Smartphone Multimeter Project

Discussion in 'The Projects Forum' started by jerrynz, Sep 11, 2013.

  1. jerrynz

    Thread Starter New Member

    Sep 11, 2013
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    Hi All,

    This is my first post here and I hope I'm not posting this in the wrong place.

    A team with which I am working are designing a low-cost, portable multimeter which connects to a Android or iOS smartphone. We are trying to gauge interest in such a product in the electronics community to determine whether it is feasible. The multimeter would have standard function as well as possibly an oscilloscope function. What are your thoughts on this? Any comments are much appreciated.

    If the device is produced, would you be likely to use a smartphone multimeter attachment? If so, what price are you willing to pay for one?

    What size would a multimeter need to be so that you would carry it with you as an everyday object?

    Thank you very much,
    Jerry
     
  2. strantor

    AAC Fanatic!

    Oct 3, 2010
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    1,988
    I wouldn't be interested. My only incentive to buy something like that, would be to save money, and I don't believe in skimping when it comes to multimeter. Also, for the things I measure (up to 1kV) I wouldn't feel comfy having that attached to my phone. The only other reason I can think of to have something like that is to save space, and if it were possible to make a DMM smaller than a phone, it seems they would already be that small. The fuses alone in my fluke are twice as thick as my phone, and I don't see how you could scale those fuses down and maintain the same properties.

    The only thing that might slightly entice me is if it had multiple channels and could record multiple different (ex. Ohms plus volts plus amps concurrently) readings on a strip chart display with really fast response, over long periods, and export that data to a computer. That's the only thing I which my fluke could do that it can't do. Oh, and it would be nice if I could take my cell phone with me while I walk off and let it do its recording. So that kinda renders the whole cell phone app/attachment pointless. If you could just make a standalone DMM that does this, I would be more interested in that than a cell phone attachment.
     
  3. wayneh

    Expert

    Sep 9, 2010
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    I'd have a little or mild interest in just regular DMM functions. I have several multimeters around, all of which were free at Harbor Freight, and are almost always available under $5. They work just fine for what I need (admittedly not much). I could imagine the display being really nice using a smartphone's screen instead, but that's a small thing. Not sure it's worth tying up the phone while I take measurements.

    The data acquisition aspects ARE interesting, notwithstanding the problem of tying up your phone. I have a LabJack U3 that connects to my computer and gives me data acquisition and control output capabilities. Having a mini version of that working with a smartphone would be interesting for many hobbyists and DIYers. But it's interesting because of the fact that a modern smartphone is a palm sized computer, and could replace a computer IF you had an interface. Not really a multimeter discussion anymore.
     
  4. jerrynz

    Thread Starter New Member

    Sep 11, 2013
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    Thank you very much for the input. We will definitely keep your feedback in mind.

    Jerry
     
  5. sirch2

    Well-Known Member

    Jan 21, 2013
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    It would have to be very small and cheap to be worth while, and it's not often that I find myself just randomly wanting a multimeter (as opposed to being somwhere where I have ready access to a multimeter). Even then I probably wouldn't have the phone attachment with me. If it was cheap enough I may just keep one in the car.

    Rather than a full-on multimeter, it may be worth thinking about just basic functions like continuity, contactless current sensing (e..g is this cable live), etc.
     
  6. Sensacell

    Well-Known Member

    Jun 19, 2012
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    I would not touch it- for any price.
    It would be fragile, awkward and annoying to use- when compared to the existing solutions. I cannot remember the last time I said "if only I had a multimeter..."
     
  7. RobeeJ

    New Member

    Mar 19, 2013
    24
    1
    Reminds me of the time I saw the Oscilloscope app for the iPhone (which obviously requires a cheap hardware addon):
    https://itunes.apple.com/gb/app/oscilloscope/id388636804?mt=8

    For a moment I thought, that's cool! But a short moment later I thought... there is no way in hell I'm connecting any external circuit with current in it to my £500 phone! Not when you can buy a better proper scope to risk destroying for less than that. :/

    Cool idea tho.
     
  8. wayneh

    Expert

    Sep 9, 2010
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    I think a series of sensor modules would be interesting, for instance a tire pressure device, a thermometer, a hall effect sensor for non-contact current, blood pressure cuff, pulse meter, volt/ohmmeter and on and on. (The pulse thing already exists). All of the sensors could rely on a smartphone for data logging, processing and display. Most could probably be bluetooth to eliminate any risks of direct contact and to increase convenience.
     
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