Let's Make Robots!

Omni Wheels

Does anyone know where I can get omni wheels in the UK?

I'm looking for 40mm diameter, and the only ones I can find are at Active Robots, which seem horrendously expensive.

Ideally, they would be the red and black ones as in OddBot's post here http://letsmakerobots.com/node/6901.

Anyone?

What causes servo "jitter" and how can I cure it?

Edit    Sorry, should have read this first.

http://letsmakerobots.com/node/3541

Not sure I'll be able to implement fritsl's solution, though.

 

I have a humanoid robot, which has 16 original servos, plus I have added 2 standard servos in claws, and recently 2 more micro servos for the head.

These 2 micro servos occasionally get a bad case of the "jitters", not all the time, but intermittently.

There's hope for us newbies...

This bloke started 2 years ago, with similar to the Start Here Robot.

He's come on a bit since then.

Coming soon.....

....to a Forum near you. :)

 

No prizes for guessing what it is.

 

Not Robot but still awesome video.

If you have ever flown an RC Helicopter, you will love this.

Question about Picaxe Random function

 

I understand that the picaxe does not have a clock, and that the "random" function will produce numbers in a sequence between 0 and 65535 (not really random), but I have a question.

From memory, when I used commodore basic all those years ago, you could write something like rnd(9), which would produce a random number between 0 and 9 (I think that's right), so is there any way I can get picbasic to do the same. I want to switch, on and off, 4 led's in a random sequence.

Thanks in advance :)

I'm a little confused with pin numbers on the Picaxe 28 project board

I have a motor driver fitted to the board, and 2 motors connected to the 2 sets of motor pins. These motors are driven in the code using low 4 : high 5 : high 6 : low 7.

I have a servo fitted to pin 0, and some led's fitted to pins 1, 2, and 3.

This all works fine, and it does what I want.

There are "vacant" digital output pins, which are numbered on the board 4, 5, 6 and 7, which are the same numbers that the motors use.

Wait for button pressed before program runs?

 

 

I have just received my new Uno, and was wondering if there is a way to get the code that has been uploaded to it, to wait until the button is pressed before proceeding?

Which micro-controller etc should I buy?

As some of you may be aware, I'm still very new to this pastime, both with regards to electronics and programming, but have built a couple of bots which have been reasonably successful, using an Axon II Microcontroller, shown here http://www.societyofrobots.com/axon2/.

I am finding it extremely difficult to get on with the C language (I'd never even heard of it until about 3 months ago), but I do seem to be able to "read" basic fairly easily.