hi all, can you help me,,? I wanted to pin 13 LED blink after pressing the button (1) for 4 times,
and led pin13 blink after pressing the button (2) for 3 seconnd
State change detection (edge detection)
Often, you don't need to know the state of a digital input all the time,
but you just need to know when the input changes from one state to another.
For example, you want to know when a button goes from OFF to ON. This is called
state change detection, or edge detection.
This example shows how to detect when a button or button changes from off to on
and on to off.
The circuit:
* pushbutton attached to pin 2 from +5V
* 10K resistor attached to pin 2 from ground
* LED attached from pin 13 to ground (or use the built-in LED on
most Arduino boards)
created 27 Sep 2005
modified 30 Aug 2011
by Tom Igoe
This example code is in the public domain.
http://www.arduino.cc/en/Tutorial/ButtonStateChange
*/
// this constant won't change:
const int buttonPin = 2; // the pin that the pushbutton is attached to
const int ledPin = 10; // the pin that the LED is attached to
// Variables will change:
int buttonPushCounter = 0; // counter for the number of button presses
int buttonState = 0; // current state of the button
int lastButtonState = 0; // previous state of the button
void setup() {
// initialize the button pin as a input:
pinMode(buttonPin, INPUT);
// initialize the LED as an output:
pinMode(ledPin, OUTPUT);
// initialize serial communication:
Serial.begin(9600);
}
void loop() {
// read the pushbutton input pin:
buttonState = digitalRead(buttonPin);
// compare the buttonState to its previous state
if (buttonState != lastButtonState) {
// if the state has changed, increment the counter
if (buttonState == HIGH) {
// if the current state is HIGH then the button
// wend from off to on:
buttonPushCounter++;
Serial.println("on");
Serial.print("number of button pushes: ");
Serial.println(buttonPushCounter);
} else {
// if the current state is LOW then the button
// wend from on to off:
Serial.println("off");
}
// Delay a little bit to avoid bouncing
delay(50);
}
// save the current state as the last state,
//for next time through the loop
lastButtonState = buttonState;
// turns on the LED every four button pushes by
// checking the modulo of the button push counter.
// the modulo function gives you the remainder of
// the division of two numbers:
if (buttonPushCounter % 3 == 1) {
digitalWrite(ledPin, HIGH);
delay(100);
digitalWrite(ledPin, LOW);
} else {
digitalWrite(ledPin, LOW);
}
}
The code in this link shows how to require a button to be pressed for a period of time
IMHO it would be easier to do
if (buttonPushCounter == 4)
rather than
if (buttonPushCounter % 3 == 1)
Have a look at Planning and Implementing a Program - what you are trying to do will be much easier if you organize the code into small single-purpose functions. And don't use delay() if you want a responsive program.
And please modify your post and use the code button </>
To really check every 4 ticks. But You have a challenge at start thought because buttonPushCounter is 0 and thus its modulo by anything is 0.
Your first case will work because 4 modulo 3 is 1 But then because you don't reset buttonPushCounter, when it gets to 7 the modulo will be 1 so you trigger after 3 clicks, then at 10...
Also another good reason fo resetting it is that it will grow past 32768 and turn negative if you use the program long enough
Your serial.print will be super long compared the the debounce you have in there. Be aware that at 9600 bauds that can cause weird behaviors if you rely on quick action.
the lights can not be turned again after a 4x push,, must first press the reset button
You need to post the complete program that you wrote taking account of the code in the link I gave you. The link was not intended to meet your complete requirement - I thought I should leave a little work for you.
fathur:
I change like this, how to stop the blink, I want to just 1x blink
[/code]
Just push the button again
Seriously though, just keep a counter to count the number of flashes. When you reach the number of flashes (5 in below example to differentiate from the 4 pushes on the button), reset whatever needs to be reset.
void loop()
{
static byte flashcounter = 0; // <------ ADD THIS at the beginning from loop()
// existing code
...
...
// your code to flash the led; modified
if (buttonPushCounter == 4)
{
digitalWrite(ledPin, HIGH);
delay(100);
digitalWrite(ledPin, LOW);
delay(100);
// count number of flashes
flashcounter++; // <------ ADD THIS and the following if block
if(flashcounter >= 5)
{
// reset flash counter
flashcounter = 0;
// reset button push counter
buttonPushCounter = 0;
}
}
else
{
digitalWrite(ledPin, LOW);
}
}
And as Robin said; in future please post the complete code.
