People who know Dawn Robotics well may be wondering about the grant we got from Jisc back at the start of August, which was intended to help us develop our robot kits further and to produce educational material for robotics. As we’re not going to be able to fulfill those commitments, this grant has been repaid in full. In fact, the need to do this was one of the reasons for making this decision now, rather than letting things drag out.

Now, whilst it’s a bit sad that Dawn Robotics is closing down, the good thing from a ‘cheap stuff’ point of view is the Closing Down Sale! So, please head along to our store to grab yourself a bargain. We don’t have many robot kits left, but we do have lots of Arduino Shields, Raspberry Pi Accessories and Adafruit items, all with up to 40% off.

For people who have already bought kits, or items from our store, please rest assured that I’ll continue to provide support for these items, and I’m holding back some stock in case I need to ship out spares or replacement parts. Also, the instructions to build our kits, along with the open source software required to do so, will remain freely available, and all the main parts we used are available from other UK retailers.

Finally, I’d like to say a big thank you to all the customers who have bought stuff from us over the years, and to all the people who have supported us and who have made this experience so much fun.

Happy robot building.

Regards

Alan

The post Closing Down Dawn Robotics appeared first on Dawn Robotics Blog.

Adafruit’s Servo Controller

At the moment these mainly consist of items to make your robot flashy, along with a great servo controller board, and a number of small items that we’ve found useful when building, and connecting sensors to our robots. However, we’ll hopefully be expanding the range of Adafruit items we stock in the future, so for now check out the Adafruit section on our website, and please let us know if there’s anything they make that you’d particularly like us to stock.

Seeedstudio 4A Motor Sield

Aside from that, we also have some new products from Seeedstudio. A nifty all in one accelerometer and compass board, and a 4A motor shield for the Arduino for those bigger robotics projects.

Finally, we are also now stocking a few extra Raspberry Pi accessories such as a case and a power supply.

The Official Raspberry Pi 2 Case

The post New Products – We now Stock Adafruit! appeared first on Dawn Robotics Blog.

Thank you so much to everyone that voted for us. What this means is that we now have the money to continue developing our robot kit, and producing educational materials to help teachers to teach robot programming in schools. Specifically, we’ll be developing some lesson plans for teaching robotics, and will hopefully be piloting these in a local school or college sometime before the end of the year.

The Jisc funding is delivered as part of a 6 month program, and so we hope to have the final version of the teaching materials ready around the end of January 2016. We’ll try to post a draft version sometime before that though for comments and feedback.

The post Update on Jisc Competition Entry appeared first on Dawn Robotics Blog.

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.

The post Why so Quiet, and Please Help us to Develop Pi Robot Educational Materials appeared first on Dawn Robotics Blog.

As part of our involvement with the Technology Incubator, we’re also fortunate enough to have been invited to take part in Pitch@Palace, a platform for young British startups organised by HRH The Duke of York on 5th November at St. James’s Palace.

We’ll be heading along with 2 other tech startups from the BRL incubator, Reach Robotics, and OmniDynamics. This is a great opportunity for us to explain our vision for robotics in education and research to a wider audience (see the slightly rushed video pitch below…).

As part of the Pitch@Palace event, there’s a Pitch@Palace people’s choice award which is given to the company that gets the most votes from the public. So if you could find time to support us and cast a vote for us then that would be very much appreciated.

The post Off to Pitch@Palace appeared first on Dawn Robotics Blog.

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.

The Dagu Arduino Mini Driver board used in the Raspberry Pi robot contains a L4941B 1A linear voltage regulator which can be used to run the robot from batteries. Linear voltage regulators are cheap, which helps keep the Mini Driver affordable, but they’re not very efficient, so a lot of battery power is wasted as heat. Also the Mini Driver, Raspberry Pi and a USB Wifi dongle use up quite a lot of the available 1A so there’s not much headroom for adding extra sensors to the robot.

By contrast, the UBEC we’re using is a switching voltage regulator which are a lot more efficient than linear regulators, wasting much less battery power. Also, the UBEC is able to provide up to 3A of current, so provided the batteries can keep up, this provides a lot more current to supply USB peripherals plugged into the Pi, and sensors plugged into the robot.

