I'm new to programming and I can't get my head around this problem I'm trying to figure out, I thought it would be a simple program but obviously way pass my knowledge level... If it is as easy as i thought i would be can someone write the program and a quick explanation of how it works so i can learn from this? What i'm trying to do is control an egg turner without using any delay() so basically i wanna add limit switches at each end so when it hits the limit switch, it will pause for an hour then resume turning to motor till it reaches the other end and hit the limit switch and pause for an hour and continue that process forever. The egg turner motor keeps spinning in one direction with a lever that makes the egg trays rock back and forth so i don't need it to reverse the motor, just to resume after an hour. i get totally lost when i'm trying to figure out what the program should be doing while its at one end holding that limit switch in a high state. I can't write the switch low while its being held pressed high by the egg turner... my plan is to use Arduino nano, relays, and micro limit switches that can be wire either normally open or normally closed. anyone know how this can be done? Total noob here so I apologize in advance if this is actually simple , I've been reading on limit switches and egg turner programming and a lot of ppl just use timers but its not very precise... they eventually go out of sync and don't rotate perfectly 45 degrees to one side then 45 to the other side. plz help! this is one challenge that is kicking my behind. I swear i'm laying in bed trying to figure this out and my wife thinks i'm thinking of other women lol

@datfreak - I built your project using the code in #59. I added printing and did remove the test on buttonPushCounter: anything modulo 1 is 0, so basically the loop always turns on the motor, and only the button going down turns it off and wastes time. I'm older so I further cut your 2000 ms delay down to size to just 1000 milliseconds. But I am glad you got that trick out of the way - we see ppl working on stuff that literally takes days to test if you don't let your impatience spur creativity. Note also that the delay is placed so as to come into effect on both edges. If the delay were indeed an hour this would become painfully obvious at some point. I added the yellow LED to show when the delay was, um, delaying. Try changing the delay time up to 10 or 20 seconds and see what might otherwise have been a silent mystery. Off busy busy wasting time... Simulation, try it: [image] firstCrackAtIt - Wokwi ESP32, STM32, Arduino Simulator Run IoT and embedded projects in your browser: ESP32, STM32, Arduino, Pi Pico, and more. No installation required! Code: // https://wokwi.com/projects/426758656203619329 const int limitSwitch1 = 8; const int relay1 = 10; int buttonPushCounter = 0; // counter for the number of button presses int buttonState = 0; int lastButtonState = 1; //... normally reads high, so int wastingBlind = 11; void setup() { //... how do you get along without: Serial.begin(115200); Serial.println("\nHey!\n"); pinMode(limitSwitch1, INPUT_PULLUP); pinMode(relay1, OUTPUT); pinMode(wastingBlind, OUTPUT); } # define ON HIGH # define OFF LOW void loop() { buttonState = digitalRead(limitSwitch1); if (buttonState != lastButtonState) { if (buttonState == HIGH) { buttonPushCounter++; } else { digitalWrite(relay1, OFF); Serial.println(" limit hit, turned off."); } Serial.print(buttonPushCounter); Serial.print(" "); Serial.println("edge. hanging out Boss!"); //... show when we are wasting time and blind to input digitalWrite(wastingBlind, HIGH); delay(1000); digitalWrite(wastingBlind, LOW); } lastButtonState = buttonState; //... anything modulo 1 is zero // if (buttonPushCounter % 1 == 0) { digitalWrite(relay1, ON); // } } HTH a7

servo or stepper would be so much easier, but these egg turners came with motors and all and this is also a learning opportunity to get this to work with a motor that keeps turning in one direction. It's a challenge that is bugging me as a noob and I'm determined to figure this out.

[20250329_124559] [20250329_124618] [20250329_124559] [image] datfreak: I'm new to programming and I can't get my head around this problem I'm trying to figure out, I thought it would be a simple program but obviously way pass my knowledge level... If it is as easy as i thought i would be can someone write the program and a quick explanation of how it works so i can learn from this? What i'm trying to do is control an egg turner without using any delay() so basically i wanna add limit switches at each end so when it hits the limit switch, it will pause for an hour then resume turning to motor till it reaches the other end and hit the limit switch and pause for an hour and continue that process forever. The egg turner motor keeps spinning in one direction with a lever that makes the egg trays rock back and forth so i don't need it to reverse the motor, just to resume after an hour. i get totally lost when i'm trying to figure out what the program should be doing while its at one end holding that limit switch in a high state. I can't write the switch low while its being held pressed high by the egg turner... my plan is to use Arduino nano, relays, and micro limit switches that can be wire either normally open or normally closed. anyone know how this can be done? Total noob here so I apologize in advance if this is actually simple , I've been reading on limit switches and egg turner programming and a lot of ppl just use timers but its not very precise... they eventually go out of sync and don't rotate perfectly 45 degrees to one side then 45 to the other side. plz help! this is one challenge that is kicking my behind. I swear i'm laying in bed trying to figure this out and my wife thinks i'm thinking of other women lol Here's a few pictures and I'm holding the limit switch where I think I might put it. Maybe one on both sides if I need too.

