Trinket sketch to build a react or 'like' button that counts button presses and displays them on a 7-segment or 14-segment LED backpack.
You need the following hardware to build this device:
Usage
Load the right sketch in Arduino depending on your hardware. The 7-segment display should use the TrinketReactCounter_7segment sketch, and the 14-segment quad alphanumeric display should use the TrinketReactCounter_14segment sketch. Make sure the following libraries are installed too (using the library manager or a manual install):
// SPDX-FileCopyrightText: 2019 Tony DiCola for Adafruit Industries
//
// SPDX-License-Identifier: MIT
// Adafruit Trinket React Counter Sketch - 7-segment display
//
// Use a 7-segment LED backpack to display the number of times a
// button has been pressed. Great for building a physical 'like'
// or react button. The value will be stored in EEPROM so it
// will persist between power down/up.
//
// NOTE: As-is this sketch needs to run on a Trinket because it
// assumes the switch on pin #1 has a pull-down resistor to ground.
// If using another board without this pull-down you can explicitly
// add a ~10kohm resistor from digital #1 to ground.
//
// Author: Tony DiCola
// License: MIT (https://opensource.org/licenses/MIT)
#include <EEPROM.h>
#include <Wire.h>
#include "Adafruit_LEDBackpack.h"
#include "Adafruit_GFX.h"
// Uncomment the line below to reset the counter value in EEPROM to zero.
// After uncommenting reload the sketch and during the setup the counter
// will be reset. Then comment the line again and reload to start again
// (if you don't comment it out then every time the board powers on it
// will reset back to zero!).
//#define RESET_COUNT
// OR just hold the button for longer than the RESET_HOLD_SECOND below
// to reset the count!
// Configuration:
#define LED_BACKPACK_ADDRESS 0x70 // I2C address of the backpack display.
// Keep the default 0x70 unless you
// change the backpack's address bridges.
#define COUNT_BUTTON_PIN 1 // Digital input connected to the button that
// will increase the count. This line should
// have a pull-down resistor to ground. The
// opposite side of the button should be
// connected to a high level like 5V or 3.3V.
#define COUNT_ADDRESS 0 // Address in EEPROM to store the counter.
// This will take 2 bytes (16-bit value).
// You don't need to change this unless you
// want to play with different EEPROM locations.
#define RESET_HOLD_SECONDS 5 // Number of seconds to hold the button down to
// force a reset of the count to zero. Set to 0
// to disable this functionality.
// 7-segment display
Adafruit_7segment backpack = Adafruit_7segment();
uint32_t holdStart = 0;
void update_display() {
// Get the count value from EEPROM and print it to the display.
uint16_t count;
EEPROM.get(COUNT_ADDRESS, count);
backpack.print(count, DEC);
backpack.writeDisplay();
}
void setup() {
// Setup button inputs.
pinMode(COUNT_BUTTON_PIN, INPUT);
// Initialize the LED backpack display.
backpack.begin(LED_BACKPACK_ADDRESS);
// Clear the count in EEPROM if desired.
#ifdef RESET_COUNT
uint16_t count = 0;
EEPROM.put(COUNT_ADDRESS, count);
#endif
// Update the display with the current count value.
update_display();
// Reset the last known time the button wasn't being held.
holdStart = millis();
}
void loop() {
// Take a couple button readings with a small delay in between to detect when
// the signal changes from high to low, i.e. the button was released.
int firstCount = digitalRead(COUNT_BUTTON_PIN);
delay(20);
int secondCount = digitalRead(COUNT_BUTTON_PIN);
// Check for count button release.
if (firstCount == HIGH && secondCount == LOW) {
// Button was released!
// Increment the count value stored in EEPROM.
uint16_t count;
EEPROM.get(COUNT_ADDRESS, count);
count += 1;
EEPROM.put(COUNT_ADDRESS, count);
// Update the display with the latest count value.
update_display();
}
// Reset the hold start if the button wasn't pressed (i.e. first and last were not both high levels).
if ((firstCount != HIGH) || (secondCount != HIGH)) {
holdStart = millis();
}
// Check if the button has been held for the amount of reset time.
if ((RESET_HOLD_SECONDS > 0) && ((millis() - holdStart) >= (RESET_HOLD_SECONDS*1000))) {
// Reset to zero and update the display!
uint16_t count = 0;
EEPROM.put(COUNT_ADDRESS, count);
update_display();
// Reset the hold time to start over again.
holdStart = millis();
// Flash the display a few times to give time to remove finger.
for (int i=0; i<5; ++i) {
delay(200);
backpack.clear();
backpack.writeDisplay();
delay(200);
update_display();
}
}
}
// SPDX-FileCopyrightText: 2019 Tony DiCola for Adafruit Industries
//
// SPDX-License-Identifier: MIT
// Adafruit Trinket React Counter Sketch - 14-segment quad alpha display
//
// Use a 14-segment quad alphanumeric LED backpack to display the
// number of times a button has been pressed. Great for building
// a physical 'like' or react button. The value will be stored
// in EEPROM so it will persist between power down/up.
