Let's Make Robots!

"LoMoR" - Lets Orientate & Map Our Robots (Sonar Based)

"LoMoR" - Lets Orientate & Map Our Robots (Sonar Based)

 Also Blogged as Mystery Object Here

My System Uses a LCD display to Map an area which is scanned by an Ultrasonic or IR Distance_ing transducer.

The Angle of the Probe is converted from polar Coordinate to Cartesian Coords and then displayed X,Y fashion on the LCD Display.

The System works pretty well i must say, however the "Extra" echos of Ultrasonic signal can be miss-leading.

What is super cool is being able to see what the Ultrasonic or IR sensor sees - it sees a lot more than you would think, or should i say Too much more!!

I am not sure what the overshot areas on the plot are yet. (maybe i have to mount the transducers sideways).

I mounted the Ultrasonic Transducer Vertically and it gave slightly better result - the plus point is the transducer can pivot better around itself.

Basic system is so:-

  1. Arduino - LCD walkthrough
  2. GLCD based display
  3. Data Sheet for KSO108B
  4. Ultrasonic or IR Distance Transducer connected to a servo.

My code_ing works this way :-

  1. Servo scans with attached Ultrasonic or IR sensor taking distance measurments
  2. From this you have the angle of the servo with distance to object
  3. Convert the Angle of the servos Polar Coordinates to (cartesian coordinates)
  4. ie x=cos(angle)*distance, y=sin(angle)*distance
  5. then you can plot direct to the display x,y
  6. Result is a visual map of your scanned area.

Video (1)  URL :- LoMoR with URM37 Ultrasonic Sensor (Film was made by my Son, voice over by me)
Video (2)  URL :- LoMoR with Sharp GP2Y0A02YK0F Infra Red Long Range Sensor

Video (3)  URL :- LoMoR with Maxbotix LV-EZ1 - Ultrasonic Long Range Sonar

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At last the WiiMote-Laser is taking shape you will find it by clicking the pictures.......


Looks like fun Gareth, but I don't have the gaming stuff (on the wagon now for 5 years)

What kind of wii thingy is that? (link?)

Unfortunately, I forgot to bring home the sacrificial rat, however, I have been doing pre-op(eration) experiments with a laser rat here.

The results are pretty interesting, I'll have a blog or something soon.   Its very sensitive and I think the laser coherence patterns - facke out the little CMOS camera on the mouse, in thinking that something is moving ..  Its a great laser pointer/cursor/mouse albiet the X Y is small (at the moment)

So much to tinker with so little time.

Just a couple of links to show capabilities.

Here is what i am using :- Wiki Wii

Its basically a camera built into the end of a bluetooth controller - able to pick up two spots of IR and relay the xy coords of both.

And Here is a guy who has done a lot of pioneering stuff with it  Johnny Lee

Its all controlled via Bluetooth which is extra cool for communications.......


I've done some investigation using the Wii IR camera and a laser pointer as a triangular sensor here. But this doesn't work very well.

  • Without the filter there were too many false echoes from other light sources or reflections.
  • The reflected light of laser pointer doesn't give a continous signal.
  • The detection range was only 50cm.
Maybe you find a more clever solution. Good luck.

BTW. Great idea your LoMoR  

Thanks for the Info - i have many tests ToDo before the laser work begins...........

...... Maybe i will have to find a "Filter" in the Laser light range to eliminate stray light ........

What i have noticed with Laser is the absorbtion into soft dark materials and the reflextion off shiney surfaces causes false readings... (Hmmmm have to build the servo setup first)

Ha ha, ho ho ...

I have found a sacrificial Test mouse/rat to dissect at my Laboratory...   bwah ha ha ha...  I thought it would be a LED optical mouse, but curiously it is a class I laser diode inside. Apparently laser optical mice are more common now than LEDs - this would make me believe that the compatibility (650 nm) between the key chain laser and this little guy is high.

The complexity is how to deal with reflected laser?

I've noticed when you lift up on the mouse - the amount of distance before the cursor dies is pretty small - if this could be blown outwards you could have a projected encoder?

The data on the wire is most likely going to be what it always has been, serial ints denoting direction an number of ticks.  The protocol might be even more standardized at this point.

I'll begin dissecting tonight... bwah ha ha - unless the wife hands me a honey-do list...

I am indeed honoured that a mouse will be die-sected by lazer surgery, in the interest of cloneing a Pioneering distance sensor.

How on earth did this pop into your "Cortex" , im impressed, cannot wait to hear the findings.

I have 4-days  in the mountians now (no net)- man i hope i do not miss anything..............so i will hold the scalpel for you in anticipation.

One very "old" LMR project: /node/1276.


Hey hes a cool one rik - (where was he hide-ing all this time).

Is that a 10 Gallon hat or are the ladies just pleased to see him........(and hey i detect some blue screen there .dumdadumdum).

Lucky i checked my mail before i chopped off my Ultrasonic to test a sharp.

I will try some cloth or thin foam.....

Perhaps something like this long distance Sharp IR would do the trick, however its minimum distance of 1m is a drawback. Plus I can`t find any information on exactly how much the beam spreads at its maximum sensing distance.