Let's Make Robots!

Going to build a YDM!

'Going to build a YDM'

Bit ambitious as a first project, but I have 'some' background in programing.

Right now I am a student at University of Idaho. I am taking C++ and attend the ACM meetings. ACM is a group on campus that does programing challenges and is now dabling in robotics. They recently got an Arduino board, and it is my understanding that it uses C++.

This will be my first robot, except for a semester in high school where I programed a robot to navigate a maze using only a sequence of commands.

 Am I better off getting an Arduino board to learn on, than a Picaxe 28x1? or stick with the reccomended hardware for the YDM? I do no plan to scavenge the bot for parts later, I would buy all new for my second bot.

Also, I have sourced all parts for the YDM from solarbotics.com except the sampler board! It would cost me nearly $40 USD to get one from the source provided. Does any one know of something availible in the US that could be used? (within reason and budget! :p  ) 


I think I would build my bot with the slower GM3 like the YDM II, instead of the GM9 on the original. I figured out what they were using by watching the video's, the original YDM is faster! 

I also would like to put a downward looking IR sensor to detect cliffs if the Picaxe would have support for it. (looking at its specs, it has plenty of pins for extra goodies)


 Anyway! looking forward to bot building and programing.


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A few questions:

can I drive the pager motors (for the sticks) from the darlington driver?

also, can I pass the signal for the servo through the darlington driver? If I did that, couldnt I put a 330ohm resister on the signal wire?

I dont want to have to remove the Darlington driver if I dont have to. 

I'm also going to be driving a speaker, if I remove the Darlington driver, I'm going to have to make special circuits for all the digital outputs.


• You can drive the pager motors from the darlington IC, but only in one direction. You can use two channels from the darlington + 2 extra transistors to create an H-bridge to drive the motor both ways, but you may find it easier to just make a seperate H-bridge or buy a motor driver IC.

• The servo signal can be passed through the darlington, but you'll need to add an extra pull-up resistor, and the servo signal will have to be inverted somewhere either in the code, electronically between the PICAXE and the darlington, or between the darlington and the servo.

What type of speaker are you using? A coil speaker can be driven by the darlington, whereas a piezo speaker is better driven directly from one of the PICAXE digital outputs.

Made some progress on the WDM  "White Drum Machine" this weekend.


I hope cat5 works for the sonic range finder.. it it doesnt, its going to be a pain to put lighter wire in.

I miss read how many L293D motor controlers I was going to need =/  going to try and drive the head with a servo for now.

I have a question. Is it absolutly necessary to have a sperate power supply for the servo?

fun fun!


CAT5 wire works for just about anything that doesn't need more than a few amps. Servos don't need a seperate power supply, but they do usually need a solid 4.8-6V and not too much noise (a capacitor or two usually fixes that anyway).
Parts for the YDM are ordered!

Parts have been here for a while.. still in their box.

Got the picaxe out and played with it making beeps.. got it to play marry had a little lamb :p

I ordered a sheet of the 1/8 pvc board, I'll be making the body from that.


Anyway.. Thought I would give an update.

I hope to work on getting the body assembled this weekend.


Man! You must have a defective board because if mine ever played "marry had a little lamb", I would make it surely defective by busting it up and trashing it. That's Guaranteed Defective Now..............
A Yankee Doodle Ministry! Can I join?

Arduino vs Picaxe is a religious war. To many it can be boiled down to whether you want to program in C/C++ (Arduino) or Basic (Picaxe). Both have their relative merits and shortcomings. They are both both capable of about the same things. Here's one take on it. Here's 186,000 more ;) (sidenote; Rock On! LMR is the first two results for "arduino vs picaxe" on google!)

If you plan on leaving the processer in the bot you may want to look into the cheaper alternatives to Arduino (RBBB for example). They're effectively the same thing, program the same way, have the same capabilities, but can cost significantly less (in the long run) when you have multiple permanent installs. If you choose to go with Arduino that is.

Check Radio Shack for little recorder modules. You may also find old/dead/leftover/whatever toys that had sampling abilities that you can pirate stuff from. AllElectronics.com has a Saw III movie thingie that records and plays back audio for two bucks (+7 shipping) that can be hacked into use.

There is no real hard and fast plan for most 'bots around here. In grand Perl tradition, TMTOWTDI. Do what you like, make it your own, just be sure to have fun and take pictures.