Controlling AD5141 Digital Potentiometer using I2C in LabVIEW 2014

[bdnguyen]

Hi,

I am having a hard time trying to communicate to the device and setting the wiper. I have attached the code and the data sheet for the part. Any help would be appreciated. ADDR0 and AAR1 pins are No Connect.

[wiebe@CARYA]

What is not working?

Do you get anything? Any sign of life? Data? Errors? Blue screens? Smoke?

First step is to somehow validate the physical layer.

Next, establish any communication (even if it's with 3rd party software).

Then, work out the details. 

[bdnguyen]

I am getting error 301742 when running the attached VI. I have 1K pull-up resistors on the I2C data and clock line right at the 8451 connector. The device address is 2A according to the device's spec (ADDR0 and ADDR1 pins are No Connect.)

I was successful setting the Digi Pot to a desired wiper position ONLY when it was on an eval board. So I know the code is OK in that scenario.

But when I tried the same code on the product PCB then I got the error. The difference is the I2C data and clock lines also have 3.92K pull-up resistors on the PCB and those two line are also tied to a microcontroller. I am wondering if the microcontroller is interfering and not letting the 8451 seize the bus.