Arduino ... a lamp

clear all
3 a = arduino()
4 configurePin(a,'D6','DigitalInput');
5 configurePin(a,'D9','DigitalOutput');
6 configurePin(a,'A0','DigitalInput');
7 k1 = 0;
8 LED = 0;
9 while(true)
10 while(k1)
11 k1 = readDigitalPin(a,'D6');
12 end
13 while(k1 == 0)
14 k1 = readDigitalPin(a,'D6');
15 end
16 if readVoltage(a,'A0') > 2
17 LED = ~LED;
18 else
19 LED = LED;
20 end
21 writeDigitalPin(a, 'D9', LED);
22 end


why cant i change line 10 and 13 with

while(k1 || (K1 == 0))
k1 = readDigitalPin(a,'D6');
end

Answer 1

[Geoff Hayes]

duaa - not quite sure what the error message is but I suspect it has to do with your second condition in

while(k1 || (K1 == 0))

Please note how you are using a capital K instead of a lower case k. The conditions should be

while k1 || (k1 == 0)

[duaa Abdulzahra]

Thank u. So there is no problem with using both ways? Its a led lamp im trying to turn of and on.

[Geoff Hayes]

Please clarify what you mean by both ways. Do you mean the case (upper or lower) for k? Or something else?

[duaa Abdulzahra]

This way:

while(k1)

11 k1 = readDigitalPin(a,'D6');

12 end

13 while(k1 == 0)

14 k1 = readDigitalPin(a,'D6');

15 end

Or this way:

while k1 || (k1 == 0)

k1 = readDigitalPin(a,'D6');

Both work? OR only the first ont? its just for understanding. Im trying to use a button for turning off and on a LED.

[Geoff Hayes]

I would think that both could work but...there may be reason why this was coded the way it was coded. Here is the original code

while(k1)
    k1 = readDigitalPin(a,'D6');
end
while(k1 == 0)
    k1 = readDigitalPin(a,'D6');
end

So there are two while loops where the first one exits if k1 is zero (or negative, if this is possible). Then the second loop exits only if k1 is non-zero.

If we put the two conditions together as

while k1 || (k1 == 0)

then the loop only exits if k1 is negative. And this is the "danger" - if k1 is never negative and so only takes on values of zero or greater, then we could get stuck in this loop and the remainder of the code will never be executed.

Without knowing the pattern of data (via readDigitalPin) from the Arduino, I would recommend leaving the code as is and NOT combining the two loops.

[duaa Abdulzahra]

Super thank you! realy an appreciated answer. Tanks again!