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I2C Commanding of MCP4661T

I'm mostly an RF guy so understanding and reading digital datasheets kind of get to me. I need some help understanding the command protocol for this Potentiometer (MCP4661T). I cant program different resistances.

 

My Schematic is the following:

Capture.PNG 

My Device address is 0101001 so the 7-bit address is 0x29. Then in order to control/change the P0W I have been setting the internal address to 0x00 to command POT 0 registers, then I am sending any hex value from 0x00 to 0x100 for resistances.

 

My LabVIEW code is as followed:

Capture1.PNG

Can anyone help me understand the datasheet?

 

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1. Your 10k pull-up and pull-down resistors on the address lines should be 0 Ohm.  The device has built-in pull-up resistors, so you are causing a voltage divider and likely putting your device into an unknown address.

 

2. You should enable the internal pull-up on your I2C controller.

 

3. Unfortunately, you need to do some bit manipulations to build up a proper command here.  The is due to the Command Byte (the first byte of your command) has the register address, the command, and 2 bits of data in it.


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