You'll need the following parts to build this project:
- MPR121 Breakout
- If you haven't assembled it yet, follow the MPR121 guide to solder the breakout board.
- Long wires, aluminum foil, or other surface to use as capacitive touch inputs to the MPR121.
- Raspberry Pi (any model A, B, A+, or B+), or BeagleBone Black.
- Breadboard and jumper wires.
Place the MPR121 board into a breadboard and connect its inputs to the electrodes you plan to use. Then follow the wiring below for your platform to connect the MPR121 to an I2C communication channel.
On a Raspberry Pi connect the hardware as follows.
Note: Make sure you've enabled I2C on your Raspberry Pi!
- Connect Raspberry Pi 3.3V to MPR121 VIN.
- Connect Raspberry Pi GND to MPR121 GND.
- Connect Raspberry Pi SCL to MPR121 SCL.
- Connect Raspberry Pi SDA to MPR121 SDA.
On a BeagleBone Black connect the hardware as follows. If you aren't familir with how pins are numbered on the BeagleBone Black be sure to read this guide first.
- Connect BeagleBone Black 3.3V pin P9_3 to MPR121 VIN.
- Connect BeagleBone Black DGND pin P9_1 to MPR121 GND.
- Connect BeagleBone Black I2C2 SCL pin P9_19 to MPR121 SCL.
- Connect BeagleBone Black I2C2 SDA pin P9_20 to MPR121 SDA.
Once the hardware is connected to your development board, continue on to learn how to install the software for this project.