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Discussions on the software and hardware for Atmel's STK standard.
By dachew
#131717
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.
Last edited by dachew on Fri Aug 12, 2011 8:33 pm, edited 1 time in total.
By dachew
#131739
Well, it seems that maybe this was all for nothing. I re-wired the SCL/SDA pins to the Max17043 board, and it appears to be ACK'ing back now. I'm getting some weird results, but mostly it seems to be working. For example, the SOC was reporting about 2%, then 1%, now 0%, but my board is still trucking right along. I have a 850mA LiPo driving a boost circuit which is powering the rest of the board. The LiPo + line is powering the Max17043 just fine while running at a reported 0% charge. I'll admit that I know the battery is low...

Further experimentation!
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