it's still using delay(1000) which blocks the rest of the program, I'm trying to figure out if there's a way I can use a timer millis() to acheive the same result as delay(1000), and Delay with out the delay() command. using a timer for example; if (millis() - prevMillis >= timer && limitSwitch == HIGH) { stop for an hour } then resume the motor and ignore the switch is still held high

I can't find a post I made that comes at this from a certain angel. But read this one and maybe more on the thread: [image] Multiple state machines General Guidance @bagpiperdave - I've only noticed for sure now that you are using a timer library. I have nothing against libraries, but in this case it would be good if you set aside some time to learn how you might do without it, even if you continue to use it. This is the essence of the library: // a global object (or static local) is the timer elapsedMillis timeElapsed; // then, wherever in your code // check the timer object if (timeElapsed > interval) { // here be stuff that executes every int… and here, same same: [image] Trying to get millis to work with button General Guidance OK. This gets execute once when the button becomes pressed: Serial.println("ON"); lcd.setCursor(0, 2); lcd.print(" ON "); and this gets execute once when the button is released.: Serial.println("Off"); lcd.setCursor(0, 2); lcd.print(" OFF "); If I understand, you could turn on the LED when you print ON, and at the same time start a timer. Recall or learn that starting a timer in this context is simply noting the time. Here we a… After or while… you have look at, code, play with and read about "blink without delay" until you feel that Aha! thing. a7

[image] datfreak: I'm trying to figure out if there's a way I can use a timer millis() to acheive the same result as delay(1000), and Delay with out the delay() command. Using a timer to achieve the same result as the delay command isn't quite the right way to think of it. Certainly you can watch a timer to duplicate the functionality of delay(1000) by watching millis() tick for 1000 milliseconds before moving on to the next step. But that just shifs the monopolization of the processor's attention from inside delay() to inside the watching loop. The key benefit of the if (millis() - prevMillis >= timer ) {something;} trick over the while (millis() - prevMillis <= timer) {stop for an hour;} loop equivalent to delay(timer) is that instead of focusing on watching the clock as hard and as fast as you can, you've turned it into a quick check of the time so that you can pass the attention on to do other things. If you don't have any other things to do, there isn't any value in the added complexity. If you do have any other things to do, the added complexity of writing the "if(it is time to doActionX){doActionX;} logic is one of the least complex ways to handle it. If you were watching one kid do their hour's worth of homework, you could certainly stand over their shoulder and watch closely for an hour. But if you have 30 kids to watch, it's best to rethink it as a checklist: peek at each kid in turn to see if they are struggling, intervening as needed, and skipping to the next kid if not. The if(millis() - kidOneLastCheckMs > kidCheckInterval && ClassIsInSession){ checkKidOne(); kidOneLastCheckMs = millis()} is one way of turning the single child continuous focus into a checklist item that could work for 30 kids. With multiple, independent egg turners you only need a couple actions: stopEggTurnerWhenItHitsItsLimitSwitch(x), and startMovingEggTurnerAfterItRestedForAnHour(x). If you had 1000 egg turners, you could turn it into a checklist of 2000 of those tasks: for each eggturner x, if eggturner(x) is moving, check if it hit the limit switch and if so, stop it an switch it to rest mode. Or if it is in rest mode, start it moving towards its limit switch. Data-wise, you would need only keep track of whether it is moving or not, and when it started resting. Or oops--since it takes some time to move on or off of the limit switch, there's an extra complication: you'd also need to keep track of whether it is trying to move off of the limit switch or not. Data-wise in C++, plus some constants to say which pins are the associated limit switches and motor-enabling pins. You could do that with: struct EggTurners { const int MotorPin; const int LimitPin; int lastLimitState; // for edge detection on the limit switch bool isMoving; // state variable uint32_t restStartMillis; // timing state variable }; EggTurners eggTurners[] = { {2, A0}, {3, A1}, {4, A2}, {5, A3}, }; const int NumTurners = sizeof(eggTurners) / sizeof(eggTurners[0]); and do the work with something like these somewhat untested snippets: void setupEggTurners() { for (int ii = 0; ii < NumTurners ; ++ii) { pinMode(eggTurners[ii].MotorPin, OUTPUT); pinMode(eggTurners[ii].LimitPin, INPUT_PULLUP); digitalWrite(eggTurners[ii].MotorPin, HIGH); eggTurners[ii].isMoving = true; eggTurners[ii].lastLimitState = digitalRead(eggTurners[ii].LimitPin); } } void handleEggTurners() { for (int ii = 0; ii < NumTurners ; ++ii) { if (eggTurners[ii].isMoving) { int limitState = digitalRead(eggTurners[ii].LimitPin); if (limitState != eggTurners[ii].lastLimitState && limitState == LIMITING) { // triggered a limit switch while moving // stop moving and start resting Serial.print(ii); Serial.print("Limit "); digitalWrite(eggTurners[ii].MotorPin, LOW); eggTurners[ii].restStartMillis = millis(); eggTurners[ii].isMoving = false; } eggTurners[ii].lastLimitState = limitState; } else { if ( millis() - eggTurners[ii].restStartMillis > PauseTime ) { // rested long enough // stop resting and start moving Serial.print(ii); Serial.print("Move "); eggTurners[ii].isMoving = true; digitalWrite(eggTurners[ii].MotorPin, HIGH); } } } } These wrap the specific actions of "starting the motor" or "starting the rest" inside conditionals that act like a checklist on when to start or stop the several motors, keeping track of the the data needed to make the decisions (state data) in the array of structs. There are multiple good ways to do it, but the biggest trick for being able to do several things at the same time (e.g., run and pause multiple motors while monitoring their limits switches) is dumping delay() and sequential programming, and acting quickly on events. When the code is full of delay(xxx), or while(){...} its a sign that it wasn't written to handle walking and chewing gum at the same time. So don't try to "to acheive the same result as delay(1000), and Delay with out the delay()"

