Let's Make Robots!

compass modules?

Does anyone know of a compass module that'll return heading as a voltage, rather than timed pulses or requiring an i2C interface? The qwerk board seems a bit limited in its inability to handle either of those, and the api doesn't support the quadrature encoders either so I'm trying to find a way to work out where the thing is facing!

Joystick and picaxe 28X1


Here is a pick of and old joystick from a 360 or ps controler,

I have 2 questions, the thigs on the side that sens the position are they potentiometer ? and would a chip like a picaxe or some other one be able to interpret the signal coming to it ?


Help with 18x Electric Vehicle code

I'm working on some code for an event in Science Olmpiad in New york, the code below should check input 2 for a high signal, then jump to sub Diselect, then check for the pins for the right combonations of inputs to then jump to the assosiated sub, the subs take a plse input from an optointerupt and record the length of the pulse to w0, it wil pulse the servo until w0 is equal to the assigned number.



Expanded PVC vs Foam Board

I got some Foam Board from Michaels yesterday and was looking up expanded PVC also to build my robot frame and body. They look almost identical online. Both can be cut with knives also. Are they the same thing? and if they are not the same thing would it be better to make the bot first with the foam board then use it as a pattern to cut the expanded PVC?


Thanks for your help! :)

LMR Plataform

I just recently resgistered for LMR. It called my attention the plataform is been used here. I have used wikis before but this look a bit different. Anybody could tell me wich plataform or CMS are using here, I am courious.



reading from a Sharp GP2D120


 Using an ATmega8, and i'm having trouble reading from my sharp GP2D120.

Here's the code i'm using, which is from the manual of my kit:


So I haven't built any robots lately because I am really busy. But, just a day ago a friend sent me a whole pack of transistors, resistors, and a heck load of ICs. There are about 10 types of ICs he gave. Each having about 20 for each IC. I was wondering if I could use these in any robots but they just are to complicated. I tried searching on google and I really don't get that stuff. Could any of you help explain some of these ICs? Here is the tour through all of them:


The SN74HC74N-

Robot with a personality

This little guy will track your face, and if you hold still long enough, it takes a picture and uploads the image to its own website!

I just love how smoothly it moves, almost looks like it has its own personality...

Its own site is here. Doesn't look like it's currently working, but still has info on the bot.

Batteries Series Parallel

A few questions to make sure I don't burn something up. I am playing around with different batteries and ways to make my bots last longer between charges. I want to ensure I have this right before I hook anything up.

First off lets assume I have 5 volts hooked up to a LED (max rated current of 30milliamps) using a 150 ohm resistor (5 volts divided by .03 amps = 166 resistor to keep LED from burning out).

Series: Lets say I take a 5 volt battery pack and hook it up in series making the total voltage 10 volts.