External EEPROM can't read/write


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  1. #10
    Join Date
    Oct 2005
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    Default Exactly, a no brainer

    It's the fact that this should be a "no brainer" that is so baffling. I've breadboarded much more complicated circuits, yet this simple EEPROM circuit won't work. I thought perhaps someone else had encountered this type of problem before and knew of a solution or could identify a source for troubleshooting.

    A digital probe pulses away on both SCL and SDA during read/write ops.

    BTW, I scoped portc.4 and c.3 outputs and SDA and SCL appear to be working. See Scope.jpg with data on top and clock on bottom. Both high prior to write/read operation and data high, clock low after write/read op. However, after a couple minutes, the clock goes high. I have no idea why.

    The write-data signal doesn't change thoughout the write process and it's the same for the read-data signal, but the read signal is not the same as the write signal. See Scope2.jpg.
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    Last edited by coyotegd; - 11th May 2008 at 22:50.

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