Description
The MPR121 chip can handle up to 12 individual touch pads. The MPR121 has support for only I2C, which can be implemented with nearly any microcontroller. You can select one of 4 addresses with the ADDR pin, for a total of 48 capacitive touch pads on one I2C 2-wire bus. Using this chip is a lot easier than doing the capacitive sensing with analog inputs: it handles all the filtering for you and can be configured for more/less sensitivity.
Key Features:
- 12-channel capacitive touch sensor breakout board, starring the MPR121
- Can handle up to 12 individual touch pads
- MPR121 has support for only I2C
- A 3V regulator and I2C level shifting
- An LED onto the IRQ line so it will blink when touches are detected
- Dimensions: 33mm x 19mm x 2mm / 1.3" x .8" x .1"
- Weight: 2.2g
- Uses I2C 7-bit address 0x5A (can be set to 0x5B, 0x5C or 0x5D)
Relevant Resources:
Datasheets, PCB files and Fritzing object available in tutorial
