it consumes less power (between 0.5W to 1W less) and therefore it will last longer on batteries.

As soon as we got a Model B+ this week, we put it onto one of our Raspberry Pi Camera Robots, and it works great. The Model B+ has a different layout and mounting holes than the Model B so we’ve updated the assembly instructions for the robot to show how the Model B+ should be mounted.

We’ve also released a new version of the software for the robot, as the Model B+ needs different drivers for its USB and network ports. This new software has a few bugfixes, and also allows the robot to be driven at slower speeds than before. This new feature may not sound like much, but with the old software, the motors often couldn’t be made to go slower than about 33% speed before they stalled due to friction in the gearboxes. Now by driving the motors in a different way, we get the motors to turn with more torque at lower speeds to overcome this friction. This means that it’s easier to drive the robot whilst looking through the camera, and makes making precise turns easier.

The new SD card image can be downloaded here. Other options for getting the software are discussed here.