Shop OBEX P1 Docs P2 Docs Learn Events
What IR distance sensor to use ? — Parallax Forums

What IR distance sensor to use ?

whiteoxewhiteoxe Posts: 794
edited 2014-06-30 13:20 in Robotics
Well the motor driver took ages to arrive but im now about to fit that. Next step is the IR distance sensor, and I have no clue which i should get. Here is the ebay page Im looking at and they range in price from $2 to $20.

Could I get some suggestions please ?

http://www.ebay.com.au/sch/i.html?_trksid=p2047675.m570.l1313.TR0.TRC0.H0.Xir+distance+sensors&_nkw=ir+distance+sensors&_sacat=0&_from=R40

Comments

  • Bill HenningBill Henning Posts: 6,445
    edited 2014-06-28 13:12
    For near-sighted robots I use:

    Sharp GP2Y0A21YK0F IR Range Sensor - 10cm to 80cm

    For general purpose bots I use:

    Sharp GP2Y0A02YK0F IR Range Sensor - 20 cm to 150 cm

    I also use the following ultrasonic sensors:

    Parallax Ping, Seeedstudio range sensor (red), cheap HC-SR04's

    Hope this helps,

    Bill
    whiteoxe wrote: »
    Well the motor driver took ages to arrive but im now about to fit that. Next step is the IR distance sensor, and I have no clue which i should get. Here is the ebay page Im looking at and they range in price from $2 to $20.

    Could I get some suggestions please ?

    http://www.ebay.com.au/sch/i.html?_trksid=p2047675.m570.l1313.TR0.TRC0.H0.Xir+distance+sensors&_nkw=ir+distance+sensors&_sacat=0&_from=R40
  • whiteoxewhiteoxe Posts: 794
    edited 2014-06-28 14:00
    Thanks Bill, Ive ordered this 3 buck sensor

    http://www.ebay.com.au/itm/New-Arduino-Sharp-GP2Y0A2YK-IR-Infrared-Range-Sensor-With-Cable-/200940090233?pt=LH_DefaultDomain_15&hash=item2ec8f67379
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-06-28 14:01
    Erco posted a link to a good price on IR sensors here.

    Apparently the're the real deal at an amazing low price.

    I purchased some myself.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-06-28 14:03
    whiteoxe wrote: »
    Thanks Bill, Ive ordered this 3 buck sensor

    http://www.ebay.com.au/itm/New-Arduino-Sharp-GP2Y0A2YK-IR-Infrared-Range-Sensor-With-Cable-/200940090233?pt=LH_DefaultDomain_15&hash=item2ec8f67379

    Looks like a good deal.

    IMO, it's also a good idea to use an ultrasound sensor. The two types of sensors compliment each other. One can see things the other can't and vice versa.
  • whiteoxewhiteoxe Posts: 794
    edited 2014-06-28 14:07
    Will do it Duane !
  • whiteoxewhiteoxe Posts: 794
    edited 2014-06-28 14:14
    I was mistaken/confused, thought u meant PIR sensor, ive done searches for Ultra sound sensors and i keep getting ping sensors or pir sensors. Give me a bit more time, im sure ill find an ultrasound sensor :)
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-06-28 14:27
    Again, erco to the rescue. There are a lot of inexpensive ultrasound sensors on ebay.

    For other ebay bargains you can always check under "Things erco made me buy" in post #9 of my index.
  • whiteoxewhiteoxe Posts: 794
    edited 2014-06-28 14:39
    brilliant, thanks. I've ordered that as well.

    i just finished installing rasberian on to my sd card, now ready to put it in the pi A and set it up. im not sure what ill end up doing with it...drive a robot or connect it to a bank of relay switches ;)
  • Bill HenningBill Henning Posts: 6,445
    edited 2014-06-28 14:45
    You are welcome!
    whiteoxe wrote: »
    Thanks Bill, Ive ordered this 3 buck sensor

    http://www.ebay.com.au/itm/New-Arduino-Sharp-GP2Y0A2YK-IR-Infrared-Range-Sensor-With-Cable-/200940090233?pt=LH_DefaultDomain_15&hash=item2ec8f67379
  • Bill HenningBill Henning Posts: 6,445
    edited 2014-06-28 14:45
    Totally agreed.
    Duane Degn wrote: »
    Looks like a good deal.

    IMO, it's also a good idea to use an ultrasound sensor. The two types of sensors compliment each other. One can see things the other can't and vice versa.
  • xanaduxanadu Posts: 3,347
    edited 2014-06-28 15:08
    For the majority of scenarios I'd agree on the ultrasonic and IR doubled up. You can use the IR pairs at less than their advertised minimum distance ratings, you just don't get the smooth signal and it inverts. Then of course you need to program in a way to detect the inversion. On a robot going forward that isn't a problem with a direction variable set. On something stationary it would be an issue. I had my robot using them much past min distance spec, but now it can't tell if another mobile object is moving away from it, or it's past the IR min spec... I've been able to use that to my advantage and disadvantage, and would rather use the ultrasonic as a primary for a general baseboard bumping domestic robot. Even for an edge detector, in my testing the IR falls short of the ultrasonic. It's great you can run a pile of IR sensors on an ADC, four pins, eight sensors, can't go wrong with that.
  • ercoerco Posts: 20,255
    edited 2014-06-30 12:56
    I really like those Sharp I sensors, I've stockpiled ~30 for a project. They are an analog sensor and require an ADC to read them, but in a pinch you can use them as a digital proximity sensor, using the I/O pin as a comparator. The pin's TTL low/high threshold sets the distance, per this video. Hey, at least I used a Parallax ruler!
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-06-30 13:18
    erco wrote: »
    in a pinch you can use them as a digital proximity sensor, using the I/O pin as a comparator.

    I'm sure there are ways to adjust the trigger point with these sensors. A voltage divider would be an easy way to reduce the trigger voltage (I forget if the voltage if directly or inversely related to distance). I'd think some sort of capacitor to Vdd tied to the signal line would be used to increase the voltage trigger. I suppose by the time you go to this effort you might as well add the components needed to do a proper sigma-delta measurement.

    I haven't tried the sensors I purchased yet. I've been working on cool top secret stuff (hexacopter camera mount but don't tell anyone).
  • Courtney JacobsCourtney Jacobs Posts: 903
    edited 2014-06-30 13:20
    Has your question been satisfactorily answered? If so, can this thread be marked solved?
Sign In or Register to comment.