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VL6180XV 0 to 100mm ranging with Time-of-Flight technology replace Pingers — Parallax Forums

VL6180XV 0 to 100mm ranging with Time-of-Flight technology replace Pingers

tonyp12tonyp12 Posts: 1,951
edited 2015-04-24 13:09 in General Discussion
If you need your robot to sense nearby objects I would not use old technology acoustic Pingers, but these instead ($5 each):

http://www.mouser.com/ProductDetail/STMicroelectronics/VL6180XV0NR-1/?qs=%2fha2pyFadugXfsHOY5xE%2fYiod6I2TZK3ntI2lXvVjWX2GFzU5nLmmQ%3d%3d

https://www.youtube.com/watch?v=2NHKga3V6xo

Comments

  • Heater.Heater. Posts: 21,230
    edited 2014-10-21 11:37
    Interesting.

    10cm range means most robots would be blind most of the time.

    Unless you mean close proximity, which of course could be useful.

    Can we get them? Who is going to make a break out board for them? Sounds like something SparkFun might be on to.

    Of course the price for a usable system for us normal people will be a lot more than 5 dollars.
  • tonyp12tonyp12 Posts: 1,951
    edited 2014-10-21 11:44
    >10cm range means most robots would be blind most of the time.

    They only guarantee 10cm, but if your robot is indoors and objects have at least 10% reflectivity you maybe get 20cm (something you have to test and calibrate)
  • jmgjmg Posts: 15,173
    edited 2014-10-21 12:51
    Heater. wrote: »

    Can we get them? ....

    Of course the price for a usable system for us normal people will be a lot more than 5 dollars.

    Mouser says 36 in stock, and 1: $6.25
    Summary says Supply Voltage: 2.5 V to 3 V
  • tonyp12tonyp12 Posts: 1,951
    edited 2014-10-21 13:26
    Could use a schottky diode to drop 3.3v to a safe range.
    or for 20cents you get a fixed and very steady 2.8v and if you actually want to measure distance down to single mm a ldo should be used.
    http://www.mouser.com/Micrel/Semiconductors/Power-Management-ICs/LDO-Voltage-Regulators/_/N-5cgacZscv7?P=1z0w7ypZ1yypt9y&Ns=Pricing%7c0

    Anyone could throw a pcb board together with diptrace and then order from oshpark for a few dollars, as you only need a few pull-resistors and caps.
  • jmgjmg Posts: 15,173
    edited 2014-10-21 13:49
    Beau Schwabe (Parallax) wrote: »
    I was doing experiments with this idea last week with much better success than 100mm....
    That's nice and simple, but would suffer from temperature and part-part variations, but with calibration would suit many apps.
    What part-types did you use and what frequency/distance tables did you get ?

    The ST part is low profile, with minimal beam forming, so 100mm is not bad for that physical form factor.
  • tonyp12tonyp12 Posts: 1,951
    edited 2014-10-21 13:52
    >much better success than 100mm....

    As they are targeting the mobile phone market (huge compared to diy robots), power consumption and miniaturization and that there is no need for more than 100mm in this market.
    That it also can handle being behind glass (cross talk) and also not going blind from a 0mm distance object is why the product they have is what it is.
    Yes, they should come out with 1meter version for us to use.

    I attached Diptrace breakout board RENAME to VL6180X.dip (as it is not really a zip file)
    VL6180X.jpg
    669 x 622 - 77K
    zip
    zip
    VL6180X.zip
    29K
  • Beau SchwabeBeau Schwabe Posts: 6,566
    edited 2014-10-21 13:57
    The part to part variations I'm not so concerned about as they would get lumped into the "FIXED" propagation delay, and temperature can be compensated for. The Delta of the frequency divider is what your after. The distance that I was getting was at least a foot down to point blank with a standard IR transmitter and receiver. The bias circuit I used for the receiver applied the IR receiver in a reverse biased configuration using it as a capacitor rather than a diode. Similar to the front end of this circuit ... http://forums.parallax.com/showthread.php/149216-DEMO-IR-Heartbeat-detector
  • BeanBean Posts: 8,129
    edited 2014-10-21 17:43
    Beau,
    What does the waveform look like going into the frequency divider ? and what is the "delta" of the frequency divider ?
    Sorry, I'm not following how the frequency divider "multiplies" the time-of-flight propagation ?

    Thanks,
    Bean
  • jmgjmg Posts: 15,173
    edited 2014-10-21 19:43
    Bean wrote: »
    Sorry, I'm not following how the frequency divider "multiplies" the time-of-flight propagation ?
    I think Beau there means more along the lines of the delta, and discarding the MSBs to focus on small changes.
    A frequency divider is a good way to remove cycle-cycle noise, and is easy to do in most chips.

    At 300mm/ns, and an example Base Osc value (set by device delays) of (say) 20MHz, will give ~ 1.33% dF / 100mm
  • DomanikDomanik Posts: 233
    edited 2014-10-21 20:09
    Beau,
    Your project looks like a lot of fun. I think its a pretty cool idea. How far along is it?

    Dom...
  • ercoerco Posts: 20,256
    edited 2015-04-23 06:37
    Sounds great, I just heard about these TOF sensors. I'll get one to play with. 10 cm range isn't enough for most robots, hopefully someone will follow up with a longer range version. For now, I'll stick with my big bag of $6 Sharp IR distance sensors.
  • ErlendErlend Posts: 612
    edited 2015-04-23 23:33
    Break-out board here for the lazy:
    https://www.tindie.com/products/onehorse/vl6180x-proximity-sensor-via-ir-laser-range-finding/?pt=full_prod_search

    Erlend
  • ercoerco Posts: 20,256
    edited 2015-04-24 07:14
    Erlend wrote: »
    Break-out board here for the lazy:

    There's good money in making breakout boards for the lazy (and rich) among us. This $8.48 (w/ship) jack sets the bar pretty high: http://www.ebay.com/itm/3-5mm-4-pin-stereo-audio-jack-breakout-board-eLabGuy-AJ-BO-V1B-/251922560894
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2015-04-24 12:52
    These would be great for near-contact applications, including "bumperless" bumper switches, and proximity sensors for grippers. IR reacts to many objects differently than sound, so they can be used as a sensor fusion backup with Pings. From the video, they could also to be useful for quadcopters, where it can be handy to know when you've left ground.
  • PublisonPublison Posts: 12,366
    edited 2015-04-24 13:03
    GordonMcComb wrote: »
    These would be great for near-contact applications, including "bumperless" bumper switches, and proximity sensors for grippers. IR reacts to many objects differently than sound, so they can be used as a sensor fusion backup with Pings. From the video, they could also to be useful for quadcopters, where it can be handy to know when you've left ground.

    They would be good for close encounter battery recharge docking stations.

    Forgot, erco already has that covered with IR stuff. :)
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2015-04-24 13:09
    erco wrote: »
    There's good money in making breakout boards for the lazy (and rich) among us.

    Considering this is how Sparkfun started, and as of a couple years ago were making $20M a year, at least, I'd say there's smart money making breakout boards. We may be lazy, but they be rich.
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