first coding i want for the lcd display timer countdown in minutes and second
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x20,20,4); // set the LCD address to 0x27 for a 16 chars and 2 line display
//Counter to change positions of pages
long minutes=0, second =120;
long countdown = (minutes*60)+ second;
long start;
int button = 5; //Enter button
int selectstate = 0; //Set the select to 0, 1 when user press the button.
int led = 13;
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
lcd.init(); // initialize the lcd
// Print a message to the LCD.
lcd.backlight();
pinMode(button, INPUT_PULLUP);
pinMode(led, OUTPUT);
lcd.setCursor(0,0);
lcd.print("HELLO WORLD");
long start = millis();
}
void loop() {
// put your main code here, to run repeatedly:
//count the time has passed
long countdowntime_seconds = 60 - (millis() - start)/1000;
if (countdowntime_seconds >= 0) {
//conversion to min and sec
long countdown_minute = ((countdowntime_seconds / 60) % 60);
long countdown_sec = countdowntime_seconds % 60;
lcd.setCursor(5, 1);
if (countdown_minute < 2) {
lcd.print("0");
}
lcd.print(countdown_minute);
lcd.print(":");
if (countdown_sec < 120) {
lcd.print("0");
}
lcd.print(countdown_sec);
//times up
if (countdowntime_seconds == 0) {
digitalWrite(led, LOW);
}
}
}
second coding i want the part where 2 button with different timer countdown for example button 1 = 1 min and button 2 = 2min
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x20,20,4); // set the LCD address to 0x27 for a 16 chars and 2 line display
int pinButton1 = 5;
int pinButton2 = 4;
int LED = 13;
int timer1 = 5000;
int timer2 = 10000;
void setup()
{
lcd.init(); // initialize the lcd
// Print a message to the LCD.
lcd.backlight();
lcd.setCursor(3,0);
lcd.print("UV LED SYSTEM");
lcd.setCursor(2,1);
lcd.print("DISINFECTION");
delay (2000);
lcd.clear ();
pinMode( LED, OUTPUT );
pinMode( pinButton1, INPUT_PULLUP );
pinMode( pinButton2, INPUT_PULLUP );
long start = millis();
}
void loop()
{
static uint32_t timerStart = 0;
static uint32_t timerDuration = 0;
if ( timerDuration != 0 && millis() - timerStart >= timerDuration )
{
digitalWrite( LED, LOW );
timerDuration = 0;
lcd.print( "LED off" );
}
if ( timerDuration == 0 )
{
if( digitalRead( pinButton1 ) == LOW )
{
timerDuration = timer1;
}
}
else if( digitalRead( pinButton2 ) == LOW )
{
timerDuration = timer2;
}
if ( timerDuration != 0 )
{
digitalWrite( LED, HIGH );
timerStart = millis();
lcd.setCursor(3,0);
lcd.print( "LED on for " );
lcd.print( timerDuration / 1000 );
lcd.setCursor(3,0);
lcd.print( " seconds" );
}
}
i try to combine it but cannot get the result and become more confused.
for the first code it have problem when it simulate the timer countdown is working but led is not on. i though its ok because i just need the countdown coding and the lcd display the countdown coding.
owhhhh because i try to fixed it but can only use simulation because my lcd has problem. someone suggest me to do it with real lcd first but i cannot do it. so i stuck
Do the right thing, if you have enough time. Go back to first principles. Study and understand the display and display code, and the other hardware and code. Then write your own, just use the software you found for hints.
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x20,20,4); // set the LCD address to 0x27 for a 16 chars and 2 line display
//Counter to change positions of pages
long minutes=0, second =60;
long countdown = (minutes*60)+ second;
long start;
int button = 5; //Enter button
int selectstate = 0; //Set the select to 0, 1 when user press the button.
int led = 13;
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
lcd.init(); // initialize the lcd
// Print a message to the LCD.
lcd.backlight();
pinMode(button, INPUT_PULLUP);
pinMode(led, OUTPUT);
lcd.setCursor(0,0);
lcd.print("HELLO WORLD");
long start = millis();
}
void loop() {
// put your main code here, to run repeatedly:
//count the time has passed
long countdowntime_seconds = (millis() - start)/1000;
if (countdowntime_seconds >= 0) {
//conversion to min and sec
long countdown_minute = ((countdowntime_seconds / 60) % 60);
long countdown_sec = countdowntime_seconds % 60;
lcd.setCursor(5, 1);
if (countdown_minute < 2) {
lcd.print("0");
}
lcd.print(countdown_minute);
lcd.print(":");
if (countdown_sec < 120) {
lcd.print("0");
}
lcd.print(countdown_sec);
//times up
if (countdowntime_seconds == 0) {
digitalWrite(led, LOW);
}
}
}
Why use the I2C I/O expander? It complicates things. Connect the LCD directly to the UNO. You still have plenty of I/O left. Know that the analog pins A0 - A3 can be used as digital I/O.
Hi, im having a problem because i confuse how to edit the coding. I found coding that can on the led for 5 second after pressing a push button. but when i want to add another pushbutton to on led for 10 second i become lost. can anyone help me.
int pinButton1 = 5;
int pinButton2 = 4;
int LED = 13;
int timer1 = 5000;
int timer2 = 10000;
void setup(){
pinMode(13,OUTPUT); // LED output
pinMode(5,INPUT); // Button input
pinMode(4,INPUT); // Button input
}
void loop()
{
static unsigned char ledState = LOW;
static unsigned char buttonState1 = LOW;
static unsigned char buttonState2 = LOW;
static unsigned char lastButtonState1 = LOW;
static unsigned char lastButtonState2 = LOW;
static unsigned long ledCameOn = 0;
// If the LED has been on for at least 5 seconds then turn it off.
if(ledState == HIGH)
{
if(millis()-ledCameOn > 5000)
{
digitalWrite(13,LOW);
ledState = LOW;
}
}
// If the button's state has changed, then turn the LED on IF it is not on already.
buttonState = digitalRead(5);
if(buttonState != lastButtonState)
{
lastButtonState = buttonState;
if((buttonState == HIGH) && (ledState == LOW))
{
digitalWrite(13,HIGH);
ledState = HIGH;
ledCameOn = millis();
}
}
}
