The UXP expansion port found on ProXR series controllers (equipped with a UXP port) support the ability to control digital potentiometers.  Use the digital pot expansion boards for tuning of external analog circuits, audio control applications, or scientific control and simulation applications.  Digital potentiometers offer 8-bit resolution with the ability to control many channels individually or simultaneously.  Digital potentiometer outputs are available in 10K, 50K, and 100K ohm resistance.  Digital potentiometers are limited to working with analog circuits in the 0 to 5V range, and are current limited to 1ma per channel.  Exceeding the voltage or current on any of the potentiometers may result in permanent damage.

The following commands demonstrate how to control digital potentiometers from ProXR controllers equipped with UXP hardware and firmware using the Channel (C) and Value (V) parameters.  The channel value is used to identify which potentiometer you would like to control.  The value parameter controls the wiper of the potentiometer.  A value of 0 set the wiper all the way to the left.  A value of 128 moves the wiper to the center position.  A value of 255 move the wiper all the way to the right.  Note, as with most potentiometers, there are 3 contact points per potentiometer.

CK = Checksum (00-FF)
C = Channel
V = Value
AA04FEAA004096Set Potentiometer Output 0 to 64 (25%)AA015500
AA04FEAA0080D6Set Potentiometer Output 0 to 128 (50%)AA015500
AA04FEAA00FF55Set Potentiometer Output 0 to 255 (100%)AA015500
AA04FEAA014097Set Potentiometer Output 1 to 64 (25%)AA015500
AA04FEAA0280D8Set Potentiometer Output 2 to 128 (50%)AA015500
AA04FEAA03FF58Set Potentiometer Output 3 to 255 (100%)AA015500

Users may want to set all potentiometer outputs simultaneously:

CK = Checksum (00-FF)
V = Value
AA03FEAB4096Set All Potentiometer Outputs to 64 (25%)AA015500
AA03FEAB80D6Set All Potentiometer Outputs to 128 (50%)AA015500
AA03FEABFF55Set All Potentiometer Outputs to 255 (100%)AA015500

Leave a Reply