Paste the code below into the Adafruit Arduino IDE or select download to pull the code from GitHub. For more information about programming Flora and to download the IDE, please visit the Getting Started with FLORA guide.

You'll also need Modern Device's capacitive touch sensing library for Arduino. Refer to the Adafruit Guide All About Arduino Libraries for help installing libraries.

// SPDX-FileCopyrightText: 2019 Limor Fried for Adafruit Industries
// SPDX-FileCopyrightText: 2019 Becky Stern for Adafruit Industries
// SPDX-License-Identifier: MIT

Example code for a Flora game controller with capacitive touch sensing! Full tutorial and video:
Uses Modern Device's Capacitive Sensing library:
  Adafruit invests time and resources providing this open source code, 
  please support Adafruit and open-source hardware by purchasing 
  products from Adafruit!
  Written by Limor Fried & Becky Stern for Adafruit Industries.  
  BSD license, all text above must be included in any redistribution
#include <CapPin.h>
#include <Keyboard.h>

CapPin cPin_10 = CapPin(10);    // read pin 10 (D10 on Flora) - connect to NES B
CapPin cPin_9  = CapPin(9);     // read pin 9 (D9 on Flora)   - connect to NES A
CapPin cPin_6  = CapPin(6);     // read pin 6 (D6 on Flora)   - connect to NES Start
CapPin cPin_12 = CapPin(12);    // read pin 12 (D12 on Flora) - connect to NES Select
CapPin cPin_1  = CapPin(1);     // read pin 1 (TX on Flora)   - connect to NES right
CapPin cPin_0  = CapPin(0);     // read pin 0 (RX on Flora)   - connect to NES up
CapPin cPin_2  = CapPin(2);     // read pin 2 (SDA on Flora)  - connect to NES left
CapPin cPin_3  = CapPin(3);     // read pin 3 (SCL on Flora)  - connect to NES down

CapPin pins[] = {cPin_10, cPin_9, cPin_6, cPin_12, cPin_1, cPin_0, cPin_2, cPin_3};
// check for more info on unique keys

// WASD D-pad, select = Return, start = Space, LeftButton = z, RightButton = x
//char Keys[] =   {  'x',    'z',    ' ',     KEY_RETURN,    'd',     'w',    'a',    's'};

// arrow D-pad, select = Return, start = Space, LeftButton = b, RightButton = a
char Keys[] =   {  'a',    'b',    ' ',     KEY_RETURN, KEY_RIGHT_ARROW, KEY_UP_ARROW, KEY_LEFT_ARROW, KEY_DOWN_ARROW};

boolean currentPressed[] = {false, false, false, false, false, false, false, false};

// Capactive touch threashhold, you might want to mess with this if you find its too
// sensitive or not sensitive enough
#define THRESH 500

float smoothed[8] = {0,0,0,0,0,0,0,0};

void setup()
  //while (!Serial)

void loop()                    
  for (int i=0;i<8;i++) {
    long total1 = 0;
    long start = millis();
    long total =  pins[i].readPin(2000);

    // check if we are sensing that a finger is touching the pad 
    // and that it wasnt already pressed
    if ((total > THRESH) && (! currentPressed[i])) {
      Serial.print("Key pressed #"); Serial.print(i);
      Serial.print(" ("); Serial.print(Keys[i]); Serial.println(")");
      currentPressed[i] = true;[i]);
    else if ((total <= THRESH) && (currentPressed[i])) {
      // key was released (no touch, and it was pressed before)
      Serial.print("Key released #"); Serial.print(i);
      Serial.print(" ("); Serial.print(Keys[i]); Serial.println(")");
      currentPressed[i] = false;
    // simple lowpass filter to take out some of the jitter
    // change parameter (0 is min, .99 is max) or eliminate to suit
    smoothed[i] = smooth(total, .8, smoothed[i]);   
    Serial.print(i); Serial.print(": ");
    Serial.print( millis() - start);      // time to execute in mS
    Serial.print("ms \t");
    Serial.print(total);                  // raw total
    Serial.println((int) smoothed[i]);       // smoothed

// simple lowpass filter
// requires recycling the output in the "smoothedVal" param
int smooth(int data, float filterVal, float smoothedVal){

  if (filterVal > 1){      // check to make sure param's are within range
    filterVal = .999999;
  else if (filterVal <= 0){
    filterVal = 0;

  smoothedVal = (data * (1 - filterVal)) + (smoothedVal  *  filterVal);

  return (int)smoothedVal;
Open a text editor and test your circuit! It should type keypresses into the editor. If your thread traces are too close together, the buttons could interfere with each other, so be sure to follow the pattern for this project and keep the traces from coming unnessesarily close together! Once you can verify the circuit works its time to turn it into a 3D plush toy.

This guide was first published on Apr 03, 2013. It was last updated on Apr 03, 2013.

This page (The Code) was last updated on Jun 24, 2022.

Text editor powered by tinymce.