Call for picaxe robot pages

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chipwich

Member
I've scoured the web for all sorts of small DIY robots: sumo bot, microbot, symet, pummer, photovore, and the like. Amazingly, I see a very small number of robots using the picaxe, even though I can't imagine a more capable microcontroller with a straightforward development environment in such a low price range.

Most of the BEAM robots use simple discrete logic, even when a 08M would add HUGE flexibility to their capabilities without much cost.

For my project, I didn't want to spend too much time on the chassis and looked around for a suitable platform. Unfortunately, most chassis kits (e.g. base plate, gears, motors, and wheels) cost at least 50% of a Boe-Bot! And for that price, nothing compares with the fine engineering in Roomba's new iCreate product for hobbyists.

Has anyone here built a simple robot using a picaxe? What are the best platforms for such a project? What about links to microbots or picaxe bots?

My early attempt at a robot/toy is at <A href='http://medcosm.com/picaxe_robotoy_two.htm' Target=_Blank>External Web Link</a> if it helps stimulate some thought. Overall, I'm pretty happy with the low-cost, high flexibility, rapid construction, and ongoing entertainment value of the project, but I'd like to see what others have done in this area.

 
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moxhamj

New Member
That looks quick and easy. Stan will be very pleased to see the breadboard. I like using R/C cars for the hardware - you get so much for such a small price. Move up from the very bottom end of the market and the steering will be proportional and driven by a servo, which the picaxe can drive directly. And there is always a point somewhere on the board where you can cut a track and drive the motors directly.
What you have working is a great starting place to add other things like infra red/ultrasonic range finding, bump sensors and the like.
 
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tarzan

Senior Member
Two Wheeler Robot <A href='http://homepages.paradise.net.nz/danchez/picaxe/Two Wheeler.htm' Target=_Blank>External Web Link</a>
 
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adub

New Member
Another breadboard!
<A href='http://www.freewebs.com/adub/cratered.jpg' Target=_Blank>External Web Link</a>

It was being driven by IR in that picture.

Nuts &amp; Volts a few months ago had one with a pic so I had to have one with a picaxe.

Notice the &quot;crater&quot;? My first picaxe over heated just a smite. [;-)]
 
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Wrenow

Senior Member
I am currently working on various projects for Radio Control Model Warship Combat. Think Battlebots on the water with a WWII theme (common scale is 1/144, yielding ships from 2-6 feet long, firing up to 1/4&quot; ball bearings). See <A href='http:// www.ntxbg.org ' Target=_Blank>External Web Link</a>. or, for a more complete introduction, the introductory article from the December, 2005, issue of Servo Magazine <A href='http:// ftp://anonymous@rcwarships.org/servo20051rcmw.pdf ' Target=_Blank>External Web Link</a>

One of our members has already installed a PIC based microcontroller system for various ship functions. Another, on being introduced to the Picaxe, has totally redesigned his automatic pump switch system around the 08M, and is working on armament switches. I am working on a fire control assistant from 3 different directions, including a controller system. And a speed trap.

Not a whole lot to post yet, as we have only just begun. But, the Picaxe looks like a natural in robotics to us.

Wreno
 
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jpyle1

New Member
Been working off and on with home made 2 wheel balancer platform, servos, 28X, L293D, seperate power supplies. I am currently using a 5k pot with &quot;walking stick&quot; for sensing. Have tried a couple other methods, but seem to have hit a wall with speed of processing, and my poor coding skills. It balances, but I am still studying coding for averaging (rough PID) for motor control. I`m better at hardware than code, but still trying. Pictures are at http://s154.photobucket.com/albums/s249/jpyle1/? . Have one balancer other started with bigger motors and more power, multi-axis sensing.
 
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Rickharris

Senior Member
We make about 100 a year at a cost of about &#163;7 each - amazingly the motor gear box is the most costly part at &#163;1:70. I have yet to find a cheaper + inconvenient module for school use.

A simple bump and go robot can be made in a couple of hours - We use a rectangle or circle of MDF as a base and make the body out of card. A micro switch for a sensor on the front.
 
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tarzan

Senior Member
Jo C

You can just see the tip of the other spoon on the opposite side in that picture. When they meet a ridge or indent in the floor they ride over them with ease. They work really well.
 
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johnwales

New Member
jpyle1 - I'm impressed that you managed to get a balancer working with a picaxe chip. Could you give more information as to how you did it?
 
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Rickharris

Senior Member
For balancing you could try something I have been playing with i.e. put a sail (in my case a square of thin card) on a vertical arm. it damps out a lot of the movement and allows more time to react. the bottom of the arm drives a pot - this isn't very successful- friction i think. I will go to a light sensor system next time i get it out to play.
 
