Original Touch Potentiometer

Available at tindie (and now in a digital-only version). The digital-only version does not include the AD5262 chip and has white LEDs.

This is the original design for the Touch Potentiometer and formed the basis for the Sparkfun collaboration . It is functionally identical to the Sparkfun version other than the color of the LEDs and requires a 5V power supply (does not have a built-in regulator). It works with the same demo sketches and tputil program.
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The Touch Potentiometer is an intelligent linear capacitive touch sensor that implements potentiometer functionality with 256 positions. It can operate as a peripheral to a computer or embedded micro-controller or in a stand-alone capacity. The Touch Potentiometer provides both a dual-channel analog and PWM output for direct control of other circuitry. Configurable analog and PWM transfer functions support a wide variety of applications.

Features


  • Dual host interfaces: Logic-level serial and I2CTM
  • Dual 8-bit 20 k-ohm 3-terminal digitally controlled variable resistor outputs
  • PWM output
  • 8 LED display with multiple display modes and intensity levels
  • Option for interpolated (soft) changes between touches
  • Configurable touch sensor parameters for a variety of PCB covers
  • Easily configurable I2C address to allow multiple devices on one bus
  • Configurable linear or non-linear PWM transfer function
  • Configurable linear or simulated logarithmic variable resistor transfer function
  • Variable resistor supports single- or dual-supply operation
  • Simple register interface with jabber option
  • Programmable power-on default operation
  • Built-in calibration procedure
  • User-accessible EEPROM data storage

Applications


  • Analog potentiometer replacement
  • Stereo channel audio level control
  • Computer peripheral
  • Embedded system control
  • Dimmer for LED lighting applications
  • DAC replacement

Downloads


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tputil program

User and programming manual.