The MPR121 12-Channel Capacitive Touch Sensor Controller Module is based on NXP’s MPR121QR2 and communicates via an I2C interface. It supports up to 12 individual capacitive touch inputs and includes a simulated 13th electrode. Additionally, it features 8 pins that can be used for LED control when not configured as electrodes.

This breakout board includes four default-closed jumpers. One sets the I2C address (default: 0x5A) by tying the ADD pin to ground. To change the address, open this jumper before reconfiguring. The other jumpers connect SDA, SCL, and the interrupt pin to 10k pull-up resistors, which can be disabled by cutting the trace.

Note: The board has no onboard voltage regulation. It must be supplied with 2.5–3.6VDC. The VREG pin is connected via a 0.1μF capacitor to ground, so the module cannot operate in low-voltage mode (1.71–2.75VDC) without hardware modifications.