Let's Make Robots!

Help me come up with a more clever way to detect opponents



I've built a minisumo-robot for a competition this saturday(http://www.robotchampion.se). It works quite ok, but I feel that my opponent detection is somewhat unoptimized.(Don't worry, I'll make a post with videos, pictures and such when the competition's over, no time for submissions right now, mah code needs optimizing!)

Right now I have two Sharp IR-sensors looking forward giving me a viewfield of about 120 degrees. I have an if-statement that turns left if the right sensor is closest and vice versa.

Axle sizes

Hello fellow robot-builders!


For my next build it seems I migh have to do my own gearbox, I think I've worked out how to build it almost completely. The last issue I'm trying to figure out while I'm still in the planning stage is axles sizes and couplings. What is the best way to increase the diameter of an axle? Ideally, I shouldn't have to, but it all depends on what things I can get my hands on(I'm going for a one stage 30:1 reduction with a worm gear, since it doesn't take up much space and has builtin locking/braking).


Subsumption based robots

An awesome presentation on subsumption-based robots by David Andersson, it's a bit long, but it's totally worth it.


What range sensors should I use?

Hi fellow LMRians!


I'm starting work on a 3Kg sumobot quite soon(gathering parts at the moment, going to do it right and have everything before I start building this time).

Gearing Up, FIRST robotics challenge

Found this while searching for documentaries about robots;

http://www.youtube.com/watch?v=vytVIv-Rbx4 Part 1

http://www.youtube.com/watch?v=Go7GW7ef2U4 Part 2

http://www.youtube.com/watch?v=PPgXdktfiFc Part 3

http://www.youtube.com/watch?v=RocQrZ3pZXk Part 4


It's about the FIRST robotics competition, quite interesting.

Motor driver design ideas

I've decided to rebuild my L239D based motor controller a bit since A) it looks like crap and B) it uses to many pins and C) can't handle larger loads.

The plan is to piggyback two SN754410 instead of one L239D and add a tristate switch with transistors for the HIGH/LOW part.

The first question I have now is although the SN754410 is pin compatible with L239D, can I just mount two on top of each other and get 2x1A?

Swedish National Robotics Championships 2011



I thought I'd just inform you of the swedish national championship in robotics. There will be sumo, minisumo and a penthatlon. It will be held at the 9th of april in Gothenburg.

I'm going to participate in the penthatlon with the robot I'm building right now, I haven't posted any pictures of it yet, they'll later today. 

The penthatlon is made up of five parts(duh); maze solving, line following, terrain track, collecting cans and "show off". 

Any fellow LMRers(?) from sweden perhaps would like to meet up and share ideas?