Now I had accomplished something with the LED and button. This will change next time the button is pressed. This is to make sure that there is no difference later (last != current) on when the code repeats. Finally, the most important part is to make sure the lastButton = currentButton.it has been pressed), then change the led state This state of the button is 'returned' into the main loop where the state of the button is checked to make sure it is low (i.e.If it has, it will reread the button in 5 milliseconds and declare that to be the state of the button.A boolean debounce function (which calls the previous state of the button) checks to see whether the button has changed state.These don't need to be set at the start because they will be varied throughout the code excepet LedOn which makes sure the led stays off at the start. One for last button state, current button state and ledOn. 5 milliseconds is plenty of time for you to remove your finger from the button (you can't press it faster). This example is based on Jeremy Blum's 'debounce' LED function which compares, the button state again after 5 milliseconds to see if it was really pressed (as compared to noise on the button). This can only read after you have taken your finger off. This is because it activates a millis() timng which compares the press to a set time. The reason I chose this 'debounce' program was because the Arduino 'debounce' program does not change the state of the button until you have taken your finger off the button, so it is too slow. Getting the LED to remain on when pressed requires a little bit more work than you would think. ![]() Pressing a button and the LED lights up is fun, but most of the time you want it to remain in that state. This is useful when you have a long and complex programme, we can then simplify it by calling smaller parts to runĪrduino Example 3 & 4 - Button for LED On/Off
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |