Let's Make Robots!

My suggestion

Beginners like me want to build the same robots on home page
I think there are few documents about how to build them !!
So could the authors  supply some instructions of building your
robots when you post pictures of robots on home page ??
hehe , Excuse me , English is not my native language !!

Sparkfun sensors

You have written in your post that you used a Sparkfun sensor in making your balancing robot. Is there any cheaper alternative to Sparkfun which can be used instead.I stay in India so i have order the sensor and its pretty costly for me.Could u please help out.please please.The Arduino Deumilanove board is cheap so i can buy that.Could u recommed a cheaper sensor which works with this board.Thank you


Ravi Srikant

Line follower on changing contrast

I am making a line follower using an ATmega8

Now the problem is the testing of line follower, there is a black line over a white surface and then after a while, there is a white line over a black surface....

The robot will make a start on any of the corners...so it is  impossible to tell whether it is a white line or black line...and also in middle, the contrast will change...

I have to make the program in such a way that it will detect the change in contrast and continue its work

I thot this can be done in programming part..so posted here...

picaxe 28x1 chip

hello all,

need to know that hoe can i connect picaxe 28x1 chip to picaxe 28 pin project board. 

IR Distance Sensor (not a sharp! wahoo) for my xmos project

 So I had an idea (because i i like building my own stuff) of an IR range finder very similar in fact to odbots attempt at a laser rangefinder combined with CtC's ir beacon. So a narrow beam IR LED is mounted on a servo or stepper (or several if more power is needed). A IR transistor (one of those TV remote receivers) is mounted next to it at a known distance inside a tube similar to that in CtC's design. The servo or stepper scans from pointing towards the sensor (near perpendicularly) outwards near parallel while the led is being pulsed at the appropriate frequency.

Custom Motor Driver Debugging

Hello LMR!

I built a motor driver, look: 


Cool isnt it? Of course it doesn't work as intended, but hopefully you guys can help me fix that. Lets take a look at the details first, and afterwards my problem.

Mindstorms Aircraft Factory

"25 RCX
73 motors
costs: 8000€
2000 man hours"

This is sick...

Picaxe LCD Direct Connection Problem

Hey There,

I've hit a snag on a project of mine. I've been trying to build a servo calibrator (to test a servo's limits and test them on robots before they're connected to the motherboard) which should operate by positioning a servo depending on the position of a potentiometer, and display the pulse rate on a 16x2 LCD. I've built one before, with an LED display and a single servo output, but this one should handle two servos.

Except it doesn't. I won't even handle one.  There's two major problems I've found which I'm looking for solutions to.

Step up issues.

sc014a11d9.jpgxI recently bought a step up from spark-fun. The "DC-DC Boost converter NCP1400-5V". I power it with a 3.7v li po battery but it seems to be dead so I powered it with apporx 3.9v. I had used it in my micromouse and I am faced with a BIG problem. You see, I

connected( all in parallel)