Arduino thinking to quickly - variables

Question

I am trying to get a rgb colour LED to change through each color every button push. I am having a hard time because the arduino is processing to fast. I want it to wait for the button to be let go before changing the variable "state". What it does right now is that when the button is pressed, it immediately changes the state from 1 to 2 to 3. I want it to change only when i let go of the button. Thank you for trying.
int pushButton = 7;
int r = 2;
int g = 3;
int b = 4;
void setup() {
Serial.begin(9600);
pinMode(pushButton, INPUT);
}
void loop() {
int state = digitalRead(pushButton);
if (state == 1) {
digitalWrite(r, HIGH);
state = state + 1;
}
if (state == 2) {
digitalWrite(b, HIGH);
digitalWrite(r, LOW);
state = state + 2;
}
if (state == 3) {
digitalWrite(b, LOW);
digitalWrite(r, LOW);
digitalWrite(g, HIGH);
}
if (state == 0) {
digitalWrite(r, LOW);
digitalWrite(b, LOW);
digitalWrite(g, LOW);
}
Serial.println(state);
delay(1);
}

Answer 1

First yo have to recognize the button state change correctly.
You can use a library like ClickButton or write your own. Have a look at the Arduino Example for button change state.
Once, you have a correct button state recognition, you can realize your LED behavior quite easily using conditions (switch, if-else, etc.)

Answer 2

The easiest way is just to grab the current state of the button and compare it to the previous state of the button. If they are different, then the button state has changed, and you can respond accordingly.
Something like:
int prevButtonState = 0;
void loop()
{
int buttonState = digitalRead(pushButton);
if (buttonState != prevButtonState)
{
// Button state has changed - do something useful
// ...
prevButtonState = buttonState;
}
}

Answer 3

In Arduino, the loop is something that is supposed to run continuously.
Additionally, the output of digitalRead(int) is the constant value LOW and HIGH,
which happen to be defined as 0 and 1.
In your loop there are 2 cases: state = LOW = 0 or state = HIGH = 1
First Case state = 0:
In this case only the final if statement matches the value of state, and is the only if that
runs, which turns the light off. Then the rest of loop() runs printing 0.
Second Case state = 1:
In this case the first if statement runs. The light turns red and state is increased by
1, so that state = 2. There is nothing stopping the code from continuing so it
immediately goes to the next if statement.
The second if statement matches because state is 2. The if statement runs. The light
becomes blue. Also, state becomes 4. The code continues to run.
The third and fourth if statements should not run because state is 4. The light should remain blue and 4 should be outputted.
In either case, the loop continuously runs.
Suggestions:
- the variable state should be global
- there should be a global variable lastButtonState intialized to LOW
Code:
loop () {
int buttonState = digitalRead(pushButton);
if (buttonState != lastButtonState) { // a change
if (buttonState == LOW) { // button realeased
state = state + 1;
if (state >= 4) state = 0;
}
}
lastButtonState = buttonState;
...
You can keep the rest of the code, but remove the state = state + <number>; lines.
This is just a start.