Wiring up the UBEC

Making use of the UBEC is very straightforward. If you’ve already wired up your robot to provide power to the Raspberry Pi from the Mini Driver, then first remove these wires. After that, connect the red input wire of the UBEC to the pin directly next to the on/off switch of the Mini Driver (this is connected to battery voltage), and then connect the black input wire of the UBEC to a GND pin on the Mini Driver. We’ve used the GND pin on the 3×2 programming header as this is unlikely to be used for anything else. Finally, plug the USB connector of the UBEC into the Pi and attach a set of 6xAA batteries to the +/- pins of the Mini Driver and you’re good to go.

Remove any power wires connecting the Mini Driver to the Pi.

Connect the UBEC to the Mini Driver and the Pi

Power the Robot using 6xAA batteries (preferably rechargeable)

Testing the Battery Life of the Robot

To help us test and compare different ways of powering our robot we’ve developed a little battery testing script using our py_websockets_bot control library (installation instructions here). This test script runs on a PC and connects to the robot over WiFi. It runs in a loop making the robot look in different directions, and then periodically making the robot spin either left or right. In this way we hope to simulate the conditions in which the robot might be used i.e. lots of stop/start motion. The Mini Driver has one of its ADC pins hard-wired to a voltage divider to measure its battery voltage, and so the test script periodically records this voltage. When the robot runs out of juice, it stops responding and the script can be ended, at this point the script saves the voltages out to a CSV file so we can plot how the voltage of the battery changes over time.

The graph below shows some of the tests we’ve run. All of the tests were run on our Raspberry Pi robot using a Model B, so we’d expect runtime improvements if using a Model B+, as this has lower power consumption. The voltage readings are quite noisy, but you still get the general discharge curve over time when running off batteries. The graph shows the advantage of using good rechargeable batteries (NiMH) instead of non-rechargeable (Alkaline) batteries. On rechargeable batteries (Duracell 2400mAh NiMH) the robot ran for approximately 3 hours, which was 3 times longer than when using Alkalines (Sainsbury’s Extra Long Life). The graph also shows the results of running the robot on the TeckNet iEP387 USB powerbank that we sell.

We’ll update this graph with more tests as we run them, i.e. we’re planning to run tests using the Model B+. Also, we’d be really interested to see the results of any battery tests that users run on their camera robots to see how they compare with our results.

Results of running battery_test.py using different power supplies for the robot.

The post Improving the Battery Life of Your Raspberry Pi Robot with a UBEC appeared first on Dawn Robotics Blog.

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.

The post Robotics and the Raspberry Pi Model B+ appeared first on Dawn Robotics Blog.

We recommend that the robot be powered with good quality, high capacity, rechargeable (NiMh or NiCd) batteries, such as Duracell 2400mAh NiMh . Non-rechargeable (Alkaline) batteries are not recommended as they will struggle to provide enough current to power both the Pi and the motors of the robot.

Good for robots

Bad for robots

Pretty (and also good for robots)

As an alternative to AA batteries, we’re now selling the  TeckNet iEP387 USB power bank which can be used to power the entire robot. The power bank is more expensive that the cost of 6 AA rechargeable batteries, but you get the advantage of increased runtime (approx 5 hours compared to 3hrs for the NiMh Duracells), and you don’t have to buy a battery charger.

In this blog post we show you how to use the power bank with the robot.

Connecting the Battery to the Robot

Please Note: If you are using a USB battery pack to power the Pi and mini driver, then you do not need to use the UBEC which we’ve started to supply with more recent versions of our Raspberry Pi robot.

Once you’ve built the robot following these instructions, Slide the iEP387 USB power bank into the chassis behind the wheels.

The iEP387 should come with 2 USB cables, a micro USB cable for powering the Pi, and a USB cable with 2.54mm connectors for connecting to the Mini Driver, and powering the motors. First plug the micro USB cable into the 5V 2.1A output of the iEP387 (the Pi needs this) and connect it to the power connector on the Pi (the extra cable can be wound around the Raspberry Pi mounting struts).

Secondly, use the USB power cable with red and black leads, and 2.54mm connectors to attach the 5V 1.0A output of the iEP387 to the battery pins of the Mini Driver (marked + and – next to the mini USB connector). The red wire should attach to the + pin and the black wire should attach to the – pin. Don’t worry if you get them the wrong way round though, as the Mini Driver has reverse bias protection.

Connecting the iEP387 USB Power Bank to the Robot

Make sure that you leave a bit of slack in the cables so that you are able to slide the iEP387 sideways slightly and press the on/off button.