//
// NOTE: As-is this sketch needs to run on a Trinket because it
// assumes the switch on pin #1 has a pull-down resistor to ground.
// If using another board without this pull-down you can explicitly
// add a ~10kohm resistor from digital #1 to ground.
//
// Author: Tony DiCola
// License: MIT (https://opensource.org/licenses/MIT)
#include <EEPROM.h>
#include <Wire.h>
#include "Adafruit_LEDBackpack.h"
#include "Adafruit_GFX.h"
// Uncomment the line below to reset the counter value in EEPROM to zero.
// After uncommenting reload the sketch and during the setup the counter
// will be reset. Then comment the line again and reload to start again
// (if you don't comment it out then every time the board powers on it
// will reset back to zero!).
//#define RESET_COUNT
// OR just hold the button for longer than the RESET_HOLD_SECOND below
// to reset the count!
// Configuration:
#define LED_BACKPACK_ADDRESS 0x70 // I2C address of the backpack display.
// Keep the default 0x70 unless you
// change the backpack's address bridges.
#define COUNT_BUTTON_PIN 1 // Digital input connected to the button that
// will increase the count. This line should
// have a pull-down resistor to ground. The
// opposite side of the button should be
// connected to a high level like 5V or 3.3V.
#define COUNT_ADDRESS 0 // Address in EEPROM to store the counter.
// This will take 2 bytes (16-bit value).
// You don't need to change this unless you
// want to play with different EEPROM locations.
#define RESET_HOLD_SECONDS 5 // Number of seconds to hold the button down to
// force a reset of the count to zero. Set to 0
// to disable this functionality.
// 14-segment quad alphanumeric display
Adafruit_AlphaNum4 backpack = Adafruit_AlphaNum4();
uint32_t holdStart = 0;
void update_display() {
// Get the count value from EEPROM and print it to the display.
uint16_t count;
EEPROM.get(COUNT_ADDRESS, count);
// Use writeDigitRaw function to write out each digit for the thousands,
// hundreds, tens, and ones place.
int thousands = count / 1000;
int remainder = count % 1000;
int hundreds = remainder / 100;
remainder = remainder % 100;
int tens = remainder / 10;
remainder = remainder % 10;
// Check if the value is too large to display and just print dashes.
if (thousands >= 10) {
backpack.writeDigitAscii(0, '-');
backpack.writeDigitAscii(1, '-');
backpack.writeDigitAscii(2, '-');
backpack.writeDigitAscii(3, '-');
}
else
{
// Print out the number starting from the first non-zero digit.
if (thousands > 0) {
backpack.writeDigitAscii(0, '0'+thousands);
backpack.writeDigitAscii(1, '0'+hundreds);
backpack.writeDigitAscii(2, '0'+tens);
backpack.writeDigitAscii(3, '0'+remainder);
}
else if (hundreds > 0) {
backpack.writeDigitAscii(1, '0'+hundreds);
backpack.writeDigitAscii(2, '0'+tens);
backpack.writeDigitAscii(3, '0'+remainder);
}
else if (tens > 0) {
backpack.writeDigitAscii(2, '0'+tens);
backpack.writeDigitAscii(3, '0'+remainder);
}
else {
backpack.writeDigitAscii(3, '0'+remainder);
}
}
backpack.writeDisplay();
}
void setup() {
// Setup button inputs.
pinMode(COUNT_BUTTON_PIN, INPUT);
// Initialize the LED backpack display.
backpack.begin(LED_BACKPACK_ADDRESS);
// Clear the count in EEPROM if desired.
#ifdef RESET_COUNT
uint16_t count = 0;
EEPROM.put(COUNT_ADDRESS, count);
#endif
// Update the display with the current count value.
update_display();
// Reset the last known time the button wasn't being held.
holdStart = millis();
}
void loop() {
// Take a couple button readings with a small delay in between to detect when
// the signal changes from high to low, i.e. the button was released.
int firstCount = digitalRead(COUNT_BUTTON_PIN);
delay(20);
int secondCount = digitalRead(COUNT_BUTTON_PIN);
// Check for count button release.
if (firstCount == HIGH && secondCount == LOW) {
// Button was released!
// Increment the count value stored in EEPROM.
uint16_t count;
EEPROM.get(COUNT_ADDRESS, count);
count += 1;
EEPROM.put(COUNT_ADDRESS, count);
// Update the display with the latest count value.
update_display();
}
// Reset the hold start if the button wasn't pressed (i.e. first and last were not both high levels).
if ((firstCount != HIGH) || (secondCount != HIGH)) {
holdStart = millis();
}
// Check if the button has been held for the amount of reset time.
if ((RESET_HOLD_SECONDS > 0) && ((millis() - holdStart) >= (RESET_HOLD_SECONDS*1000))) {
// Reset to zero and update the display!
uint16_t count = 0;
EEPROM.put(COUNT_ADDRESS, count);
update_display();
// Reset the hold time to start over again.
holdStart = millis();
// Flash the display a few times to give time to remove finger.
for (int i=0; i<5; ++i) {
delay(200);
backpack.clear();
backpack.writeDisplay();
delay(200);
update_display();
}
}
}
