This GPS Logger Is So Small…


How small is it? Two things should give you a good sense of scale, the SD card slot on the lower right, and the slide switch on the upper left. This minuscule module is an all-in-one GPS logger which [J3tstream] built.

Main system control is provided by a Teens 2.0 board. If you look really closely you’ll see the SD card slot is actually a breakout board which mounts on top of the Teensy’s pinheaders. Also on the board is a PA6B GPS module with a few passive components to support it. The back side of the board hosts a Lithium Ion battery from an old phone. Note the mangled pin header which works as connectors for the battery. [J3tstream] even built a charger into the project. He’s using an LTC4054 chip to handle the charging. We were a bit confused at first because we didn’t see a way to connect external power. But he goes on to explain that the USB port on the Teensy board is used for charging. Just plug in USB and press the button to get things started.

50 thoughts on “This GPS Logger Is So Small…

  1. I wonder why he chose the LTC4054 over the much much cheaper (and more capable) MCP73811. The 73811 even includes a charge enable pin that could be driven directly by the teensy instead of the mosfet he’s using. The only thing one loses in the 73811 is the charge indication pin.

          1. I see what’s going on here. He probably didn’t have a battery, but had an old blackberry he wasn’t using anymore. So he took out the LCD screen and connected it to the battery terminals to make it look like there’s a battery there. The logger, along with the LCD screen, must be powered by the confusion of those looking at it.

      1. I have done it too. Hardest part is alignment. I did it by drilling a couple of registration holes, and then putting pins in them to keep the transfer from moving while ironing.

        Second hardest thing is making sure both sides etch at the same rate. Definitely need to flip and agitate the board during the etch.

        Third hardest is making sure the through holes are vertical. Use a drill press to bore holes. Angled holes will miss the pad on the backside.

    1. Don’t worry, the article states “SD card”, so it fooled me to belive it is a full size one. Once I took a look at pictures it was clear that that is a microSD, which makes the size much better. Not commenting as the poster of the first comment but as the followup :)

  2. It’s decently small, but I can think of ways to make it smaller. I’m not sure, but I think that GPS might have built in logging functionality. A serial command can be sent to it and it will log time/coordinates for several hours (internal flash). Couple it with one of those tiny LiPo cells from sparkfun and you could have a rudimentary microtracker that would have a few hour range. Nice build though, I really like the charging circuit, and the PCB looks super cool.

    1. Wow! You’re so smart. Except, if you read the datasheet (I did) you’ll find that this module does not have built in logging functionality. It needs external flash and a custom firmware option from the manufacturer. I am sure that the wonderful design *in your head* is *much better* than the thing *this guy actually built*.

      And HaD editors- for goodness sake read the comments and edit the story!! It’s a micro-SD card!

    1. If you need a very accurage GPS module, check out the ublox NEO-6p. Generally accuracy is <1m, and if the unit is stationary, the position can get down to centimeter accuracy. It also puts out raw GPS data if you want to do any post-processing. About $180ish from ublox's sample shop though, so a bit pricy.

  3. What is the accuracy of this unit, and do you think it would be easy to add a compass to it also? i’m thinking it would be a fun diy geotagger for my camera. his site lists a 17 hour life logging every 10 seconds. To power it i could probably tap into my camera’s battery grip as well. perhaps even make it write the location every time i snap a photo.

  4. Nice work. Pity the comments are all skewed by the title foolishly focussing no size. If it was all about size, it’d be pictured alongside a ruler, or simply state that its 85x40x10mm or whatever.

  5. Note the maker’s ‘feature’ list:

    – Better autonomy.
    – Be lightweight and portable.
    – Be rechargeable easily.
    – Got log directly from USB.
    – Upgrade code via IDE Arduino through USB.
    – Future options implemented for improvement.
    – Many more …

    Doesn’t say anything about size. It’s based on a teensy, it doesn’t claim to be teeny

  6. Thx everybody for your comments, basically, my goals was not the size, but the autonomies, and got the data quickly via USB.
    In hiking, I dont like to take my smartphone for gps because is heavy, bigger, and power consumption is hight! this project is only a logger, not a gps, my first prototype give me around 17hours of logging (with usb function disable).
    Mostly of gpslogger with pic or arduino find on google has not usb.
    The final cost is not so high, mostly components are sample, excepted gps, teensy and switch.
    Also you can use another kind of batterie, like a small Nokia BL-4D.

  7. @anybody that wants to compare to whats available on ebay ect

    nobody (here) cares what you could buy!
    this is NOT ebay groupon or dealoftheday!
    in fact the maker of this “mini” GPS
    probably ALREADY OWNS A BETTER/smaller ONE!

    if you want to compare to what one COULD buy,
    then stop posting here on this site.
    because this is a website dedicated to homemade
    andor modified contraptions.

    go back to where ANYBODY
    can find ANYTHING better then someone else’s search.
    we arent interested in buying a GPS logger.
    people here either already own a better/smaller one,
    or dont have the desire to own one.


    PS: what this guy did is he made the smallest
    HOMEMADE / DIY gps logger that made it to H.A.D. …

    MADE one better? post it! otherwise this IS
    the smallest HOMEMADE unit to make H.A.D.

    now all you ebay-trolls can
    whine and complain all you like.
    you will not make a dime off of ruinning/spamming
    this website

    signed, the defender of electronics-as-a-hobby

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