Analog voltage controls digital potentiometer

摘要

This Design Idea describes an analog voltage that controls a digital potentiometer through the device's I~2C interface. An ADC in the Microchip PIC12F683 microcontroller converts the analog voltage to the PC stream that controls the Maxim DS1803 digital potentiometer (Reference 1). Of the microcontroller's six general-purpose I/O pins, two con-trol the SDA (system-data) and SCL (system-clock-line) output signals, one controls an LED, and one accepts the analog input. SDA and SCL connect directly to the digital potentiometer's SDA and SCL pins with 4.7-kfi pull-up resistors to V_(DD). By adding or removing jumpers, you can separate the shared V_c and V_(DD) and isolate SDA and SCL.