Datasheet

Wiring
You can easily wire this breakout to any microcontroller, we'll be using an Arduino. For another kind of microcontroller,
just make sure it has I2C, then port the code - its pretty simple stuff!
Connect Vin to the power supply, 3-5V is fine. Use the same voltage that the microcontroller logic is based off of.
For most Arduinos, that is 5V
Connect GND to common power/data ground
Connect the SCL pin to the I2C clock SCL pin on your Arduino. On an UNO & '328 based Arduino, this is also
known as A5, on a Mega it is also known as digital 21 and on a Leonardo/Micro, digital 3
Connect the SDA pin to the I2C data SDA pin on your Arduino. On an UNO & '328 based Arduino, this is also
known as A4, on a Mega it is also known as digital 20 and on a Leonardo/Micro, digital 2
The MPR121 ADDR pin is pulled to ground and has a default I2C address of 0x5A
You can adjust the I2C address by connecting ADDR to other pins:
ADDR not connected: 0x5A
ADDR tied to 3V: 0x5B
ADDR tied to SDA: 0x5C
ADDR tied to SCL: 0x5D
We suggest sticking with the default for the test demo, you can always change it later.
Download Adafruit_MPR121
To begin reading sensor data, you will need to download Adafruit_MPR121_Library from our github repository. You can
do that by visiting the github repo and manually downloading or, easier, just click this button to download the zip
Download Adafruit_MPR121
© Adafruit Industries
https://learn.adafruit.com/adafruit-mpr121-12-key-capacitive-touch-sensor-breakout-
tutorial
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