Let's Make Robots!

RoboGames Sumo

I'm still very new to robotics, and there's no way I could just build a sumo robot right now.

But when I said I wanted to run a marathon a couple years ago, I wasn't a runner, and I just worked my way there slowly but surely, and finished the race.  Moral of the story; I'm much more motivated if I have goals.

LM324 question...

So, playing with oddbots distance sensor, the subject of using an op-amp to beef-up the signal was raised... I got a lm324 and did a little looking over the data sheets and quickly found there are about 4000 different applications for this little guy. Does anyone want to suggest a schematic that would be best to amp-up a signal coming from a IR photo-transistor?

Modular robot kits

Is there any robotshop that sells modular robot kits? Like in the video. It would be fun to play around with punch of such modules. Although they are simple enough to build by yourself too.

Building Circuit Diagram Software

I have seen quite a few folks on here replying to others with circuit diagrams. My question is what software does everyone use/prefer? I know some use Photoshop or Illustrator. Anything else anyone would reccomend?


Omnidirectional Camera (using Christmas Bauble)

Take one Round Silver Christmas Tree Bauble circa. 60mm and one simple ordinary webcam camera.

Mount the Camera pointing up at the ceiling (or Heavens).

Place the bauble Circa. 150mm above the Camera and Hey Presto you have 360° field of View.

The arrangement can be reversed depending on "Point of View".


Ok its distorted but should be enough to detect IR signals (look at the ceiling light for example).

Stall Detection

Ok, here's my problem for you guys.  How do you use a MCU(Arduino, PIC, Stamp, etc) to detect if the bot has a motor stalled on it. I know it can be done, because I've read about bots that are bumperless and detect which motor(s) are stalled for collision detection.  Yes, I know you measure the amps that the motor is pulling, but how do you use the microcontroller to do it?


arduino functions

Calculon is discovering the wonders of arduino programming, and he is confused with the function (subroutine) action. He defines and declares a function, but nothing happens. Behold the simplified code:

void loop(){

   goMotor;   //call the goMotor function


void goMotor(){    //activate dc motor via h-bridge



Dirk the homeless robot


And more cool projects on Electric-Circus!!!

Xbee modules help

HI, well, the free day is arriving, so i thought i'd go to sprakfun and fill my cart.

what exactly do i need to have wireless COM betwen two microcontrolers, or PC, to micro controller, or even stand alone Xbee's?

I have these items in my cart:

Reading 5 analog sensors, with one ADC pin, would this circuit work?

well, as usually I have all ADC pins used up on my arduino, 2 of them are used by i2c, and the other 4 are used, 3 for line follower, and one for sharp sensor at the front.


I need more proximity sensors, and a new line follower with 5 qrd1114 instead of 3, for maze solving.

So would this work?













how-to LMR meet-up

Inspired by the 2 years anniversary text on the LMR front page, I got to wondering

What do we require to make a successful LMR meet-up in real life?  

Yes I know we're spread all over the world, and anything higher than a 2% show-up rate would be a unbelievable. But what kind of physical preparations would one need? A large conference room with enough electrical outlets, loads of tables, PA-system and presentation equipment, and short distance to a bar and a cheap-ish hotel.

What else?

Sharp GP2D12 and Object Detection

Hi all,


I'm trying to use 2 sharp sensors to detect an object which is placed near a wall (see pic). The problem with these sensors is that the readings will fluctuate even when it's static and if the distance is far, it is harder to differentiate the object from the wall.

the sensors are mounted on a moving robot. Any suggestions to detect the object?

Yet another PWM Picaxe question

I am programming my Mr Basic with Mr Basic moron driver. I use a Picaxe 28x1. It is a very basic setup indeed, with a small servo carrying a sharp IR distance sensor.

After reading many pages of manuals and LMR and example code of other victims, I ran into a wall. It's the dreaded "PWM and servopos don't mix" wall on picaxes.

Polymorph Plastic ( a thermal plastic with low melting point),robot diy parts needed!

Dear friends,

 We want to sale at low price as $15/kg, exclusive delivery fee, and you don't need  to pay import tax.

When robot programmers get board

Hi all,

I'm new here. I found this on Youtube and thought you might enjoy it.