need some help considering While function

Using Arduino Programming Questions
#1

can we do this with the while function while(digitalRead(button)==HIGH && digitalRead(pin1)==LOW)

or does it only apply for one condition ?

#2

does it only apply for one condition

You can have as many conditions as you like combined with && and ||

It is the combined result, true or false, that matters.

#3

I would recommend separating the reading from the testing as it will make it easier to debug by allowing you to print the values that are read - something like this

buttonVal = digitalRead(buttonPin);
pin2Val = digitalRead(pin2);
while (buttonVal == HIGH && pin2Val == LOW) {

Note that I have changed pin1. It is generally not a good idea to use Pins 0 and 1 as they are used for Serial communications.

...R

Edited to change IF to WHILE in response to Reply #3
...R

#4

@robin, you've changed a while to an if. You need to add some advice about how to integrate that logic into the original while. :slight_smile:

#5

aarg:
@robin, you've changed a while to an if. You need to add some advice about how to integrate that logic into the original while. :slight_smile:

Thanks for pointing that out. I will correct the code in Reply #2

...R

#6 
buttonVal = digitalRead(buttonPin);
pin2Val = digitalRead(pin2);
while (buttonVal == HIGH && pin2Val == LOW) {
    //do stuff here
    ...
    buttonVal = digitalRead(buttonPin);
    pin2Val = digitalRead(pin2);
}

Otherwise test result won't change :wink:

#7

Closer to @Robin2's suggestion would be:

boolean buttonVal() { return digitalRead(buttonPin); }
boolean pin2Val { return digitalRead(pin2); }

while (buttonVal() == HIGH && pin2Val() == LOW)
{...}
#8

Personally I don’t like the idea of boolean variables being compared with HIGH/LOW. I know that it works but what is wrong with using byte variables and HIGH/LOW ? To me it makes more sense and eliminates the need to remember whether true/false is the same as HIGH/LOW or is it the other way round ?

#9

UKHeliBob:
Personally I don't like the idea of boolean variables being compared with HIGH/LOW. I know that it works but what is wrong with using byte variables and HIGH/LOW ? To me it makes more sense and eliminates the need to remember whether true/false is the same as HIGH/LOW or is it the other way round ?

Okay, then:

typedef boolean TTL;

TTL buttonVal() { return digitalRead(buttonPin); }
//...etc.

A byte can't be high or low...

#10

To confuse things further digitalRead() returns an int.

#11