17 responses

  1. cnxsoft
    December 28, 2013
  2. cnxsoft
    December 28, 2013
  3. onebir
    December 28, 2013

    “I’ve connected it between my hub and my camera, and I had no problem browsing the files. However, I would only get proper voltage readings, with current always showing as 0.00A, even when importing videos to my computer.”
    So no way to work out power consumption in this case?

    Reply

  4. cnxsoft
    December 28, 2013

    @onebir
    Power (P) = Voltage (U) x Current (I). If the current is zero, then power is zero.
    One reason could be that my camera current was less than 0.01 during the test (So less than 50 mW), or at least less than could be measured accurately with the device. For low power consumption and/or better accuracy, using a multimeter is preferable, but I still think in many cases, this cheap and small meter can be useful.

    Reply

  5. onebir
    December 28, 2013

    @cnxsoft
    Oh ok; I thought the 0.00A reading might not be plausible…

    Reply

  6. Marius
    December 29, 2013

    I have this one. Bought it from ebay for $3 including shipping. I must say though that build quality seems really bad, the soldering is bad that is.
    Also I’m having strange problems with some devices not charging properly when connected through.
    When it works though it is kinda cool and it seem pretty accurate.

    Reply

  7. zoobab
    December 29, 2013

    Any way to hook some arduino to sniff the values of the screen in order to do some real data logging?

    Reply

  8. mcg
    December 29, 2013
  9. Marius
    December 29, 2013

    @zoobab
    Most of the soldering pads on it are quite large so it shouldn’t be much of a problem to hook something up. The real problem is just where I think.

    Reply

  10. Softspot
    January 15, 2014

    @onebir No current displayed? Simple: the camera is propably powered by it’s own battery so no power is taken from the USB-port, it is only used for data-transmission. And when no power is used no current can be measured.

    Reply

  11. cnxsoft
    January 15, 2014

    @Softspot
    I should have thought about it, as the camera battery will just discharge if I leave it connected to my PC.
    Data transmission should also consume some power, but I guess the device only measures current from the VCC pin, and not the D+/D- pins of the USB connector… I think I got it!

    Reply

  12. Softspot
    January 16, 2014

    @cnxsoft If you take a look at http://forum.xda-developers.com/showthread.php?t=2451375 and scroll down a fair bit, you’ll reach some pictures of this nifty little thing opened up. The 2nd pic shows that you guessed correct: it only meaures the power-lines of the USB lead, not the datalines. (the outer connections are diverted to the convertor, and those are the +5V and ground. The two inner connections are directly connected from in to outplug, and those transport the data.)

    Reply

  13. zoobab
    September 30, 2015

    Bought one today from Action shop in Brussels for 2.5EUR VAT incl. The 2×8 pins chip is EM78P259NS016J. It is an 8bits chip: http://www.emc.com.tw/Eng/database/Data_Sheet/8BIT/EM78P259N.pdf

    Reply

  14. zoobab
    September 30, 2015

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