9/11/2023 0 Comments Arduino button press![]() Remember that the processor is very fast and it can go through the loop in a time measured in microseconds. As we get into the program, we call millis() store its value in tNow. When the program first starts, the value of tLED (time LED) is set to the value of millis() in setup. The current value is placed in the variable tNow (which means "time Now"). It doesn't matter what its absolute value is because we're only interested in the change from one reading to the next. Here we read the number of milliseconds that has passed since the Arduino reset. Let's look at the sections of loop(): void loop() if button is pushed, print to the serial monitorÄo you understand what this is doing? Can you see how you might apply the principle to your own code? yes we want to save the new count to time the next blink ![]() Here's a slight variation of your code that illustrated blinking an LED while also checking the user button in real time: const uint8_t LED1 = 3 If you keep track of the first read (let's call the variable tLED) and keep calling millis() and storing the value in another variable (let's call it tNow) then you can time things. A 32-bit unsigned number can be as large as 4,294,967,295 which is a lot of milliseconds (almost 50-days' worth.) If you call millis() at a given time T, then at T+1-second if you call millis() again the value returned will be 1000 higher than the first read. When you call this function, it returns a 32-bit number that represents the number of milliseconds that have elapsed since the program first started running. ![]() To do this, we often use the millis() function. So you need to find a way to blink the pattern without using the delay() function so the processor can do other things, like checking the button input. The delay() function is what's known as a "blocking function" except for interrupts, nothing else happens while the delay() function runs, including reading of inputs like buttons. This is because you use the delay() function to wait for 1-second for each stage of you blinking sequence. One problem you're going to face is once you're started the LEDs blinking (buttonState = HIGH) it will have to finish doing those blinks - 6 seconds - before the switch is read again. ![]()
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