Propeller-based Thermal Imager

2

Comments

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,691
    edited 2012-09-20 - 15:44:01
    No, it would not work under water, since water is virtually opaque to long-wave infrared.Here's what the absorption spectrum of water looks like:

    800px-Water_absorption_spectrum.png

    8-15 microns is the region where thermal imaging sensors operate.

    -Phil
  • Mark_TMark_T Posts: 1,981
    edited 2012-09-20 - 16:01:14
    Polythene is the usual thermal-IR-transparent material. Salt (NaCl) works too (used in IR spectroscopy for sample holders - water strictly excluded). IR frequencies match quantum transitions in rotational and vibrational modes for many molecules.
  • Bob Lawrence (VE1RLL)Bob Lawrence (VE1RLL) Posts: 1,630
    edited 2012-09-21 - 14:13:12
    @-Phil re:No, it would not work under water

    Thanks! for the info. That's a great chart. I found some additional info via Google . It could still be used for anything with a temperature that floats on water. Lots to think about. :)
  • maxgmaxg Posts: 2
    edited 2012-10-03 - 13:23:55
    Hi Phil

    I was wondering if you have done any experiments with trying to detect humans in an outdoor environment at say 10 feet or more?

    Also I was wondering if you had looked at Panasonic's Grid-EYE which is an 8x8 array and also is carried by digikey. Wonder how they compare in temperature resolution in the human body range.

    http://www.youtube.com/watch?v=wOTOQfU5Qgw&feature=related

    Max



  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,691
    edited 2012-10-03 - 14:01:42
    Max,

    Welcome to the Parallax forum! And thank you for the pointer to the Panasonic part!

    Frankly, I'm a little bit fed up with Melexis right now. They seem not to be interested in any but super high-volume customers and want to control who can get the part. But this is a real toss-up from a technical standpoint. The Melexis part has a much higher temperature sensing range than the Panasonic part (300C vs. 100C max). For static camera positioning, Panasonic's 8x8 array is the nicer aspect ratio compared to Melexis' 16x4. However, for mechanical scanning, some pretty neat things can be done with the Melexis array by orienting it on a vertical tilt. As to calibration and other matters, I can't seem to find a Panasonic datasheet that explains any software matters, but it would have to be easier to use than the Melexsis sensor with its fourth-power and -root computations. Mechanically, the Panasonic sensor is much more fragile than the Melexis unit, and its lens is more exposed to scratches.

    I'm beginning to realize that this is technology that can easily be repurposed for nefarious uses. As such, Melexis' desire to have control over its customer base, and Panasonic's coyness about providing a useful datasheet seem not so surprising. For the time being, until these issues can be sorted, this project is on hold I'm sorry to say.

    -Phil
  • Duane DegnDuane Degn Posts: 10,136
    edited 2012-10-03 - 16:15:51
    Frankly, I'm a little bit fed up with Melexis right now. They seem not to be interested in any but super high-volume customers and want to control who can get the part. But this is a real toss-up from a technical standpoint.
    I noticed Digikey no longer stocks the Melexis sensors. Darn.
    For the time being, until these issues can be sorted, this project is on hold I'm sorry to say.

    Double darn!
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,691
    edited 2012-10-03 - 21:19:17
    Bob,

    Future has no inventory, and they will be subject to the same restrictions as DigiKey if Melexis decides to enforce their pre-approval policy.

    -Phil
  • Duane DegnDuane Degn Posts: 10,136
    edited 2012-10-04 - 02:17:46
    Future has no inventory

    They did have two in stock when Bob first posted the link (at least that's how many they had when I first saw Bob's post). I'm pretty sure it was a forum member who purchased the last two units.:innocent:

    Thanks for the link Bob.

    I like to think I'm as good as the next guy at coming up with nefarious uses for my electronics projects*, but I'm having a hard time coming up with a nefarious use for these thermal sensors. Hopefully I can come up with some before my two sensors arrive.

    Oh, oh, I just had an idea. A heat guided robot/quadcopter to chase dogs off our lawn before the dogs have a chance of doing their business.

    *Such as using a laser to blind flies. (Blind flies are easier to catch and feed to my pet spider.)
  • maxgmaxg Posts: 2
    edited 2012-10-04 - 05:12:26
    Hi Phil
    I've ordered 2 of the Panasonic Grid-EYE parts from digikey - but like you am having trouble getting useful info from Panasonic. I'll let you know how I do. They claim that a reference design with source code is available for their demo using an Arduino. Getting it is another matter.
    This Japanese trade show demo is impressive in what can be achieved with interpolation and other image processing applied to an 8x8 image
    http://www.youtube.com/watch?v=r5wTIaE1Fsg&feature=related

    When you said
    "neat things can be done with the Melexis array by orienting it on a vertical tilt", did you mean tilting it such that the pixels in each column are 1/4 .the row spacing from the previous column so that in scanning you would effectively have 64 rather than 16 separate vertical pixel locations?

