arduino_dualtouch

A simple capacitive touch sensing class for arduino, using two sensors

Usage

Connect two touch sensors to any analog I/O pins of Arduino. I used two pieces of copper foil, about 1 x 2 cm, spaced 1 cm of each other. Insulate the sensors so that user can not directly touch the sensors (e.g. using a plastic sheet). No resistors or anything is needed.

Code example is below. Depending on the sensor sizes etc. you may need to tune the sensitivity (with setThreshold(float)) or the filtering gains (with setFilterGains(float, float)).

The sensors are connected according to this figure. Left side shows the microcontroller internals (Atmega32U4 in my case). The capacitance between the sensors is the parasitic capacitance (not a discrete component).

The sensors could be connected to e.g. A0 and A1 pins (18 and 19 in code below).

Code example

This simple code (which I did not test ;) initializes the two sensors and then prints the press status over serial.

#include "DualTouch.h"

DualTouch touchSensors(18, 19);   // Sensors in pins 18 and 19 (Arduino pro micro A0 and A1)

void setup() {
  Serial.being(9600);
}

void loop() {
  touchSensors.update();
  Serial.print(touchSensors.leftTouched());
  Serial.print('\t');
  Serial.println(touchSensors.rightTouched());
  delay(100);
}