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Rickharris

Senior Member
For balancing you could try something I have been playing with i.e. put a sail (in my case a square of thin card) on a vertical arm. it damps out a lot of the movement and allows more time to react. the bottom of the arm drives a pot - this isn't very successful- friction i think. I will go to a light sensor system next time i get it out to play.
 
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chipwich

Member
Rickharris, could you post the parts supplier or a picture of the finished devices?

I've placed a few picaxes in very low end hardware for fun. Tried a $1 toy electric car and it worked, though it only went forward and backward...
 
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manuka

Senior Member
Speaking as an educator,I'm in 2 minds about the motivational benefits of simple &quot;robots&quot;, as there are now just SO MANY cheap toy shop offerings that DIY versions often fail to interest. Here in NZ at least there's often just not the time (or budget)for high school level students to reinvent the wheel at this level either. Australian retailer Dick Smith Electronics offers a brilliant line follower robot kit at ~&#163;10 that's rather the local yardstick. These have of course come in for easy Picaxe hacking.

In contrast I've seen pre teens MUCH more taken with flashing a few LEDs, making tunes &amp; IR control -all on a versatile 08M.

Of course for serious Picaxe robots try Tarzan's $$$($) darling =&gt; <A href='http://groups.msn.com/picaxe/4x4rov.msnw?action=ShowPhoto&amp;PhotoID=3 ' Target=_Blank>External Web Link</a> Stan
 
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Rickharris

Senior Member
Chipwhich <A href='http://www.geocities.com/davidvwilliamson/balance.html' Target=_Blank>External Web Link</a> This was where I started - although this idea is slightly different in that it is mechanical but works!

I experimented in using the sail to drive a pot I could read for position. The stuff is packed away at present as I am in the process of rebuilding my workshop area, but if I fall over it ill dig it out.

Web site above is a god start and shows the general idea. Other picaxiable things there too.
 
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manuka

Senior Member
It's true - it's really true! See=&gt;<A href='http://c6jones720cybernetix.blogspot.com/2006_02_01_c6jones720cybernetix_archive.html' Target=_Blank>External Web Link</a>
 
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jpyle1

New Member
johnwales, I built the platform from aluminum algle with cross bracing. The servos are gutted to the motors only. The L293D is driven from the 28X (at 16Mhz) and I used the &quot;readadc10&quot; command reading the lever connected to a 5k pot with a controlled voltage reference. Seperate power supplies Picaxe - 3 AAA @ 4.5v--The servos run at 7.2v. with a little voltage overdrive there. The coding is crude,but it does manage to remain upright. I have used accelerometers (adxl 202 and adxl 311) with limited results. This is a test bed now, for improving refinements on a larger platform. I now have a dual axis gyro and 3 axis accelerometers, all analog output, on one board. The servos do BARELY have enough power to recover from a moderate angle disruption. This setup IS marginal, however it can be done. I am sure that with refining the coding, better input with gyro/accel board, and stronger servo motors it is acheivable. Right now, it has a &quot;jiter&quot; in some stages of balancing, but I feel this could be overcome.
 
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slurp

Senior Member
Just started the thread about my Low Cost entry for the Mini Sumo competitions, another PICaxe based Robot... that's here <A href='http://www.minisumo.org.uk/forum/viewtopic.php?t=187' Target=_Blank>External Web Link</a>

There's a few more pictures to add... including the breadboard that carries the PICaxe and pulls the other circuits together. I guess it's a little odd looking due to the size restrictions in the competition but I hope it's of interest.

regards,
colin
 
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sharbotic

New Member
i am using a basic stamp2(homebrew by phanderson) sending commands to a central 08, which sends information to drive 16servos to four 08m. no pics yet, waiting on my domain registration.

 
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Rickharris

Senior Member
Now this <A href='http://www.solarbotics.com/resources/static/bep/bep5_turbot.php' Target=_Blank>External Web Link</a> seem eminently picaxble.

In fact crying out for it. next project on the table!
 
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Rickharris

Senior Member
I have just noted Stan's doubt about Robots - All I can say is they go down a bundle here in the UK.

OK most students would rather have a Robot wars robot spewing flame and destruction - but everyone begins somewhere.

I do have a big version that I show them first to kind of get their juices flowing.
 
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Mycroft2152

Senior Member
&quot;Picaxe-ing&quot; the Solarbotic's Turbot should be trivial. Most of the BEAMish designs can be easily done with an 08M. Solar Engines too.

In fact, over on the Yahoo BEAM group the use of PICAXEs in BEAM circuits has been called SMARTBEAM. You can thank Wilf for that one.

Myc
 
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chipwich

Member
The picaxe seems ideal for BEAM robots. The ability to change behavior through a 3 pin header rather than hardwire a solar engine is incredibly powerful. What's the simplest robot that can be constructed?

I like the idea of a cardboard chassis like Slurp's! Was thinking of mounting the engines right onto the perf board on one built here.
 
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