I have setup an [ATMega328P to interface with [this board. I know TWI is working because I have [EEPROM that is returning data. When I examine the TWI data via [logic analyzer, I can see the Start + Slave Addr (R/W=0), but the chip is replying with a NACK. Has anybody else gotten this to work? I’m using the [Example code from the [product page.
I know the chip won’t respond with an ACK after the reset command is sent, but I can’t even get the chip to send an ACK after I send TWI start + slave address + W. I’ve tried various TWI bus speeds of 400kHz, 100kHz and 40kHz, all with the same result. My logic analyzer is showing the time between clock transitions correctly, so I know the bus speed is being set correctly. I have pull-up resistors in place, and can read 128KB of data from the EEPROM, no problem.
I’ll update this post later with the logic analyzer session data.](http://www.sparkfun.com/products/10617)](http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Prototyping/lipo_fuelgauge-v10.zip)](http://www.sparkfun.com/products/8938)](http://www.mouser.com/ProductDetail/Atmel/AT24C1024B-PU25/?qs=sGAEpiMZZMuVhdAcoizlRWOm7B1K2DLjxQAyu2zlyuY%3D)](http://www.sparkfun.com/products/10617)](AVR 28 Pin 20MHz 32K 6A/D - ATMega328P - COM-09061 - SparkFun Electronics)