Let's Make Robots!


Avoid Obstacles, Search for charging station when battery is low.
Using a
This robot normally goes around avoiding obstacles and (sometimes) edges until its batter drops low. Then the robot goes towards a 38khz pulse instead of away from … Read more

Basic Triagulation Positioning System

3 Friends and I are building an autonomous tennis ball collecting robot for a 4th year design project for our undergrad.

We need a way for the robot to keep track of its position on the tennis court (in doors) and we are thinking of using 2 beacons to emit signals with a receiver on the robot. Has anybody done something like this before? Has anyone heard of pre-packaged solutions that do just this? A USB module would be ideal (we are using a netbook to control the robot), but we are not at all opposed to building the positioning system from scratch. 

IR Homing Beacon?

I'm looking to build an Beacon, IR or otherwise, that a robot can see and simply drive to. Pretty much like a docking station for the robot to be recharged or a robot that follows you. (unless that's something different...)

I did a few searches, but I've only come up with robots that use a beacon and not how to build the circuit and write the code.

Any help? 


Edit: 8.31.09


I don't know if this helps, but I'm pretty much looking to build what CtC did here: http://letsmakerobots.com/node/6499

Forget making a LED blink. how do you even get it to turn on? This is a walkthrough for making an LED turn on and off at will, in a small beacon for a robot's … Read more
sits in one spot and does nothing for the moment
Using a
Basically this tank was gutted and is being rebuilt with sensors and a new brain. I've posted info on this tank and how cheap it was to aquire, so now this is going … Read more

bluetooth com and processing language rig

These are the source files related to the setup I mentioned in CTC's post about wireless serial com.


Reposting info on the setup just for ref.

Alrighty, ctc, got the rig working. The setup is the following:

<ir beacon> transmitting byte sequence from 1-9

<relay station> picaxe 8m with ir receiver showing correct data in the debug window.

Transmitting the byte sequence received from ir beacon via bt to my desktop running the processing code.

mini ir beacon

So this is the mini ir beacon I've had mulling around but never got around to building one....or finally built it. I'll post the current code for this in a bit.

The circuit is pretty basic in that it just uses a picaxe, an ir emitter, led, some resistors and a npn transistor. Ialso wanted to keep it small(hence the mini) so decided to use some lr44 batteries to get around 4.5v out. The battery holder was fashioned out of some 18ga colid copper wire which does a great job of holding things together.

 The setup

RC RF directional beacon

I am still wondering if it is possible to create a simple, cheap, fairly accurate, directional beacon for outdoor use. And I keep thinking I should try to re-purpose an RC transmitter. So here it goes:

Would you deem it possible to create a directional antenna for an RC transmitter?

Would this antenna be able to rotate? Fully continous, or just 360 CW followed by 360 CCW?

Which RC system would you consider? There are so many frequencies in use. And modulation types.

High Frequency beacon

Hi guys

I'm working on a lawn mower. I'd like it to precisely know its position in order  to optimise its travel.  As it is working outside and on a more than 500 square meters, the IR beacon (needs to remain in sight) , the GPS(not sufficient precision) won't fi my needs. Any idea like HF beacon ?