Toggle switch on Arduino

Using Arduino LEDs and Multiplexing
1

Hi,

I'm using toggle switch with arduino and I want to achieve press button (only once) when toggle switch is active:

   if(digitalRead(7) == 0)
    {
      Keyboard.write('7');
      delay(200);
      if(digitalRead(7) != 0)
        {
          Keyboard.releaseAll();
        }      
    }

but in this scenario button is constantly pressed. How to achieve that button will be pressed only once, but same time toggle switch is active?

2

Please slow down and tell us what your requirements are ?

Always show us a good schematic of your proposed circuit.
Show us a good image of your ‘actual’ wiring.
Give links to components.

1 Like
3

try using a flag

4

I'm ussing toggle switch to type a '7' when button is active. But he keeps repeating the same "7". What I want to achieve is that it will only type or press once even if the switch is active. I edited the code I added.

5 
bool state=0;

if(digitalRead(7) == 0 && state==0)
    {
      Keyboard.write('7');
      state=1;
      delay(50);
   }

      if(digitalRead(7) != 0)
        {
          Keyboard.releaseAll();
          state=0;
        }

This should work as you said

6

Post the complete sketch to see how we can help.

7

Can you post a small schematic showing the button/switch and how it is wired. Please include all power sources.

8

To many braces }

9

Oops . i fixed it. Thanks

10

We do not know your complete program, if blocking for the time you press the button is ok, this would do it also

if(digitalRead(7) == 0)
    {
      Keyboard.write('7');
      delay(20);  //Poor man's debouncing 
      Keyboard.releaseAll();  
      while(digitalRead(7) == 0) {}; \\Wait until button released 
    }
11

It worked, thank you.
But why it is not working with if inside if?:

bool state=0;

if(digitalRead(7) == 0 && state==0)
    {
      Keyboard.write('7');
      state=1;
      delay(50);
      if(digitalRead(7) != 0)
        {
          Keyboard.releaseAll();
          state=0;
        }      
   }

I'm just curious.

12

Here I first initialise a variable name "state".
Now if(digitalRead(7) == 0 && state==0) checks if you have pressed the button on pin 7 and the state== 0 assure that this is first time functions is executing. After that the state=1 represent that the function Keyboard.write('7') has already executed. And the statement if(digitalRead(7) == 0 && state==0) is no longer true.

Now when you release the button the second statement if(digitalRead(7) != 0) reset state to 0. And the loop continues.

That because only one statement can be true at a time. Either digitalRead(7) != 0 or digitalRead(7) == 0

1 Like
13

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