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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Who me document? No - not on this experiment specifically....  but many have.

Google it  and the first entry will be one of the sources I used for.   It's pretty effective - I suspect most people's largest issue is getting the raw data from the webcam, or if not raw - something to work with.  Depending on the OS this could vary - e.g Linux - no problem.  But if you use a software package like OpenCV you can get that data, in addition to all their other wonderful functions .. optical tracking, face recognition, motion detection... yattah yattah...

I have been more interested in stereopsis - and the idea ambient light can be used (along with feature tracking .. etc) which I HAVE been documenting....

to their credit OpenCV has stereo functions, but alas they are kind of tweaky, subject to "tearing", and require way to much processing and calibration ... I'm working on amazing alternative solution - low processing - and requires a single cam similiar to monoSLAM ... (Oh I do believe I have drivelled on...)


Thanks for the details, drivell accepted.

It reminds me of some experiments i made years (er hum many years ago when the first memory chip came out) , i can just remember that the first memory chips had sealed windows which you could remove and use as multi cell light detector - though the positioning of the memory cells where not to linear.

My respect for you has just increased many fold !

Gareths Sharp dies through PEBKAC mistake

All this means, is that you have passed one of the many "Trial By Fires" on the way to ultimate enlightenment - and that all IC devices are created with magic smoke inside..  I have plenty of these soulless creatures.. When you have learned to put the smoke back in, you have reached Nirvana !


BTW, I think I've found a sensor which very sensitive to ~650 nm

 LOGIOPTICAL.jpg Although it appears to "take a picture" of a reflection to a CMOS sensor -  I'm guessing that laser tape measures are nothing but glorified optical mice with some dsp calcs.  I think this requires some experimentation Eh What, Mr. Holmes?

Your humble,


I rememberreading about hardware hacks on these. Using the sensor as a very coarse camera or scanner. I believe it was 16x16 pixels. Anyway, the point being: the protocol sent out by the mouse is well documented on the Net somewhere. As are the optical properties of the assembly.

A 16x16 array is indeed very common, but you can get optical mice with higher or lower resolutions, different spectral sensitivities, etc. As rik has mentioned the datasheet for the parts are easy to find, there is a wealth of information available on optical mouse sensor ICs.

Looks like some of the pictures I take?   Hmm .. the possiblities are growing !

I have been the whole day daydreaming re:- your mouse idea........ then bingo  a  "Wii" idea came.

WII.jpg All you have to do is remove the stupid IR filter off the front.

and it can see not only Lazer but also reflected lazer.

Now wot to do with the codeing - heck no time holidays coming.