CapacitiveTouch Library

The CapacitiveTouch Library is designed to simplify the use of capacitive touch sensors on Arduino UNO-R4 boards (Minima and WiFi). This library hides the low-level hardware details (CTSU, DTC, interrupts, etc.) and provides a simple, user-friendly API for beginners and educational projects.

Features

• Easy to Use API:
  Initialize your sensor with just one constructor call and use simple methods to read sensor values and detect touches.
• Board Support:
  Compatible with Arduino UNO-R4 Minima and UNO-R4 WiFi boards.
• Low-Level Abstraction:
  All complex tasks (hardware setup, measurement control, interrupt management) are abstracted away so you can focus on your project.

Installation

1. Copy CapacitiveTouch.h and CapacitiveTouch.cpp into your Arduino libraries folder.
2. Restart your Arduino IDE so it recognizes the new library.

Compatible Pins

Arduino UNO-R4 Minima

Arduino Pin	Touch Sensor Channel (TS#)	Channel Control Index (CHAC idx)	Channel Control Bit Mask (CHAC val)
D0	9	1	(1 << 1)
D1	8	1	(1 << 0)
D2	34	4	(1 << 2)
D3	13	1	(1 << 5)
D8	11	1	(1 << 3)
D9	2	0	(1 << 2)
D11	10	1	(1 << 2)
D13	12	1	(1 << 4)
A1 (D15)	21	2	(1 << 5)
A2 (D16)	22	2	(1 << 6)
LOVE_BUTTON	0	0	(1 << 0)

Arduino UNO-R4 WiFi

Arduino Pin	Touch Sensor Channel (TS#)	Channel Control Index (CHAC idx)	Channel Control Bit Mask (CHAC val)
D0	9	1	(1 << 1)
D1	8	1	(1 << 0)
D2	13	1	(1 << 5)
D3	34	4	(1 << 2)
D6	12	1	(1 << 4)
D8	11	1	(1 << 3)
D9	2	0	(1 << 2)
D11	7	0	(1 << 7)
D12	6	0	(1 << 6)
A1 (D15)	21	2	(1 << 5)
A2 (D16)	22	2	(1 << 6)
LOVE_BUTTON	27	3	(1 << 3)

Note: Only the above pins are supported. Other pins are not configured for capacitive touch sensing.

Usage Example

#include "CapacitiveTouch.h"

// Instantiate a capacitive touch sensor using the LOVE_BUTTON macro.
CapacitiveTouch ct = CapacitiveTouch(LOVE_BUTTON);

void setup() {
  Serial.begin(9600);
  ct.begin();
  ct.setThreshold(500); // Adjust threshold (lower values increase sensitivity)
  Serial.println("CapacitiveTouch Library: LOVE Button test");
}

void loop() {
  int sensorValue = ct.read();
  Serial.print("Raw Value: ");
  Serial.println(sensorValue);
  
  if (ct.isTouched()) {
    Serial.println("LOVE button touched!");
  }
  delay(100);
}