Let's Make Robots!

Flying bots

I'm working on making my own Robot controlled helicopter. Is there anyway to calcute the wing length of the blade in order to lift the helicopter?

Discussion of object recognition with distance sensors

I would just like to open the floor to any thoughts on the code would take for a robot to do a sweep with a distance sensor and get an idea of what it was looking at overall. We have seen object recognition (edge finding) a couple different ways and code to send a bot to open areas. What I am wondering now is about checking distances at different points of the sweep and (here's the important thing) to figure out what it is looking at.


I really REALLY want one.... They're making them so that you can reprogram the whole thing and even put on different accessories... *drool*


hi all,

I'm new to this forum. And I am making a new robot that will have a "go to home" functionality....


Hondas new balancing personal transport.

Apparently its insides is a big secret but if you look closely you can see the machine actually moving sideways as it keeps balance.

I don`t know about you guys but as soon as I saw it I wanted to pull it apart to find out how it works, or at least turn it upside down and take a look at the bottom.

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.

MTR - A planetary surface exploration rover

My PhD work, from concept to implementation ;)

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:

Manual compile and upload

We decided to get rid of the Arduino IDE for our project, and switch to make/avr-gcc/avrdude. Sure, the IDE is great for beginners and those who write small to medium-small projects, but it's awkward to use with larger projects using lots of files and several people coding at the same time. And the PC our university has provided to us is quite slow so some stuff take way too much time.

The transition wasn't as easy as we had hoped for though, and it took a day to figure everything out. So to hopefully make things smoother for others, here's how we did it.





What's the best way of turning? We have 2 DC motors, one on each wheel. To turn right I was sending forward command to the left motor and backward to the right motor but I'm having diffculty to keep track. The min PWM to give first spin changes drastically in every situtaion.  We have a digital compass and and I'm thinking relying only to that for this decision but it would be better if I had a look up table with tick numbers of encoders for each desired degree.


 How do you do turns in general?


Self-Replicating Stationary Phototrophs

How many of you guys garden?

Wireless camera plus lcd screen

Ever since I have seen the land warrior system ( http://dsc.discovery.com/videos/futureweapons-land-warrior.html ) I have been thrilled and wondered how hard it would be to make a simple version for airsoft or paintball.

I just thought I would put a camera on an airsoft gun, helmet, or  something and then it would relay it to a screen preferably on a 2.5 inch screen so it is on the eye and portable. 

I would like to know if the wireless camera could keep up with the movement of someone walking for a half way decent image.

My equipment would be -

Picaxe servopos vs pulsin - why different?

For various reasons, I am trying to emulate the function of a servo control board, insofar as the application will be only for motor speed and direction control via one pin and a pwm input- essentially, I'm trying to make a tiny motor driver compatible with inputs via a picaxe servopos command.

(I think there's lot of other potential applications here, but this is where I'm at for now).



dagu wild thumper batteries



I think I'm gonna buy a dagu wild thumper chassis or make something like one... but I was thinking...

the  motors are 6.6A max each, there are 6 of it, so you gotta be prepared for 39.6A max just for the motors... and I think I'm gonna do my own H bridge from mosfets... but whatever... I was looking for battery options. I searched on hobby king for lipo batteries, and I found that the 5000 maH are one of the bests, also are like $17 or something, but I just calculated here: