Hmm... So I've found that devices are "hardcoded" to be at certain addresses.  So now I'm stumped as to why I'm getting timeouts on my I2C bus for transactions with my robostix.  Anyone ever used this "Spyglass" lcd backboard? 

http://hubbard.engr.scu.edu/embedded/spyglass/

This page tells me the addresses I need, as well.  So I must have a wiring issue at this point and its causing real issues on my bus.  Is there a impedance issue with the I2C bus?  I recall reading something about pullups being needed for the bus as a whole and not per device... 




On 7/20/06, Ed Camacho <ecamacho@gmail.com> wrote:

I picked up an LCD mounted on an I2C enabled backboard.  I'd like to interface it with my Gumstix + Robostix combo.  I've hooked up ATM_SCL and ATM_SDA as well as power and ground to it.  I have a couple of questions:

1)  How do I find out the address of this device?  When I modprobed i2c-pxa, I was expecingt to see a list of all devices.  Instead, I get nothing (I2C is working, as i2c-io works fine).
2)  When I hook up the LCD, I can't seem to talk to my robostix anymore.  Do devices change address?  Why is the robostix referred to as device 0x0b in the first place?  How is this all configured?

Thanks!
Ed