If anyone is interested in purchasing a 914 PC Bot, there's one currently on eBay with quite a low starting price and no reserve.

Bidding has already taken off even though the auction still has over five days left to run. You never know - you might get a bargain!. Check out the auction here.

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C6Jones720 has written a short report on his work to easily achieve stereo vision for the 914.

Typically stereo vision is quite tricky because two web cams have to be used together at the same time. Chris has utilized a CCTV 'quad processor' to combine up to four video feeds - one into each quarter/corner of the video stream, so that the resulting video image can be processed in one go and all the cameras are frame-locked together.

Chris has also started to dabble with Microsoft Robotics Studio 1.5 which includes some sample vision applications for face and hand gesture detection that work with normal web cams. It's worth downloading Microsoft Robotics Studio and running these demos - I found they worked straight away with my web cam after installing and typing the command lines Chris has detailed into the Microsoft Robotics Studio command shell.

You can download Chris's report here: 914RobotHeadPart1.pdf (295Kb)

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White Box Robotics are currently redeveloping their Microsoft Robotics Studio services for the 914 PC Bot. You may remember that there was a Beta release of the 914 MS Robotics Studio services which is still available on request to those interested. However, the final release will be quite a rework from this, which allows at this stage, for input from the community for feature and functionality suggestions.

Microsoft Robotics Studio version 1.5 has also been released since the Beta 914 MSRS services were written, which has come along with a lot of updated documentation and tutorials. You may or not know that MS Robotics Studio applications can be written in Visual Studio .NET using MS Robotics Studio as an add-in component to the project, this allows you to build on top of the MS Robotics Studio framework and existing hardware support it provides. Those of you who have used the White Box Robotics 914 .NET components may not find MS Robotics Studio too much of a step in a different direction, as well as finding that lots of other off the shelf hardware is already supported.

If you have any feature or functionality requests that you would like to see in the final V1.0 release of the 914 MS Robotics Studio services, or any other input that will be useful to the White Box Robotics MS Robotics Studio development team, then please post in the thread below.

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You will probably remember C6Jones720's series of articles on power and charging for the 914. If you missed them then check out The Biggest Beam Robot, In-flight Refuelling, and the Supercharger Powerpack.

Chris has now taken this theme further to produce an autonomous charging solution using IR beacons and Odometry. You can read the article in PDF format here: 914ChargerLocationByBeaconingAndOdometry.pdf (107Kb).

Chris has also produced a film of this is action and put it on YouTube which can be found below:

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This week Odometry Man has a relaxing time, but not for long - because there's always an odometry emergency somewhere in the world!!

This is the first episode of a multi part storyline. Please click on the preview to the left to view this week's episode of Odometry Man in full. (320Kb).

Comic episodes will still be published each week on Mondays and remain archived in the 914 Comic Series section.


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White Box Robotics have updated their corporate website with some new info on the 9 series PC Bot.

There are two new downloadable PDF brochures about using the PC Bot with the WBR 914 .NET controls and also Player/Stage/Gazebo, which you can find on the product overview page. These are definitely worth a read if you've not looked at using either Linux and Player or .NET on your Bot yet, or you are thinking about purchasing a 914.

The specification page has also been updated with the addition of a new off-the-shelf variation of the 914 called the 'Extreme Edition'. The new model features a 2Ghz Core 2 Duo by default, but a lower spec Bot is still available as well as any other custom variation you would like as always.

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You'll notice that the lifting motion is quite slow - if you look closely you can still see the motor shaft coupling rotating right up until the blue under-head lights start flashing. The lifting speed could be improved with a geared DC motor and some end switches, but the main limiting factor here was stepper motor torque vs step speed.

All in all it serves the purpose for housing extra sensors such as sonar and my IP web cam - the head wouldn't have to lift very far in order for those to look out. The total lifting height is around 5"/12cm.

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This is the last part of the 914 rotating and lifting head mod. You can check out part one and part two if you missed them. All the photos can be found in the image gallery.

This week I have been mostly working on the rotating mechanism which I've rebuilt twice. The main issue is that there is quite a lot of weight to move around due to the lifting mechanism and it's stepper motor. The original plan was to use a direct drive method from the stepper motor which was mounted under the top plate of the chassis in the top drive bay. This worked ok, but even using half-stepping the movement was still quite jerky.

I decided that I needed some gearing to make the movement a little smoother. Firstly I built a gear box using some plastic gears and mounted that in the chassis. This worked ok, but the resulting motion appeared to be a little like some sort of Victorian era steam powered invention. I think this is because quite a lot of momentum builds up in the head as it turns, and because there are gaps between the gears this causes a sort of 'buffeting' as the head gear bounces off the motor gear. Of course this is magnified to the outer radius of the head so it is quite noticeable.

As the 914 itself uses stepper motors to drive it's wheels, I took a hint from the way the drive train has been designed and next I used a toothed timing pulley and belt combination. This came out a little larger as the two pulleys are further apart than the gears were, which unfortunately means that the assembly occupies most of the top two drive bays at the rear of the Bot. I relocated my Buffalo Airstation wireless bridge to a slot behind my Alphacool LCD display at the front of the Bot, which is largely wasted space, to make space for the larger size of the gearbox. The results from this drive train is much better - it feels much more solid and there is much less slack when the head is stationary.

I've also sorted out the stepper motor drivers which are each made from Picaxe-18 high power project boards programmed to pulse the right stepper motor phases and the correct time. I've also added a piggy-back board to one of the project boards to take a spare output from the Picaxe to turn on some blue LEDs mounted up in the head shell. Both drivers share an RS232 bus and are currently connected to the mini-itx board's serial port. I can therefore command the rotating motion for speed, direction and distance, as well as turn on and off stepper motor holding power. The lifting stepper motor driver takes commands for 'up' and 'down' and deals with the blue LEDs which can be turned on and off at will.

Watch this space in the next two days for a video of the mod in action!

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