Let's Make Robots!

How to run low volt LED with high voltage?

I'm trying to put in a small indicator LED in my car that turns on whenever the brake lights come on.  I want to wire it to the same power line that the brake lights are attached to, so that whenever the switch is pressed and the brakes come on, that same power turns on the indicator LED.

Now, I'm aware I could just get a 12 volt LED, but I really don't want to do this.  It's not as much about functionality as it is about my personal learning.

Omnibot mk1 by Michal Zalewski

I came across a cool design for a robot that can turn it's wheels at the same time to turn in place or drive sideways. Take a look here:


The guy made molds for planetary gearboxes, levers, wheels and motor mounts. Here is an image:

LMR Robotic Online Football (Soccer)

I decided to resuscitate the LMR soccer game using my new µBipedino robots. The game will play as it was originally discussed, just with different players. These new robots can run around for about an hour on a fresh charge (when a Bluetooth module is attached), so the game will consist of 2 halves of 30 minutes each.

Robotic Bee Colony


I was out for the weekend and it seems there was a lot of talk on this subject. It happened that I had one of my bee hives swarm and I had trouble retrieving it. However, this gave me a thought of changing the theme a bit: Robotic Bee Colony. 

How, When, Damn it, Why do servos jitter?

I've had a lot of trouble with servo jitter lately, I seem so have solved the problem but I'm not sure why it has worked.

servos.jpgAt first I thought it was the power supply being spiked, no amount of decoupling capacitors solved the problem.

I thought it was software and although my code was improved, the jitter continued.

Because I was using optic sensors, I thought fluctuations in the light is causing my inputs to give false readings. Still no luck and I stubbed my toe in the dark.

Arduino Scan Function

This is for another project beside the LED cube i started on. (I messed up real bad so I'm moving on). I need to get my Arduino to run a scan function. But I need it to run only once in the loop. I need it to send variables to other functions. It's kinda hard to explain, so i'll map it out a bit.

void setup(){

All this good setup stuff...



void loop(){

Area mapping

I have (that is relative because I have not yet ordered my first parts from Robotshop) a PING ultrasonic sensor. I'll be having an arduino mini - though I'll no doubt buy something bigger after - and I wonder if I can efficiently make my upcoming rover (differentially driven, nothing special really) map it's surrounding area using a grid. Is it possible or will I run short on memory with the arduino mini? And more importantly, I need help with the code (I have 0 experience with code, though I have enough theory I guess...). Any suggestions are appreciated.

I am confused about how to use LiPo batteries

Hi all,

I am currently working on a new robot and I will soon have to choose a way to feed it with power.

I've been reading about LiPo batteries, but I am still confused about how to integrate this kind of power supply in a robot. Here are a few questions I have in mind :

Response time slow on Python pySerial, RPi, and Arduino orchestration

I'm working on learning Python and orchestrating my Raspberry Pi to be my bot's brain.  Currently, my plan is to develop an orchestration code between the RPi and Arduino+Motor Shield using good old UART and pySerial.  Right now, I've written rough code to cause the RPi to act as a fancy wireless shield.  It is suppose to capture key strokes and send them to the Ardy.  The trouble I'm having at this stage is with key presses not getting delivered to the Arduino quick enough.  Also, if the key is held down, the key is not repeated like hoped.

Test email service

testing the emain notifications

Atmega + camera.

I have thought about atmega + camera idea too, but for use on atmega not sending. I looked at CMUcam but it wasn't so low-cost as it was advertised (100$ it too much). I found http://www.robotshop.us/sfe-cmos-camera-640-480.html . It seems cheap, microcontroller friendly and so on. Only problems are - SMD connections, killer programming and impossible debuging.


So, all thoughts and good links are welcome.

How to reduce servo noise?

So it has come to my attention that like motors, servos too need capacitors over the power and signal lines. Well my question is exactly what value capacitor and on what servo pin. I looked online and could not exactly find it, maybe you have a link. I dont know if it is specific to what servo you have but here is the link to mine http://www.hobbypartz.com/topromisesg9.html

LCD03 and PICAXE 28 pin Project Board


Does anyone know how to connect a LCD03 to a picaxe 28x project board?

EDIT: I've already connected the LCD successfully to the board :D.

Robots charging robots

I've had a recent glut of "good ideas" recently and one might help along my swarm dream. I always wanted a bunch of little robots that could assist each other in some way. The aforementioned idea would take a Joule Thief running off of a fully-charged robot's battery pack and use it to give a dead battery on another robot a quick boost to help it get out of the dark and back to a better lit area (bots would normally recharge in the sun).