AVR-Chat

Do you have external pullup resistors? Internal pull-ups are around 25K (IIRC) but desired value is under 1.5K.

Jim Wagner

On May 19, 2013, at 2:35 AM, Dave McLaughlin wrote:

> Hi all,
> 
> I have an ATMega328P and trying to use the I2C Master interface but when I
> send the start bit I am seeing a series of what appears to be clocks on the
> SCL line and nothing on the SDA.
> 
> I would expect SDA to be high at the same time as SCL goes hi and then SDA
> goes low but all I see is a clock output on SCL.
> 
> I am using the library from this website.
> 
> http://homepage.hispeed.ch/peterfleury/group__pfleury__ic2master.html
> 
> Any ideas what I am missing?
> 
> Dave.
> 
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> 
> 



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