Let's Make Robots!


Wall follow and obstacle avoidance using Sharp IR sensors
explorer8_lmr.pde8.3 KB



 First of all, I want to congratulate you for a nice place you made here . I'm glad to find a such passionate and innovative group here.


I'll show you my little robot and how it change in past 2 months since I begin to work on it.

Where all begins...

Version 1, above picture, has simple obstacle avoidance using whiskers and 2 micro switches. CPU - Arduino 2009, drive - 2 hacked servos, power 3s LiIon cells.

Front view

 Step 2 was to made 3 colission detection sensors, using ultrabright red LEDs and photoresistors. They worked well, but chassis was too small and I decided to build a new one to accomodate new sensors.

Arduino, servos and power regulator were moved to new chassis, bigger weels and LiPo power pack added.

Chassis II



You can see on wood blocks guide lines I draw for LED and photoresistor channels.

This system worked  verry well, but was verry sensitive to ambient light so I decidedit was time to something advanced.

So a pair of Sharp GP2Y0A21YK0F is used for new detection system. I mount them  on an oscillating head, to cover a wider angle and to speed scanning process.











Work is in progress to smooth navigation and to develop more behavior modes. Meantime, enjoy the videos.






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Very well thought out robot, nice to see the progression. The initial wood block sensors, did they also output an analog voltage like the Sharps? They were very bright in the video. The scanning head is a cool addition. 

Though aesthetically speaking I tend to like the 1st version better. But in robotics function comes before aesthetics off course ;)

I very much like the shield you made and I'd love to see it up close. From both sides. In particular how you mounted the pins for attaching it to the Arduino and how you solved the problem of the weird spacing between pin 7 and 8...

Yes output is analog. I made a voltage divider from photoresistor and an additional resistor and read voltage over photoresistor.


 Leds are ultrabright 9000cd red Leds and they look nice in a dark room. Now I have to put some lights on front of robot, not decided what color yet.

 About the shield, I will post  pictures as soon I will be home.

Is made from perf board. On this board I solder angled pins on side facing Arduino and straight pins for servo and sensor connection o other side.

At the unusual gap between the two female heads on Arduino I just solder pins slightly moved to fit Arduino holes. Pics will tell more.

Looking forward to the pics :)

I take some pics, hope I caught relevant aspects. Questions are encouraged :)








































































Interesting way of solving the spacing problem. I've seen various ways of doing it. Some drill extra holes in the protoboard. You can even buy bended pin headers like this:


I chose this option...only I bended the pins myself and I couldn't find any of these female pin headers with the extra long legs which would be the ideal.

Anyway I may choose your way for my next shield. Though it does seem by the look of it to be a bit unstable. Would you say that the angled header are well attached to board? It's hard to see from the photos...

PS: And is that a camara with a heatsink around it?

Each pin of angled header is solder in 2 points and ensemble is quite strong. If you don't plug and unplug it too often, it's ok.

Is not a camera, is 5V voltage regulator  with heatsink. I thought servos will draw some power under continuos operation and I put heatsin, but is not the case. Regulators are just warm.

Well since I am planning to plug/unplug it rather often perhaps it's not the best way of making a shield. I think I'll go for bending the header pins again, but I'm still considering it.

Thanks for the info :)


Is quite a long time since I don't post anything here. But eXplorer have an arm now and today I'll show you how is working.

I designed it to be as little and light possible to fit my robot, it's task is to grab plastic balls and other small things.

The orientation toward the ball is still in progress.

And 2 short movies:



That is one awsome robot