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,691
    edited 2012-10-04 - 08:00:58
    Duane Degn wrote:
    I'm having a hard time coming up with a nefarious use for these thermal sensors.
    Heat-seeking missiles.
    maxg wrote:
    When you said "neat things can be done with the Melexis array by orienting it on a vertical tilt", did you mean tilting it such that the pixels in each column are 1/4 .the row spacing from the previous column so that in scanning you would effectively have 64 rather than 16 separate vertical pixel locations?
    Yes. :)

    -Phil
  • SRLMSRLM Posts: 5,045
    edited 2012-10-04 - 08:44:14
    Duane Degn wrote: »
    ...I'm having a hard time coming up with a nefarious use for these thermal sensors...

    Not as good as Phil's, but you could use them to see if anybody is home before robbing a place.
  • John AbshierJohn Abshier Posts: 1,111
    edited 2012-10-04 - 13:57:45
    The restriction is probably a case of "lawyer craziness." Everything can be used for good or bad. Well into the later part of the 20th century, IR guided antiaircraft missiles used sensors with one sensor element (pixel).

    John Abshier
  • Bob Lawrence (VE1RLL)Bob Lawrence (VE1RLL) Posts: 1,630
    edited 2012-10-10 - 18:33:52
    re:
    Thanks for the link Bob.

    No problem. Hopefully they will re-stock. Just to see what would happen I ordered 1 on the weekend and got this message back today

    "
    In reference to your above online order:
    Part# MLX90620ESF-BAB-000-TU is on backorder. We have place an order with the supplier for you, but they have not confirmed the commit date yet.
    "
    We'll see :lol:
  • Bob Lawrence (VE1RLL)Bob Lawrence (VE1RLL) Posts: 1,630
    edited 2012-10-27 - 07:37:57
    re:
    "
    In reference to your above online order:
    Part# MLX90620ESF-BAB-000-TU is on backorder. We have place an order with the supplier for you, but they have not confirmed the commit date yet.
    "

    Dear Robert Lawrence,


    Your order number 78840178 for Future Electronics has shipped.
    Listed below is a summary of your shipping and tracking information.


    Great! I really didn't think that I would get one.

  • LeonLeon Posts: 7,620
    edited 2012-10-27 - 08:29:52
    I just checked the Future web site and they don't seem to have any stock:

    http://uk.futureelectronics.com/en/Search.aspx?dsNav=Ntk:ManufacturerPartNumberUpshiftedSearch|*MLX90620ESF%2f-BAB%2f-000%2f-TU*|1|,Ny:True,Nea:True

    That might just be Future UK, of course.
  • Bob Lawrence (VE1RLL)Bob Lawrence (VE1RLL) Posts: 1,630
    edited 2012-10-29 - 16:08:54
    Leon,

    When I first tried to ordered I got the same response(see my comments about that a few posts up the page). I just ordered for the fun of it and to see what would happened. I was surprised to get the" It's shipped notice".
  • Bob Lawrence (VE1RLL)Bob Lawrence (VE1RLL) Posts: 1,630
    edited 2012-10-30 - 16:07:20
    Mine showed up via FedEx today. Now what? LOL
  • Tracy AllenTracy Allen Posts: 6,504
    edited 2013-01-02 - 17:12:27
    Hi Phil,
    I wonder if you've pursued this further? I see that Future currently has over 100 in stock. Today I was talking with people who are interested in having something like this attached to a prop-based system, fixed location, for detecting hot spots within the field of view in a room.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,691
    edited 2013-01-02 - 17:51:33
    Tracy,

    Thanks for bringing the Furture inventory to my attention!

    As long as sales of the sensors and the resulting modules don't have any strings attached by the vendor or by government entities, I'm interested in pursuing this further. I shall have to investigate once more to see what the conditions of sale are going to be.

    -Phil
  • Tracy AllenTracy Allen Posts: 6,504
    edited 2013-01-03 - 10:48:52
    I was able to place an order and am looking forward to trying it. The only restriction that came up was the usual boilerplate export cert:

    To remain in compliance with the UN Security Council Resolution 1540, the World Trade Organization (WCO) Framework of Standards to Secure and Facilitate Global Trade, U.S. Export Administration Regulations, the Trade laws of the European Union and any other applicable trade law, Future Electronics requires the following certification:

    This is to certify that EME SYSTEMS, at 2229 FIFTH ST., BERKELEY, CALIFORNIA UNITED STATES, 94710 will not transfer, export, re-export, resell, or otherwise make any product purchased from Future Electronics available for any of the following prohibited end uses or end users:
    1. The production, manufacture, design, development or use of missiles (including but not limited to space research), chemical or biological weapons or nuclear applications including but not limited to, nuclear explosive activities; un-safeguarded nuclear activities (including but not limited to nuclear power applications), or safeguarded and un-safeguarded nuclear fuel cycle activities including chemical processing of irradiated special nuclear or source material, production of heavy water, separation of isotopes of source and special nuclear material, or the fabrication of fuel containing plutonium.
    2. Any party/persons denied, debarred or sanctioned by any of the countries who have export/import authority over the products purchased or ordered by EME SYSTEMS from Future Electronics.

