MPR121 Breakout V12 Capacitive Proximity Sensor

Description

What it is

The MPR121 Breakout V12 is a capacitive proximity sensor that allows non-invasive detection of objects through an electric field. This breakout board is ideal for implementing capacitive interfaces in various Arduino projects.

Features

• MPR121 Sensor with 12 dedicated electrodes

What it is for

The MPR121 can be used to create capacitive interfaces, monitor user interaction non-invasively, or integrate into 3D printing and drone projects. It is compatible with Arduino and ESP.

Tutorial: How to use MPR121 Breakout V12

The MPR121 is a capacitive proximity sensor ideal for makers who want to create capacitive interfaces or monitor user interaction non-invasively. With 12 dedicated electrodes, it is perfect for both beginners and more experienced creators.

What you need

• Arduino Uno
• MPR121 Breakout V12
• USB power supply
• connection cables

Steps

1. Connect the MPR121 to the Arduino pins SDA and SCL using the cables.
2. Install the Adafruit_MPR121 library through the Arduino Library Manager in the IDE.
3. Upload the example sketch provided by the library to the Arduino.
4. Check that the sensor responds correctly to touches on its electrodes.
5. Modify the code to adapt it to your specific project.

Example code

// Includi la libreria
#include <Adafruit_MPR121.h>
// Crea un oggetto MPR121
Adafruit_MPR121 cap = Adafruit_MPR121();
void setup() {
cap.begin(0x5A); // Verifica l'indirizzo I2C sul datasheet
}
void loop() {
for (uint8_t i=1; i<=12; i++) {
if (cap.touched(i)) {
Serial.print("Elettrodo ");
Serial.println(i);
}
}
delay(50); // Verifica la frequenza di aggiornamento sul datasheet
}

Mini project

Create an LCD display that changes the message in response to touches on the different electrodes of the MPR121.

Common mistakes

• Do not verify the I2C address of the sensor
• Ignore the configuration of the interrupt pins
• Use an unsupported power supply voltage
• Enter incorrect code to handle touches

Recommended accessories

• LCD 16×2
• Pull-up resistors
• Breadboard
• Ambient light sensors

Frequently asked questions

How can I configure the sensor to only respond to certain electrodes?
Use the set_{electrode}_threshold() methods of the library to adjust the sensitivity.

The sensor does not respond to touches, what should I do?
Check the connections and ensure that the sensor is properly powered.