AnsweredAssumed Answered

About BIT BANG for AD5254

Question asked by noah4ever on Oct 25, 2012
Latest reply on Oct 30, 2012 by musach

Hi, guys,

 

I need your help with I2C bit bang for AD5254 as my MCU doesn't support I2C.

I was trying to talk to AD5254 with its quick command write mode, but the digipot was not responding. I also tried to measure the resistance of RDACs, but it's either "Open Loop" or "0". The voltage across the wiper and terminal A was around 3.5V, and 0.04V between wiper and terminal B. I know the numbers are incorrect, but I really don't know how to fix it. The supply voltage of my circuit was DC +5V and 0 for GND from external voltage source, I have measured it and it's stable.

I attached the datasheet of AD5254, my code and my schematic diagram here. Pls have a look and tell me what went wrong.

PS, I tested my MCU with LEDs and some loops, it was working, so I don't think it's MCU's hardware problem.

 

Many Thanks!!!

 

CH

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