inspired by the Arduino Starter Kit example #8: ‚The Digital Hourglass‘, we made a simple tea timer using two pushbuttons to enter two different desired times: 3 minutes and 5 minutes.
After pressing any of the push buttons all 6 LEDs will light up. Each one of the 6 LEDs will be turning off sequentially after an equal interval of time (timer time/6). When the timer reaches the set time, all LEDs will be off and a melody will start playing.
Here is a video showing the timer running for 1 minute (so it is not too long) :
Here is the circuit: the LEDs are connected to pins 2 to 7 of the Arduino, the speaker is connected to pin 9 and the push buttons are connected to the analog input A0:
I have another blog describing the Arduino Starter Kit examples:
To play the melody we were inspired by the Arduino example ‚Play a Melody‘, here is the link to the arduino website : https://www.arduino.cc/en/Tutorial/BuiltInExamples/toneMelody
My daugthter wrote the melody for this example.
Here is the code for the Arduino IDE and the file „pitches.h“:
/*
https://www.arduino.cc/en/Tutorial/BuiltInExamples/toneMelody
*/
#include "pitches.h"
// notes in the melody:
int melody_Sofie[] = {
NOTE_C4, NOTE_G4, NOTE_AS4, NOTE_A4, NOTE_G4,
NOTE_C4, NOTE_G4, NOTE_AS4, NOTE_C5, NOTE_G4,
NOTE_C4, NOTE_G4, NOTE_AS4, NOTE_A4, NOTE_G4, NOTE_F4, NOTE_E4,
NOTE_F4, NOTE_E4, NOTE_C4, NOTE_G3, NOTE_D4,
};
int length = sizeof(melody_Sofie)/2;
// note durations: 4 = quarter note, 8 = eighth note, etc.:
int noteDurations[] = {
4, 4, 4, 4, 1,
4, 4, 4, 4, 1,
4, 4, 4, 4, 4, 4, 1,
4, 4, 2, 8, 1,
};
const int buttonPin = 2;
const int buzzerPin = 9;
int buttonState, prevButtonState, ledNr;
long Interval;
// LEDs are connected from pin 2 to pin 7
void setup() {
Serial.begin(9600);
pinMode(buttonPin, INPUT);
pinMode(buzzerPin, OUTPUT);
ledNr = 2;
for (int x = 2; x < 8; x++) {
pinMode(x, OUTPUT);
}
buttonState = 0;
}
//this function will play a melody
void play_melody (int melody[]){
for (int thisNote = 0; thisNote < 22; thisNote++) {
// to calculate the note duration, take one second divided by the note type.
//e.g. quarter note = 1000 / 4, eighth note = 1000/8, etc.
int noteDuration = 1000 / noteDurations[thisNote];
tone(buzzerPin, melody[thisNote], noteDuration);
// to distinguish the notes, set a minimum time between them.
// the note's duration + 30% seems to work well:
int pauseBetweenNotes = noteDuration * 1.3;
delay(pauseBetweenNotes);
// stop playing:
noTone(buzzerPin);
}
}
//this function will start the LED sequence until all LEDs are off and play the melody
void LED_Timer(long Interv){
unsigned long currentTime= millis();
long ledTime, ledPrvTime, ledInterv;
ledInterv = Interv/6.0;
for (int x = 2; x < 8; x++) {
digitalWrite(x, HIGH);
}
ledTime = millis();
while(millis() < currentTime + Interv){
if(millis() >= ledTime + ledInterv){
ledTime += ledInterv;
digitalWrite(ledNr, LOW);
if (ledNr <= 7){
ledNr++;
}
}
}
digitalWrite(ledNr, LOW);
ledNr = 2;
play_melody(melody_Sofie);
}
void loop() {
unsigned long currentTime, previousTime;
int time_in_ms= 1; // time in ms
int keyVal = analogRead(A0);
//read which button was pressed:
if (keyVal == 1023) {
buttonState = 1;
} else if (keyVal >= 505 && keyVal <= 515) {
buttonState = 2;
}else{
buttonState = 0;
}
//set the timer and call the LED sequence
switch (buttonState){
case 0:
noTone(buzzerPin);
break;
case 1:
time_in_ms = 3*6000; // time in ms for a 3 minutes timer
LED_Timer(time_in_ms);
break;
case 2:
time_in_ms = 5*6000;
LED_Timer(time_in_ms); // time in ms for a 5 minutes timer
break;
}
}
File „pitches.h“:
#define NOTE_B0 31
#define NOTE_C1 33
#define NOTE_CS1 35
#define NOTE_D1 37
#define NOTE_DS1 39
#define NOTE_E1 41
#define NOTE_F1 44
#define NOTE_FS1 46
#define NOTE_G1 49
#define NOTE_GS1 52
#define NOTE_A1 55
#define NOTE_AS1 58
#define NOTE_B1 62
#define NOTE_C2 65
#define NOTE_CS2 69
#define NOTE_D2 73
#define NOTE_DS2 78
#define NOTE_E2 82
#define NOTE_F2 87
#define NOTE_FS2 93
#define NOTE_G2 98
#define NOTE_GS2 104
#define NOTE_A2 110
#define NOTE_AS2 117
#define NOTE_B2 123
#define NOTE_C3 131
#define NOTE_CS3 139
#define NOTE_D3 147
#define NOTE_DS3 156
#define NOTE_E3 165
#define NOTE_F3 175
#define NOTE_FS3 185
#define NOTE_G3 196
#define NOTE_GS3 208
#define NOTE_A3 220
#define NOTE_AS3 233
#define NOTE_B3 247
#define NOTE_C4 262
#define NOTE_CS4 277
#define NOTE_D4 294
#define NOTE_DS4 311
#define NOTE_E4 330
#define NOTE_F4 349
#define NOTE_FS4 370
#define NOTE_G4 392
#define NOTE_GS4 415
#define NOTE_A4 440
#define NOTE_AS4 466
#define NOTE_B4 494
#define NOTE_C5 523
#define NOTE_CS5 554
#define NOTE_D5 587
#define NOTE_DS5 622
#define NOTE_E5 659
#define NOTE_F5 698
#define NOTE_FS5 740
#define NOTE_G5 784
#define NOTE_GS5 831
#define NOTE_A5 880
#define NOTE_AS5 932
#define NOTE_B5 988
#define NOTE_C6 1047
#define NOTE_CS6 1109
#define NOTE_D6 1175
#define NOTE_DS6 1245
#define NOTE_E6 1319
#define NOTE_F6 1397
#define NOTE_FS6 1480
#define NOTE_G6 1568
#define NOTE_GS6 1661
#define NOTE_A6 1760
#define NOTE_AS6 1865
#define NOTE_B6 1976
#define NOTE_C7 2093
#define NOTE_CS7 2217
#define NOTE_D7 2349
#define NOTE_DS7 2489
#define NOTE_E7 2637
#define NOTE_F7 2794
#define NOTE_FS7 2960
#define NOTE_G7 3136
#define NOTE_GS7 3322
#define NOTE_A7 3520
#define NOTE_AS7 3729
#define NOTE_B7 3951
#define NOTE_C8 4186
#define NOTE_CS8 4435
#define NOTE_D8 4699
#define NOTE_DS8 4978
MStronik 