MPR121 Capacitive Touch Sensor ModuleSKU 2126

Sensors & Modules

MPR121 Capacitive Touch Sensor Module

₹140

01 — About

What it does

The MPR121 Capacitive Touch Sensor Module is a highly advanced, 12-channel capacitive touch sensor controller designed by NXP (Freescale). Featuring a simple I2C interface, it can turn almost any conductive material—including fruits, plants, or custom copper pads—into highly sensitive touch or proximity buttons. With built-in auto-configuration, auto-calibration, and advanced hardware filtering, it offloads the heavy processing from your main microcontroller. It is perfect for creating custom touch panels, interactive art installations, musical instruments, and modern human-machine interfaces.

Key features

  • 12 independent capacitive sensing inputs (channels)
  • Simple I2C interface for easy microcontroller communication
  • Built-in auto-configuration and auto-calibration
  • Advanced hardware filtering for noise rejection
  • Capable of both touch and proximity detection
  • Low power consumption with configurable sleep modes
  • Ideal for replacing mechanical buttons in consumer electronics

Good to know

  • The MPR121 is natively a 3.3V logic device. If using a 5V microcontroller, ensure your breakout board has a built-in voltage regulator and logic level shifter, or use an external level shifter.
  • Keep the wires connecting the sensor to the touch pads as short as possible to minimize electrical noise and false triggers.
  • Ensure your microcontroller code configures the charge/discharge current and filtering settings appropriately for the specific material you are sensing.
  • Proper grounding is essential for stable capacitive sensing; ensure the ground of your circuit is solidly connected.
  • Be aware of the default I2C address (0x5A) if you are chaining multiple sensors on the same bus.

02 — Datasheet

Specifications

10
Driver IC
MPR121 (NXP / Freescale)
Number of Channels
12
Operating Voltage
2.5V to 3.6V (5V tolerant on some breakout boards)
Communication Interface
I2C (up to 400 kHz)
Default I2C Address
0x5A (Configurable up to 0x5D)
Detection Types
Touch and Proximity
Response Time
Configurable (Fastest approx. 16ms)
Application Type
HMI, touch keypads, IoT, interactive art
Dimensions
Varies by model (approx. 25mm x 25mm)
Weight
Varies by model (approx. 3g)