Re: [avr-chat] Another problem - this time with I2C

[John Altstadt]

Colin O'Flynn wrote:
> Hey,
>
> If the I2C device wasn't responding, would your program freeze up as you 
> describe? It could be that the I2C device is in reset still when the AVR is 
> trying to talk to it...
>
>  -Colin
>
> > However, with I2C, the program runs as soon as I download the program, but
> > if I turn off the 5v and turn it back on again, the program won't run at
> > all.

I just had what may be a similar problem. As far as I could tell, 
sometimes when the system started up, the slave I2C device thought it 
was in the middle of a transaction and it would hold the bus in an 
active state.

I solved it by:
- at startup, configure the I2C clock line as a regular output port
- toggle the clock line several times to flush the slave device
- configure the I2C port correctly

John