Level Sensor

Discussion in 'Electronics Resources' started by jpanhalt, Mar 30, 2011.

  1. jpanhalt

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    Jan 18, 2008
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    I am learning to operate a tractor. One problem is that the bucket/forks do not maintain a constant angle with reference to the ground (i.e., level) as the front-end loader is raised. That is not such a problem with a bucket, but it can be embarrassing with pallet forks.

    Does anyone know where to get the actual sensor for an electronic level? I could try hacking an "electronic level," but would prefer to buy just the sensor and have a datasheet to work with.

    My idea is to build a device that would attach to the bucket or pallet forks and show the position relative to Earth level on, say, 5 LED's. Center would be level, one LED up or down from that would be + or - 3° and the top or bottom LED would show more than that angle.

    A simple level won't work, because my reading position is on the wrong axis.

    John
     
  2. StayatHomeElectronics

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    Sep 25, 2008
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    I think that this part could definitely do the job... Not sure if it would be easier than just hacking the "electronic level." :)

    http://www.analog.com/static/imported-files/Data_Sheets/ADIS16203.pdf

    If you search around for other "inclinometers" you may find something to suit your needs.

    EDIT: Forgot to say it is available from DigiKey as a demo board.
     
  3. jpanhalt

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    Thanks for the nudge.

    It was a momentary brain lapse. I was looking under level sensors, and of course all of the hits were for liquid level detection. I had thought of using a gryo sensor for a model, which would give a pwm output. There appear to be other affordable ($20 or so) inclinometers that give an analog output that would be easy to display on something like an LED bar (e.g., Memsic CXTA series).

    In other words, the proper search term, "inclinometer" had skipped my mind. As you suggest, maybe the simplest approach would still be to hack a level and turn the display 90° to the sensor so it can be read from the tractor seat.

    John
     
  4. soundman

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    Dec 27, 2010
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  5. jpanhalt

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    I considered and discarded the idea of a leveling laser, because it projects a line that is level to the sensor. That line would just go up and down with the loader. It would always be level, but it would not indicate whether pallet forks attached to the loader were level.

    Thanks for the idea, though.

    John
     
  6. jpanhalt

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    I just bought the Craftsman Digital Torpedo level (#48995) for $21.24 -- It is currently on sale and discounted an additional 15% for Internet orders today.

    We'll see if the case can be opened tonight.

    John
     
  7. StayatHomeElectronics

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    Sep 25, 2008
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    Just took a peek at the Craftsman Digital Torpedo level. This is probably one of the only times where a review of "not as solid as others" is actually going to be a benefit. From the pictures, I think you have a very good chance of getting it open.
     
  8. jpanhalt

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    @StayatHomeElectronics

    You are absolutely right. It comes apart with a few screws. The senosr board is separate and has the Memsic MXD2020E dual axis sensor with a sensitivity of ±1 g. Operates on 3 to 5 V or so. It puts out a simple PWM signal. The board has a chip on it, F301. Communication to the display is 4-conductor cable. The display is a COB, green phosphor screen. You also get a temperature readout. Not bad for about $22.

    DigiKey has the MSD2125 on a dip adapter board for $31.91. That unit is ±2 g.

    Based on those numbers, I'd say we should list Sears as a low-cost component supplier for a limited number of specialized chips and evaluation boards. ;)

    John
     
  9. StayatHomeElectronics

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    Sep 25, 2008
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    We certainly couldn't beat that price for the chip, a board, a display, and packaging. Good find.

    Also, sounds like you have plenty of options to make it work for you project. You could use the display and/or add leds.

    Good luck mounting it to your tractor!
     
  10. jpanhalt

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    The sensor and MCU(?) just send serial tilt data on one channel, one channel may be a null or a ready (0100), and the other two wires are power. I may just try a twisted cable first. If needed, a dual op amp for the signal lines. Since it is so modular, I will probably keep the control unit with its bells and whistles (literally, it can be set to buzz at level or any user-defined zero point) and mount it with Velcro to my dashboard when I am using the pallet forks.

    Got to get ready for Spring. I got about three inches of snow yesterday at the "farm" (West of Wellington on SR 18), but it is melting fast.

    John
     
  11. StayatHomeElectronics

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    Sep 25, 2008
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    Hopefully there is not much noise to be coupled into the lines along the way. I don't know much about automotive electronics and certainly nothing about adding electronics to tractors. :) Static might be your other concern.

    I guess there are plenty of ways of getting around it if it does happen.

    We got about an inch and a half of snow down the road in Akron. It's just about gone now.
     
  12. KMoffett

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    Dec 19, 2007
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    How about a pot with a offset weight on the shaft, an LM3914 bar/dot voltmeter IC, and a 10-LED bar display. Ok, maybe add an opamp for +/- 3° resolution.

    Ken
     
    Last edited: Apr 10, 2011
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