AVR-Chat

> On 12/14/06, James Ronald <jronald@chartermi.net> wrote:
>> Tonight I tried to compile the i2c examples in AVRlib.  I found that the 
>> AVR
>> Butterfly does not support i2c the same as the ATmega8, 128, 16, 163 and
>> such.  Instead, the 169 uses the USI to do TWI.   I did find Atmel
>> application note 310 which describes how to go about setting up USI to do
>> TWI but I was hoping to find another example as well.  I have searched 
>> for
>> the past few hours with little luck.  I'm surprised that I could not find
>> examples of connecting an AVR Butterfly to a SRF08 an i2c compus or such.
>> Anyway, if anyone has a TWI USI example I would be appreciative.
>
> The openservo project: http://www.openservo.com/ was originally
> designed for the AVR Tiny45/85 and it uses USI
> http://www.openservo.com/viewcvs/viewcvs.cgi/OpenServo/ATtinyX5_Bootloader/
>
> -- 
> Dave Hylands

Thanks for the link Dave.  It looks like a good starting point.  I was 
hoping to just put USI into TWI mode and just map the USI to TWI register 
names and such.  It looks like it's going to be quite involved and is going 
to take some time to figure out.  Other than the openservo project it looks 
like projects needing TWI (i2c) just stayed away from the USI 
implementation.  I mean if professional developers are shying away from USI 
implementations of TWI should I as a hobbyist?  Am I just wasting my time?