April 2009
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Welcome
Hi, my name is Len Holgate and this is a blog about my new project to design and build a hexapod robot; a mechanical vehicle that walks on six legs… By day I design and build high performance TCP and UDP servers for the Windows … -
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A-pod, an ant inspired hexapod
This is the kind of thing that I mean when I say ‘hexapod robot’. I particularly like the head and mandibles. More details can be found here: http://forums.trossenrobotics.com/showthread.php?t=2762 and here: … -
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Micromagic systems
Micromagic systems do robotics and animatronics for the film and tv industry and have quite a nice selection of hexapod robots. It’s especially interesting to see the evolution of their robots here. Their latest stuff is very … -
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Servos with status feedback
I saw these Dynamixel DX servos mentioned on Trossen Robotics this morning, see here. They’re interesting because they have a richer interface than the normal hobby servos that I’ve been looking at and they provide a multidrop … -
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Useful links and suppliers
So far most of my more interesting components have been purchased from Cool Components mainly because they’re UK based and they stocked stuff I was interested in. I found them via SparkFun which is a treasure trove of fun; … -
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Pulse width modulation for servo position control
First some basics: servo motors are what I’ll be using to provide movement for the robot. Each leg will consist of at least three servo motors (1 at the knee and two at the hip). As you’ll see from the wikipedia link above, … -
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The servos are twitching
My package from Cool Components arrived this morning. My choice of prototyping equipment was quickly validated when I plugged together the Arduino and the Pololu servo controller board, plugged in the servos and servo power supply, … -
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Prototype leg v0.1
I spent a little time at the weekend putting together my three servos into a prototype leg. The idea is that this very quick and very dirty little experiment should give me some more avenues to explore; and something to show people. I had … -
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Thoughts on the proto leg
The prototype leg has some fairly major failings from a mechanical point of view. The only part that may eventually find its way into a weight bearing leg is the lower leg where the cut out around the knee servo provides ample support for … -
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First steps in embedded programming; first build the hardware...
This week I managed to scrape together some time to play with some of the non prototype bits and pieces that I purchased for this project. First off was breadboarding a MAX232 chip so that I could talk via my PCs serial port to my … -
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More thoughts on the proto leg
I adjusted my quick and dirty servo controller program to calculate the number of moves required for the servo that needed to move furthest and then spread the movement of the other servos across the same number of moves. So, given that the … -
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Once more with feeling
Having decided that the graduated servo positioning method was the way to go to allow for leg sensors to work correctly I started thinking about leg sensors. Here’s a new lower leg with three switches, one on the foot, one to the … -
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Books for programming an AVR micro
So far I’ve bought three AVR programming books. AVR: An Introductory Course, Programming and Customizing the AVR Microcontroller and Atmel AVR Microcontroller Primer: Programming and Interfacing (Synthesis Lectures on Digital Circuits … -
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The servo controller problems weren't power supply noise...
I’ve been testing the new leg with one power supply for the servos and one for the electronics and all is working well. I expect that all would be working well if I were using a single power supply for both, as long as I was using the … -
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Arduino multiple serial disappointment
Tonight I took a look at the ‘software serial’ support in the Arduino. I can’t say I’m that impressed… The Arduino has a built in hardware UART (a hardware serial port) which works as expected. It allows you …
