Hi Guys.
I'm starting to study the Millis() function using simple code on and off with delay.
I've watched a lot of videos but still struggling to understand the Millis() function.
I want to start to understand how Millis work using Led on and off.
but i want to control the timing or the duration of the led off and on time.
ive found many post code and try to understand the code but still even if, i edit the duration time its not giving me the right result that i expect there still a problem.
can you please code this from using delay to millis?
I hope you can help me.
I'm just begginer and trying to learn.
thanks in advance guys.
LED 1 = 13;
LED 2 = 12;
void setup() {
// initialize digital pin LED_BUILTIN as an output.
pinMode(LED 1, OUTPUT);
pinMode(LED 2, OUTPUT);
}
// the loop function runs over and over again forever
void loop() {`Preformatted text`
digitalWrite(LED 1, HIGH); // turn the LED on (HIGH is the voltage level)
delay(500); // wait for a second
digitalWrite(LED 1, LOW); // turn the LED off by making the voltage LOW
delay(3000); // wait for a second
}
digitalWrite(LED 2, HIGH); // turn the LED on (HIGH is the voltage level)
delay(60000); // wait for a second
digitalWrite(LED 2, LOW); // turn the LED off by making the voltage LOW
delay(10000); // wait for a second
}
}
Good attempt at posting code using code tags but as you might have noticed, it did not quite work out. </> is a button in the reply window of the forum, not something you must type
Edit your post, remove that, select all code and click the </> button. Next save your post
==
LED 1 = 13 is incorrect syntax; look at the blink example how it is done. Same for LED 2 = 12.
Spaces aren't allowed in names ("identifiers"). You can use letters, digits, and unserscore characters. If you want something that looks like a space, use underscore:
Get used to auto formatting using ctrl-T. It shows the block indentation, here you can see another reason why your code won't compile:
LED 1 = 13;
LED 2 = 12;
void setup() {
// initialize digital pin LED_BUILTIN as an output.
pinMode(LED 1, OUTPUT);
pinMode(LED 2, OUTPUT);
}
// the loop function runs over and over again forever
void loop() {
`Preformatted text`
digitalWrite(LED 1, HIGH); // turn the LED on (HIGH is the voltage level)
delay(500); // wait for a second
digitalWrite(LED 1, LOW); // turn the LED off by making the voltage LOW
delay(3000); // wait for a second
}
digitalWrite(LED 2, HIGH); // turn the LED on (HIGH is the voltage level)
delay(60000); // wait for a second
digitalWrite(LED 2, LOW); // turn the LED off by making the voltage LOW
delay(10000); // wait for a second
}
}
The loop() ending problem was mentioned in reply #3.
Work like ... when you write this line, millis function take the amount of millisecond from the time you turn on the Arduino. The variable "time" are unsigned long variable. A 4 byte number. A number from 0 to 4,294,967,295. When it reach the end, it will start from 0.
Let take an example ...
Let say you just start the Arduino and the code see this ... my_time = millis( ); So my_time will have the number ---> 10. And the code do other stuff, and when it read again the line, the number will be ---> 21. And repeat .... As you see, the number 10 ( the old value ) versus number 21 ( the new value ) have a difference of 11. So to make a delay of 1000, you need a difference of 1000 or above. When it reach the 1000 difference, you re-init the old value, and you compare with the "new" old value with a regular millis check, until you got again the 1000 difference, and repeat the cycle.
Let take the blink code
byte light = 5; // Let connect a led to pin 5 with a 470 ohms resistor.
void setup()
{
pinMode(light, OUTPUT);
}
void loop()
{
digitalWrite(light, HIGH);
delay(1000);
digitalWrite(light, LOW);
delay(1000);
}
Now with the use of millis()
byte light = 5; // connect a led to pin 5
boolean light_state; // the state of the led
unsigned long old_time;
unsigned long check_time;
unsigned long time_difference;
unsigned long time_delay = 1000; // the time delay you want.
void setup()
{
pinMode(light, OUTPUT);
old_time = millis(); // check the time as now.
digitalWrite(light, HIGH); // Turn the led on
light_state = true; // set the state to on.
}
void loop()
{
check_time = millis(); // check the time now
time_difference = old_time - check_time; // calculate the time difference
// check the time difference is equal or more than 1000 AND the state of the led is ON
if ( (time_difference >= time_delay) && ( light_state == true))
{
digitalWrite(light, LOW); // turn off the led
light_state = false; // change the state of the led.
old_time = millis(); // re-init the time
}
// check the time_difference is equal or more than 1000 AND the state of led is off
if ( (time_difference >= time_delay) && ( light_state == false))
{
digitalWrite(light, HIGH); // turn on the led
light_state = true; // change the state of the led.
old_time = millis(); // re-init the time
}
}
