Let's Make Robots!

Trouble connecting Vcc2 to SN754410

I've tried looking around a bit and expect this to be a fairly basic question, but nonetheless I still can't get it to work. Basically I have an arduino connected to a SN754410 motor driver powering a lego motor. This all works fine until I try to use a second power supply (9V battery in this case) instead of the arduino's 5V output. Here's the current setup:


SN754410 Test LayoutNote that the arduino is running off of USB power.

How to connect stuff?

I recently had the great idea of building a robot.


So I went and bought this:


and a PIC 18F4550 IC to go on it, as well as some wires and a couple geared motors and a servo. So... How do I connect all the stuff together so that it works?


I have never done anything with electronics before in my life.

Computers stolen from DAGU

Just letting every one who has placed an order recently with DAGU know that their order will be delayed as our office was broken into again and most of our computers were stolen along with the work van. Since Claudia's computer was one of the stolen computers you should email her again with any recent orders made using the subject:"ORDER MADE PRIOR TO BREAK IN" so we can check it against what has been sent. We will have new computers up and running soon so there shouldn't be too much delay.

Sorry for the inconvenience,
OddBot (aka Russell Cameron)

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:

P3AT Mobile Robot

I'm now working with P3AT mobile robot, I'm assigned to plug in USB webcam into the robot, then capture the video, and connect the video to another laptop via VNC Viewer software. But the problem that I am facing now is once I connect the webcam, I cannot connect with the other laptop through VNC. The connection can't be established. How should I do?Thanks.


A different method of propulsion using gears

Servo motor

How to control a servo motor (2) by just twisting or turning the other servo motor (1) or potentiometer using hand?

The servo motor 2 will follow the movements of the servo motor 1 or the potentiometer.

Not necessary to use a servo motor for the servo motor 1, just any solution that would perform what is shown in this video (http://www.youtube.com/watch?v=zZwnyZPkylk&feature=related).


Does LMR need a good prototype board?

Im thinking with all the things we make, a lot of times on a prototype board or some perf board, we at least deserve a good one that we agree has the layout we want. I think something we designed might be more useful than something like this http://www.mcmelectronics.com/product/21-4580&CAWELAID=220241321 or these http://www.sparkfun.com/commerce/categories.php?c=149 . Not to mention i prefer proper PCBs with traces and a solder mask instead of the exposed copper.

Not Robot but still awesome video.

If you have ever flown an RC Helicopter, you will love this.

Arduino IDE - what's wrong with versions 0019 onward?

Ever since the release of the new Arduino PCB's there have been at the time I wrote this 4 new versions of the IDE. As far as I can tell none of them work very well. All of my code is written on version 0018 and works fine. Open the same program in later versions such as version 0022 and you get an error when verifying the code.

Here is an example.

Connecting Multiple Microcontrollers

I was wondering if it would be possibly to connect multiple microcontroller IC's by there I/O ports?

Occupancy Grid Programming Help.

With much help and inspiration from Gareth and Grog (and others) I have a working Lidar (wiicamera and laser) system. Currently, I am using a very low power laser (while checking the mail everyday for the good laser to show up) and getting about 16" of range. For now during testing this is just fine. Everything is just in a smaller scale, but proportionally, everything is equal.

Coaxial helis

I sorta got into "flying" robots recently and I have found answers concerning most of my questions, but there is a particular thing I don't understand about helicopters; how do the coaxial system work (I mean, how can I make one from scratch). I understand that each rotor cancels the other's torque, but how does all this mechanicaly work? Are the rotors dependant on each other for speed (I suppose that's not true because the heli turns probably by increasing torque generated by one rotor and decreasing torque on the other).

looking for two wheel driving formula with X, Y

I am using one joystick to control the robot. The range of value I fot from joy stick is 0~600 and the PWM to motor control is 40~140. So wheels will be nutrul around 95 as center point. 40 will go backward and 140 will go forward. This is what I have:

  int maxVal=140;
  int minVal=40;
  joyX = map(joyX, 0,600,minVal,maxVal);
  joyY = map(joyY, 0,600,minVal,maxVal);
  int speed_L = formula;
  int speed_R = formula;