Let's Make Robots!

March Break 2011 - Robot Challenge

Line follower, sumo and finger follower behaviours selected via a mode button.

R/C robots are fine but I like autonomous robots best. For this March Break I wanted to host a "Build You Own Robot" party for my son and his two friends.

I've built small robots in the past so I thought I would challenge myself to come up with an easy to build, cheap robot "kit" plus code in two and a half weeks.  Here are the results.  A simple one board robot that has three modes; line follower, sumo and finger follower.  Full schematics, PCB and code (source and hex).

The cost is low since it uses many scavenged parts and cheap T-Pro SG90 servos that I found for $2.77 each.  There are things I'd change in a second version but not too bad as an intro.  You can make the board in under an hour using toner transfer.  Servos take about 10 minutes each to modify for full rotation and assembly takes about an hour. YMMV.


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Nice little robot! Welcome to LMR. I hope we'll see more of your work.

Great job on a three-in-one robot. I guess you're using a PICkit 2 for programming via icsp. What are those pins for behind the buttons? Did you use MPLAB to program it?


You really kept the component count down to a bare minimum!

I bet your son's friends are gonna come to your house a lot more often now!

Thanks for the encouragement.

Yes, I used a PICkit 2.  Normally I include an ICSP header on my boards but this is an exception since I didn't expect to reprogram the chips once the robots were done.  I use MPLAB in conjunction with the C18 compiler.  Before I used to use Mikroelektronika's compilers but I switched to MPLAB.  First I was doing a dsPIC33 project and the Mikroelektronika compiler for that family was still not mature.  Secondly the 2K limit on the free compiler was finally starting to pinch.  Otherwise nice products.

The two pins were intended as locations for two posts on which to swing some bumpers to depress the buttons.  But I ran out of time.  Instead I just used the pins to bring out GND and the line sensor signal for my scope during development.

I hope to be contributing more in the future.