imranahmed
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void modeChange() {
mode++;
if(mode == 9)
{
mode = INIT_MODE;
}
}
void modeChange() {
mode++;
if(mode == 9)
{
mode = INIT_MODE;
}
if(autoLight == 1)
{
lastTimeOut = millis();
lcd.backlight();
lcd.display();
autoLight = 0;
}
}
You are not doing the right way, no function should be placed inside interrupt handler.
Put the above snippet ( "if(autoLight..." ) within the loop() function.
/Interrupts using Arduino
//Circuit Digest
#include<LiquidCrystal.h> // Including lcd display library
LiquidCrystal lcd (7,8,9,10,11,12); // Define LCD display pins RS,E,D4,D5,D6,D7
volatile int output = LOW;
int i = 0;
void setup()
{
lcd.begin(16,2); // setting LCD as 16x2 type
lcd.setCursor(0,0);
lcd.print("CIRCUIT DIGEST");
lcd.setCursor(0,1);
lcd.print("ArduinoInterrupt");
delay(3000);
lcd.clear();
pinMode(13,OUTPUT);
attachInterrupt(digitalPinToInterrupt(2),buttonPressed1,FALLING); // function for creating external interrupts at pin2 on Falling (HIGH to LOW)
attachInterrupt(digitalPinToInterrupt(3),buttonPressed2,FALLING); // function for creating external interrupts at pin3 on Flling (HIGH to LOW)
}
void loop()
{
lcd.clear();
lcd.print("COUNTER:");
lcd.print(i);
++i;
delay(1000);
digitalWrite(13,output); //Turns LED ON or OFF depending upon output value
}
void buttonPressed1() //ISR function excutes when push button at pinD2 is pressed
{
output = LOW; //Change Output value to LOW
lcd.setCursor(0,1);
lcd.print("Interrupt 1");
}
void buttonPressed2() //ISR function excutes when push button at pinD3 is pressed
{
output = HIGH; //Change Output value to HIGH
lcd.setCursor(0,1);
lcd.print("Interrupt2");
}
Please see above code copy from CircuitDigest website, I followed same thing as they did.
for debounce I usedReview above reply, I didn't mean to add the whole code within loop(), but rather the snippet if(autoLight == 1) { ... }
Anyway, don't rely on everything you see on the Web. BTW, are you providing any kind of hardware debounce for the button, e.g RC ?
if (millis() - lastFire < 300) { // Debounce
return;
}
lastFire = millis();
Thanks bro it is working. Volatile is very important today I know it. Again Thanks.variables used in ISR that are not local to ISR should be declared as "volatile"
How to Use C’s Volatile Keyword
The proper use of C's volatile keyword is poorly understood by many programmers. This is not surprising, as most C texts dismiss it in a sentence or two. This article will teach you the proper way to do it.barrgroup.com
Regards, Dana.
volatile unsigned long count = 0;
volatile unsigned long prev_count = 0;
const byte int_0_pin = 2;
void setup() {
Serial.begin(9600);
pinMode(int_0_pin, INPUT_PULLUP);
interrupts();
attachInterrupt(digitalPinToInterrupt(int_0_pin), countInt0,CHANGE);
}
void loop() {
if(count > prev_count){
Serial.println(count);
prev_count = count;
}
}
void countInt0(){
count++;
}
long is 8 bytesHi,
"count" is declared as "long". How many bytes is a "long"?
Klaus
Sorry for Arduino it is 4 byteslong is 8 bytes
I set baud rate 9600 means 9600 bits per second it sends 4 bytes of count 1 byte of CR and 1 byte of LF.Hi,
so with each count tick you send 8 bytes + CR + LF. Is this correct?
How long does it take for the UART to transmit 8 bytes + CR + LF?
Klaus
Where does 1.08 x 10^-8 come from?Total bits send = 48 bits
9600 bits takes 104us , 1 bit takes 1.08x10^-8 seconds multiply by 48 it will 0.00000052 seconds.
Is this right?
Ohhh I see 104us is for 1 bit transfer time for 9600 baud rate.Where does 1.08 x 10^-8 come from?
Neither 1.08 is clear, nor 10^-8.
1 us = 1 microsecond = 1 x 10^-6 s. = 0.000001s
104us = 104 x 10^-6 s = 1.04 x 10^-4 s = 0.000104s
48 bit means 48 x 1.04 x 10^-4 s = 49.92 x 10^-4 s = 0.004992s = 4.99ms
You had at least 3 mistakes in this simple math.
You really need to learn this, because you will need this all the time when you want to write programs.
This also means it fits about 200 times in one second.
So not 800Hz is the limit, but 200Hz
Klaus
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