SparkFun Touch PotentiometerSparkfun
The SparkFun Touch Potentiometer, or Touch Pot for short, 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 such as volume control and LED dimming.
The Touch Potentiometer is controlled by a Microchip PIC16F1829 8-bit micro-controller that provides the host interface, LED control, capacitive sense and peripheral control functions. A built-in low-dropout voltage regulator allows operation over a range of input voltages up to 12V and breadboard friendly connectors make it easy to play with. A desktop application has been created by our collaborator, Dan Julio, that communicates with the Touch Pot over a serial connection. From this utility app you can change configuration settings, alter LED behavior, calibrate the capacitive touch sensor, view current readings in jabber mode, and much more.
Note: This product is a collaboration with danjuliodesigns. A portion of each sales goes back to them for product support and continued development.
- 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
- Built-in 5V LDO voltage regulator
- Through-hole and SMT connectors