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New proximity sensor, good fit for Propeller — Parallax Forums

New proximity sensor, good fit for Propeller

RaymanRayman Posts: 14,845
edited 2012-02-06 16:35 in Propeller 1
Just wanted to mention a new digital proximity sensor, Prox1...

Prox1_detail.png


It's based on the Osram SFH 7741 IR proximity sensor.
Has a range of 30 mm and a digital output.
Rated for 2.4 to 3.6 volts, so it's perfect for the Propeller.

The output is open drain with 100k pullup resistor and abs. max voltage is 6 VDC, so I actually use them at 5 VDC on a servo header and it works fine.

Comes with a servo extension cable that you can cut in have and then use either male or female end to connect to your circuit.

I'm using four of them on a Sparkfun Magician chassis bot. Three for wall avoidance and one for looking at the floor:
4xProxy1.jpg
Prox1_detail.png
619 x 430 - 274K
4xProxy1.jpg
1024 x 768 - 80K

Comments

  • ElectricAyeElectricAye Posts: 4,561
    edited 2012-01-27 11:29
    Rayman wrote: »
    Just wanted to mention a new digital proximity sensor, Prox1...
    ...

    Looks great! I'm especially impressed by its "aspect ratio" (or whatever it should be called), how far it can detect vs. it's overall size.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-01-27 12:14
    After looking through some of the literature, I think these have a range of about 3cm. Is that enough to keep from bumping into wall?
  • RaymanRayman Posts: 14,845
    edited 2012-01-27 12:18
    Yes, check out this video (from this thread):

    Watch Merlin robot use optical sensors to avoid hitting the wall:
    http://www.youtube.com/watch?v=N-JmOayldJ4
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-01-27 12:29
    Rayman wrote: »
    Yes, check out this video (from this thread):

    Watch Merlin robot use optical sensors to avoid hitting the wall:
    http://www.youtube.com/watch?v=N-JmOayldJ4

    That's very cool!

    Thanks,

    Duane
  • Toby SeckshundToby Seckshund Posts: 2,027
    edited 2012-01-27 13:00
    I recently caught bits of an artical on tv about a model of a rats snout. it had loads of "wiskers" to do the proximity sensing and map out its enviroment. Unfortunately there was too much noise going on to catch any details
  • ElectricAyeElectricAye Posts: 4,561
    edited 2012-01-27 15:06
    Rayman wrote: »
    ...

    Watch Merlin robot use optical sensors to avoid hitting the wall:...

    Looks great. What about the sensor you have on the front and looking down? Does that avoid cliffs?
  • RaymanRayman Posts: 14,845
    edited 2012-01-27 15:19
    I think it could, that was the idea... But, my hardwood floor is a bad color for this...
    The full 3 cm range is for white. It's more like 1.5 cm or less for dark things.
    Anyway, it'd work to detect the floor if I moved it down lower, closer to the floor.
    Right now, it's more like an "object on the floor" detector...

    BTW: I think it would be good for a line follower too. White tape on my hardwood should work...
  • GeorgeCollinsGeorgeCollins Posts: 132
    edited 2012-02-06 13:57
    I just wanted to say that I spent this weekend testing these sensors at 3.3v and 5v and they work very well. They were easy to set up and quite reliable. I plan to stick them on a robot and hopefully I can post a video. Thumbs up!
  • RaymanRayman Posts: 14,845
    edited 2012-02-06 16:35
    Thanks George! Glad they're working for you.
    In hindsight, I wish I had the output pin on the outside, so it'd match a servo header.
    May have to change that for the next batch...

    I still think of 5V operation as a bit experimental. Seems to work fine and it's below the "Absolute Max."
    Just a little worried about lifetime... I should power one up 24/7 just to make sure it can take it for a long time...
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