Issues with microSD card adapter

Discussion in 'General Electronics Chat' started by geekoftheweek, Oct 6, 2013.

  1. geekoftheweek

    Thread Starter Member

    Oct 6, 2013
    42
    2
    I am a bit stumped. I've been working on interfacing a microSD card to a pic. I went the route of soldering wires to the connections on the adapter that came with the card. I'm running the pic at 5 volts and the card at 3.3 volts. I'm using pull up resistors on the mosi, clock, and cs lines and bit banging the spi since I'm already using the mssp module for i2c. Everything shows up right on the logic analyzer without the adapter hooked up....

    The problem I'm running into is for some reason whenever I hook the adapter in for some reason the clock line gets pulled low. If I take it out of the breadboard and run the initialization process it works fine, but as soon as I plug the adapter in the clock gets pulled low. I tore apart another adapter that was doing the same thing to see if somehow there wasn't something inside that might be causing this, but don't see anything that would cause it. I've been fighting it for a while now to no avail.

    Anyone have any suggestions?
     
  2. geekoftheweek

    Thread Starter Member

    Oct 6, 2013
    42
    2
    After a bit of trial and error I did find there seems to be a short in the adapter between the clock pin and vss. As far as I could tell the one I tore apart was more or less a direct pin to pin adapter with no other components inside. Maybe there's a string of solder or something between the two I can't see or something... Just seems weird both adapters did the same thing.
     
  3. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,388
    1,605
    Do you have any sore of documentation on the connector you are reusing? I'd be surprised if you did, there seems to be thousands of different sockets out there.

    A pin that gets pulled low when the card is inserted sounds more like a card detect line then a clock line.
     
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