Turning on the iEP387 Power Bank

Turning on the Robot

To turn on the robot, first switch on the power switch on the Mini Driver. This is important in order to provide power to the motors. Then slide the iEP387 sideways, and press the power button. This should turn on the robot.

Please Note: When using the new Model B+ Pi, it’s possible to knock the Micro SD so that it comes out slightly. In this situation the powerbank will turn off after a while as the Pi wont boot properly and so not enough current will be drawn to keep the powerbank on. If you’re seeing the powerbank turn off for no reason then please check that the MicroSD card is seated properly. This forum post gives more details.

Turning off the Robot

To turn off the robot you need to unplug the micro USB connector from the Pi, and turn off the power switch on the Mini Driver. This is not as neat as we’d like it, but there’s not really an easy way (without adding more hardware, and therefore more cost) to stop the Pi from drawing power from the power bank.

Unplug the micro USB cable to turn off the Pi

Pulling the power from the Pi shouldn’t damage anything as the robot’s software doesn’t write anything to the SD card. However, it’s always nice to let the Pi shutdown cleanly if possible, and so to do that you can use the shutdown button on the robot’s web interface.

 Updated: Extra Photos to Show Installation of Battery

I’ve had a couple of people say that their battery pack touches the wheels so have posted the following pictures to try to clarify things. The pictures are not great quality, but hopefully I’ll have time to update them in the new year.

There should be a small (approx 2mm) gap between the battery pack and the wheels

The battery pack should be held back by the plastic motor tabs.

As an alternative to inserting the battery pack in from the side, it’s also possible to remove the central support and slide the battery pack in from the front. This is a snug fit, but again there should be a few millimetres between the battery pack and the wheels. This gap can be increased by sliding the wheels slightly along the motor axles.

If the central support is removed, the battery pack can be slid in from the front.

There should be a few millimetres of clearance between the battery pack and the wheels.

The post New Product – A Power Bank for your Raspberry Pi Robot appeared first on Dawn Robotics Blog.

• much faster camera streaming. Initially the camera was streaming images at about 4-5 frames per second using raspistill and mjpg-streamer, but we’ve now written our own camera streamer, and got it streaming at 15fps which is much smoother, and makes driving the robot around a lot easier.
• support for more WiFi dongles when working as an access point. Our previous software release mainly worked with WiFi dongles that used the same chipset as the Edimax EW-7811Un (the hostapd rtl871xdrv driver). It was possible to get it to work with other WiFi dongles that used the hostapd nl80211 driver, but it required a fairly technical user. Now our software should work with a much wider range of WiFi dongles with no change required.
• we’ve added a shutdown button. Previously the robot was turned off by just cutting off the power. This was very unlikely to corrupt the SD card as nothing was written to it, but a lot of users felt uncomfortable with not doing a proper shutdown. Now a shutdown button in the web interface provides peace of mind.
• more configuration options. The configuration webpage of the robot has been expanded to offer more options to control the movement of the robot.

As before, there are multiple options for getting hold of this software. If you already have an SD card then you can download an SD card image with all of the software installed here (go for the most recent version). Update: If you use our SD card image, please remember to expand it after installation by running

sudo raspi-config

and choose the ‘Expand Filesystem’ option.

Alternatively, we sell SD cards with the image preloaded in our store. Finally, for those who want to set up the software from scratch, or who want to modify it for their own robotic projects, we give full details for building the SD card, and installing all the software, here.

We believe that the Raspberry Pi is a great platform for robotics, and have got a number of tutorials for our Raspberry Pi Camera bot lined up for the coming months. If there’s anything in particular you’d like to see, please let us know.

The post New Software For Our Raspberry Pi Camera Robot appeared first on Dawn Robotics Blog.

We’re glad to see that robotics is rising in popularity as something to do with your Pi. We ran a store at the Jam, and other robotics vendors there included The Little British Robot Company and PiBorg (with their very cool DoodleBorg tank). Ben from Phenoptix was also there with a neat little laser cut robot arm. We saw some cool Raspberry Pi robot projects from Leo White, and had a nice chat with Ian Renton, the guy behind the Raspberry Pi tank.

In the afternoon we gave a talk on combining the power of Arduino with the Pi to build Raspberry Pi robots as we have with our Camera Bot. For anybody interested the slides can be found here.

Pi Jams are a great way to meet interesting people, and get ideas for your next Pi project, if you haven’t been to one yet then we recommend that you keep an eye out for one in your area and head along.

The post Attending the Linux User Pi Jam appeared first on Dawn Robotics Blog.