MPR121 12-Key Capacitive Touch Sensor Module (I2C)

Details

Breakout board for the MPR121 capacitive touch controller. It gives you 12 touch inputs over I2C, so you can build touch buttons or keypads from copper pads, conductive tape or foil. The chip handles touch filtering and calibration itself. It also has an IRQ output that tells your MCU when a touch changes, and 8 of the 12 electrode pins can drive LEDs or work as GPIO. This is a 3.3 V board. The MPR121 chip is rated up to 3.6 V and this board has no regulator or level shifter marked, so do not connect VCC or the I2C lines directly to 5 V. The photo is a reference image, and the chip specifications and datasheet are for the MPR121 itself.

Specifications

• Controller: MPR121
• Touch inputs: 12 electrodes
• LED/GPIO: 8 of the 12 pins
• Interface: I2C with IRQ output
• I2C address: 0x5A to 0x5D, set by the ADDR pin
• Supply: 3.3 V (chip absolute maximum 3.6 V)
• Operating temperature: -40 to +85 °C (chip)