08-11-2020 02:13 PM
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:
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:
Can anyone help me understand the datasheet?
08-12-2020 06:23 AM - edited 08-12-2020 06:24 AM
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.