Datasheet

I2C Pins

SCL - I2C clock pin, connect to your microcontrollers I2C clock line.

SDA - I2C data pin, connect to your microcontrollers I2C data line.

IRQ and ADDR Pins

ADDR is the I2C address select pin. By default this is pulled down to ground with a

100K resistor, for an I2C address of 0x5A. You can also connect it to the 3Vo pin for an

address of 0x5B, the SDA pin for 0x5C or SCL for address 0x5D

IRQ is the Interrupt Request signal pin. It is pulled up to 3.3V on the breakout and when

the sensor chip detects a change in the touch sense switches, the pin goes to 0V until

the data is read over i2c

https://learn.adafruit.com/adafruit-mpr121-12-key-capacitive-touch-

sensor-breakout-tutorial

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