    In addition, EME SYSTEMS will not export/re-export, directly or indirectly, any products or technical data under this agreement to any country for which an export license or other government approval is required, without first obtaining such license or approval from the appropriate government authority.
  • Duane DegnDuane Degn Posts: 10,136
    edited 2013-01-03 - 11:44:52
    I didn't have any trouble when I ordered the MLX90620 from Furture, but when I ordered a couple Panasonic "Grid Eye" sensors, I had to fill out some sort of end use form.

    I had to agree not to use it in an unmanned aircraft. While my initial use was for detecting people in a ground based robot, I had hoped to add some of these sensors to aircraft for monitoring heat lose from buildings using a remote controlled aircraft. I suppose that application is out for now.
  • LeonLeon Posts: 7,620
    edited 2013-01-03 - 11:49:57
    Future UK now has them in stock for £46.11 each.
  • ElectricAyeElectricAye Posts: 4,561
    edited 2013-01-03 - 13:57:08
    .... 1. The production, manufacture, design, development or use of missiles...including but not limited to, nuclear explosive activities...


    Huh? Wha? Hey, wait jest a gosh darn second! I thot the 2nd amement lets me do whatever i darn well please!

    raygun.JPG 7134674_dr-horrible-and-the-death-ray-dr-horribles-sing-a-long-.jpg
  • Duane DegnDuane Degn Posts: 10,136
    edited 2013-01-03 - 14:04:35
    This is what the "Grid-Eye" agreements says:
    By signing below, I am acknowledging that these products will not be used by the above
    mentioned customer or end user directly or indirectly for:
    Development, manufacturing, use or storage of weapons of mass destructions. (Nuclear
    weapons; chemical or biological weapons, or their dispersal devices; or missiles or unmanned
    aircrafts capable of carrying these weapons)
    Development, manufacturing, use or storage of nuclear materials research of nuclear fission or
    manufacturing of heavy water.
    Actions of organizations entrusted by military or defense ministries
    1. Development or manufacturing of chemicals
    2. Development, manufacturing, use or storage of microbe or toxin
    3. Development, manufacturing, use or storage of missiles or unmanned aircrafts
    4. Development, manufacturing, use of conventional weapons

    So am I breaking the agreement if I have RC airplanes stored in my garage? Or only if I use the Grid-Eye to check the temperature of the stored airplanes?
  • NWCCTVNWCCTV Posts: 3,629
    edited 2013-01-03 - 16:22:23
    It seems to me if you are not building anything that will carry a WMD you should be fine. Get a Business license and call it R&D like the rest of us!!!!
  • mindrobotsmindrobots Posts: 6,506
    edited 2013-01-06 - 07:22:04
    I'm not a lawyer (thousands breath a sigh of relief) but I would take the enumerated items to apply to "Actions of organizations entrusted by military or defense ministries" - if you are not one of those organizations, you can use it for the purposes in 1-4.
  • ctwardellctwardell Posts: 1,705
    edited 2013-01-06 - 07:57:35
    Huh? Wha? Hey, wait jest a gosh darn second! I thot the 2nd amement lets me do whatever i darn well please!

    raygun.JPG 7134674_dr-horrible-and-the-death-ray-dr-horribles-sing-a-long-.jpg

    Someday, when some jack booted thug has his boot on your throat, or you're being loaded into a cattle car, you might just wish you hadn't been so flippant regarding the 2nd amendment.

    C.W.
  • mr23mr23 Posts: 21
    edited 2013-01-18 - 21:12:17
    http://www.kickstarter.com/projects/andyrawson/ir-blue-thermal-imaging-smartphone-accessory

    FYI. Uses the Melexis. The project is already funded, I was a backer. Thought some here might be interested in the information available from the project engineer/owner.

    Update: There is a Mu Thermal Imager over on indiegogo. Someone guessed it uses a sensor from ULIS in France

    comparison:
    KS - open source hardware and software
    indiegogo - closed source

    KS - -20 to 300 ˚C
    indiegogo - -66 to 140 C

    KS - 16x4 pixels resolution
    indiegogo - 169x120 pixels resolution
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