This is an easy to build pet feeder with two timers. Delivers accurate portions each time. At first glance you may doubt the usefulness of this function. This will happen if you leave your Arduino board running for 4,294,967,295mS i.e. A well known Arduino function is delay() which pauses the program for an amount of milliseconds specified as parameter.. millis(), on the other hand, is a function that returns the amount of milliseconds that have passed since program start. We can set up a timer to interrupt us once per millisecond. millis() Tutorial: Arduino Multitasking by James Lewis. That is millis() will start counting from 0 again. Each function works when run individually, now I'm trying to combine both into the project. Now let's consider another way of coding the test (millis() - delayStart) >= 10000. The end user use all these applications at the same time but OS takes this concept a bit different. The timer will actually call us to let us know it is time to check the clock! Nach ca. That is millis() will start counting from 0 again. Häufige Fehlerquelle: Da millis() relativ schnell über den Wertebereich int hinauslaufen, sollte man hier den Variablentyp long bevorzugen. Arithmetically this test is equal to millis() >= (delayStart + 10000) This kind of operating systems are known as MOS (multitasking operating system). Timer0 is already set up to generate a millisecond interrupt to update the millisecond counter reported by millis(). The fact is that it’s extremely useful in many scenarios, often “replacing” If you want your code to just pause for 1000 ms at the end of each loop iteration, the code above is a bit silly. Now let's consider another way of coding the test (millis() - delayStart) >= 10000 Arithmetically this test is equal to millis() >= (delayStart + 10000) You are able to run other code simultaneously as well.More importantly: to learn how you can avoid the overflow issue alltogether, read Note that it is recommended to use The interrupt subroutine is written and it will only change the Loop starts with storing the millis value in a currentMillis variable which will store the value of time elapsed every time the loop iterates.int ledState1 = LOW;  // to determine the states of led1 and led2unsigned long previousMillis1 = 0;  //store last time LED1 was blinkedunsigned long previousMillis2 = 0;  //store last time LED2 was blinkedint debouncePeriod = 20;            // debounce delay of 20msbool buttonPushed = false;     // interrupt routine button status   if (currentMillis - previousMillis1 >= period1) {    // check if 1000ms passed  if (currentMillis - previousMillis2 >= period2) { // check if 1000ms passed  if (buttonPushed = true)    // check if ISR is calledSubscribe below to receive most popular news, articles and DIY projects from Circuit DigestSensor interfacing for IoT edge nodes, wearables, lighting, automotive, and factory automation.The 8-bit MCUs feature improved sensor interfacing capabilities for real-time control applications.Microchip’s 8-bit AVR DA MCUs enable real-time control, connectivity, and HMI applications.The IOT-HOME-KIT-ND development kit is geared towards smart IoT home automation applications.16-bit MCUs with several core independent peripherals (CIPs), segmented LCD and USB functionality.The EV15R70A is Microchip’s Amazon Web Services (AWS) Cloud IoT development solution.The EV54Y39A from Microchip is a secure Amazon Web Services (AWS) Cloud IoT development solution.MCP6V7X low power 2 MHz zero-drift operational amplifiers provide input offset voltage correction.Connect with us on social media and stay updated with latest news, articles and projects!