that looks like some hardcore coding, that's above my head at the moment lol, i don't even know how to get this code working. maybe i should look at using a timer and a limitswitch to calibrate every now and then.

Sorry. I was trying to point out an analogy to a checklist for periodically checking different things to code to do so. It is still a bit unclear what you want. Do you want one or two limit switches? One or more than one egg turners? I think that with just one egg turner with one limit switch, and delay() you should be able to keep in sync. You'd measure how much time it takes to go from the limit switch to the opposite side, then hard code that time into a the program, and use delay(). Can you make the Arduino built-in Blink example do what you want? E.g: // built from https://www.arduino.cc/en/Tutorial/BuiltInExamples/Blink const int LIMIT_PIN = 2; const int LIMIT_TRIGGERED_LEVEL = LOW; const unsigned long NinetyDegreesWorthOfMicroseconds = 600000; const unsigned long HoursWorthOfMilliseconds = 3600000; // the setup function runs once when you press reset or power the board void setup() { // initialize digital pin LED_BUILTIN as an output. pinMode(LED_BUILTIN, OUTPUT); pinMode(LIMIT_PIN,INPUT_PULLUP; } // the loop function runs over and over again forever void loop() { digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level) while(digitalRead(LIMIT_PIN) != LIMIT_TRIGGERED_LEVEL){ ; // keep running } digitalWrite(LED_BUILTIN, LOW); // turn the LED off by making the voltage LOW delay(HoursWorthOfMilliseconds); // wait for a hour digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level) delay(NinetyDegreesWorthOfMicroseconds); // wait for digitalWrite(LED_BUILTIN, LOW); // turn the LED off by making the voltage LOW delay(HoursWorthOfMilliseconds); // wait for a hour } If you need to do things like run multiple egg turners, or do anything else but completely focus on watching the limit switch, or letting delay() completely focus on watching the clock , you'll need to learn how to do Several Things at the Same Time: [image] Wokwi Simulations for Arduino Built-In Examples General Guidance Doing several things at the same time: Demonstration code for several things at the same time by @Robin2-- An example running a couple blinking LEDS, a button and two servos, all independently. (Live Simulation) (Off-site: Adafruit: Multiasking the Arduino Part 1, Part 2) @nickgammon on Blinking multiple things Blink Two LEDs Simulation Blink Several LEDs with Class Simulation Fade Several LEDs with Class Simulation Combining multiple non-blocking codes The last link is a thread combining …

it doesn't matter if i use 1 limit switch and a timer or 2 limit switches, as long as it does what I need it to do I'll be happy. I have 8 egg turners like the above picture to control. So delay() won't work. I Did try blending the blinkwithout delay and the statechangedetection sketch but still no luck.

Programming limit switch?

Projects Programming

alto777 March 29, 2025, 8:42pm 69

I can't find a post I made that comes at this from a certain angel.

But read this one and maybe more on the thread:

and here, same same:

After or while… you have look at, code, play with and read about "blink without delay" until you feel that Aha! thing.

Topic		Replies	Views
Motor reverse ideas General Guidance	96	1538	August 29, 2026
Motor not responding General Guidance	53	1037	August 25, 2026
Control of the gear motor at a given speed General Guidance	94	5093	April 9, 2023
Stepper motor, tmc 2209, 6 switches (speed and full rotations) Programming	151	1711	March 23, 2026
Limit Switch Timeout help Programming	14	1512	June 17, 2022

Programming limit switch?

Related topics