CY3218-CAPEXP1: 4 Button Cap Sense

The CY3218-CAPEXP1 CapSense® Express™ Evaluation Kit is used to evaluate the CapSense Express device. This kit demonstrates the following features: CapSense buttons, LED drive, digital input, and I2C. The CapSense Express device is configured via a system-level project in PSoC® Designer™. A 16-pin QFN CY8C20110 device is mounted on the board. The board is powered with a AAA battery. A boost converter converts the input, in the range of 1.1 V to 1.5 V, to the device operating voltage of 3.3 V. The board can also be powered using the CY3240-I2USB bridge, connected to the I2C header.

These CapSense Express™ controllers support four to ten capacitive sensing (CapSense) buttons. The device functionality is configured through an I2C port and can be stored in onboard nonvolatile memory for automatic loading at power-on. The CY8C20110 is optimized for dimming LEDs in 15 selectable duty cycles for back light applications. The device can be configured to have up to 10 GPIOs connected to the PWM output. The PWM duty cycle is programmable for variable LED intensities.

The four key blocks that make up these devices are: a robust capacitive sensing core with high immunity against radiated and conductive noise, control registers with nonvolatile storage, configurable outputs, and I2C communications. The user can configure registers with parameters needed to adjust the operation and sensitivity of the CapSense buttons and outputs and permanently store the settings. The standard I2C serial communication interface enables the host to configure the device and read sensor information in real time. The I2C address is fully configurable without any external hardware strapping.

(Infineon Technologies bought Cypress Semi)