Hi
I have a stepper that runs when a toggle button is pressed. On the LCD I have a countdown using millis() subtracting seconds from the total runtime.
The problem is that every time the LCD updates (every second) the motor has an interrupt, it stutters every millis interval().
How do I update the LCD every second without interrupting the stepper?
Please post your code as decribed in the how to get the best from the forum post.
A wiring diagram would probably be helpful, too.
I am using nema 34 stepper motor 12 Nm torque with 5.2A and Stepper motor driver 2D68MH, LCD Display 20*4 with I2C module, 4 Push buttons, 2 limiting switches,
Here is below Arduino code:
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#define BUZZER_PIN 7 // Define the buzzer pin
#define BUZZ_DURATION_SHORT 65 // Define duration for short buzz
#define BUZZ_DURATION_LONG 2000 // Define duration for long buzz
#define BUZZ_DURATION_INITIAL 1500 // Define duration for initial buzz
#define BUZZ_DURATION_COMPLETE 3000 // Define duration for complete buzz
#define DEBOUNCE_DELAY 200
LiquidCrystal_I2C lcd(0x27, 20, 4); // Set the LCD address to 0x27 for a 20 chars and 4 line display
const int clockwiseLimitPin = 6; // Change to your clockwise limit switch pin
const int counterclockwiseLimitPin = 5; // Change to your counterclockwise limit switch pin
bool clockwiseLimitReached = true;
bool counterclockwiseLimitReached = false;
const int modeButtonPin = 8;
const int increaseButtonPin = 10;
const int decreaseButtonPin = 9;
const int toggleButtonPin = 11;
unsigned long previousMillis = 0;
const long interval = 1000; // Update interval (1 second)
enum TimerState { HH, MM, SECONDS_STATE, FLEX_DELAY, EXT_DELAY, COUNTDOWN, PAUSED }; // Changed SS to SECONDS_STATE
TimerState currentState = HH;
int hours = 0;
int minutes = 0;
int seconds = 0;
int flexDelay = 0; // Flexion delay in seconds
int extDelay = 0; // Extension delay in seconds
bool startTimer = false;
bool togglePressed = false; // Added a togglePressed variable to track button state
bool displayNeedsUpdate = true; // Flag to track if display needs update
bool cursorOn = false; // Flag to track cursor position
int cursorPosition = 0; // Track cursor position (0 for HH, 1 for MM, 2 for SECONDS_STATE, 3 for FLEX_DELAY, 4 for EXT_DELAY)
// Stepper motor pins
const int dirPin = 3;
const int stepPin = 2;
const int enablePin = 4;
void setup() {
lcd.init();
lcd.backlight();
pinMode(modeButtonPin, INPUT_PULLUP);
pinMode(increaseButtonPin, INPUT_PULLUP);
pinMode(decreaseButtonPin, INPUT_PULLUP);
pinMode(toggleButtonPin, INPUT_PULLUP);
pinMode(BUZZER_PIN, OUTPUT); // Initialize buzzer pin as output
pinMode(dirPin, OUTPUT);
pinMode(stepPin, OUTPUT);
pinMode(enablePin, OUTPUT);
buzz(BUZZ_DURATION_INITIAL);
// Other setup code...
pinMode(clockwiseLimitPin, INPUT_PULLUP);
pinMode(counterclockwiseLimitPin, INPUT_PULLUP);
}
bool countdownEnded = false; // Flag to track if the countdown has ended
void loop() {
unsigned long currentMillis = millis();
if (currentMillis - previousMillis >= interval) {
previousMillis = currentMillis;
if (startTimer && currentState == COUNTDOWN) {
if (hours == 0 && minutes == 0 && seconds == 0) {
startTimer = false;
currentState = HH;
displayNeedsUpdate = true;
countdownEnded = true; // Set the flag to true when countdown ends
} else {
updateTimer();
displayNeedsUpdate = true;
}
}
}
// Perform stepper motor steps if the timer is running
if (startTimer && currentState == COUNTDOWN) {
motorStep(2000); // Adjust the step count as needed
}
if (digitalRead(modeButtonPin) == LOW) {
debounce();
switchMode();
displayNeedsUpdate = true;
buzz(BUZZ_DURATION_SHORT); // Short buzz when mode button is pressed
}
if (digitalRead(increaseButtonPin) == LOW) {
debounce();
increaseValue();
displayNeedsUpdate = true;
}
if (digitalRead(decreaseButtonPin) == LOW) {
debounce();
decreaseValue();
displayNeedsUpdate = true;
}
if (digitalRead(toggleButtonPin) == LOW && !togglePressed) {
debounce();
togglePressed = true;
toggleCountdown();
displayNeedsUpdate = true;
} else if (digitalRead(toggleButtonPin) == HIGH && togglePressed) {
debounce();
togglePressed = false;
}
// Check if limit switches are triggered
if (digitalRead(clockwiseLimitPin) == LOW) {
stopMotorAndApplyDelay(extDelay); // Apply EXT delay
reverseMotorDirection(clockwiseLimitPin);
delay(100); // Add a small delay for stability
}
if (digitalRead(counterclockwiseLimitPin) == LOW) {
stopMotorAndApplyDelay(flexDelay); // Apply FLX delay
reverseMotorDirection(counterclockwiseLimitPin);
delay(100); // Add a small delay for stability
}
if (displayNeedsUpdate) {
if (countdownEnded) {
lcd.setCursor(0, 0);
lcd.print(" CPM stopped ");
} else {
displayTimer();
}
displayNeedsUpdate = false;
}
}
void stopMotorAndApplyDelay(int delayTime) {
digitalWrite(enablePin, HIGH); // Disable the motor
delay(delayTime * 1000); // Apply delay in milliseconds
}
void reverseMotorDirection(int limitSwitchPin) {
// Determine which limit switch has been triggered and reverse motor direction accordingly
if (limitSwitchPin == clockwiseLimitPin) {
// Reverse motor direction for clockwise limit switch
digitalWrite(enablePin, LOW); // Enable the motor
digitalWrite(dirPin, LOW); // Set the direction of rotation
} else if (limitSwitchPin == counterclockwiseLimitPin) {
// Reverse motor direction for counterclockwise limit switch
digitalWrite(enablePin, LOW); // Enable the motor
digitalWrite(dirPin, HIGH); // Set the direction of rotation
}
}
void debounce() {
delay(DEBOUNCE_DELAY);
}
void switchMode() {
cursorOn = true; // Turn on cursor
cursorPosition = (cursorPosition + 1) % 5; // Cycle through cursor positions (0, 1, 2, 3, 4)
currentState = static_cast<TimerState>(cursorPosition); // Update timer state based on cursor position
}
void increaseValue() {
switch (currentState) {
case HH:
hours = (hours + 1) % 24;
break;
case MM:
minutes = (minutes + 1) % 60;
break;
case SECONDS_STATE:
seconds = (seconds + 1) % 60;
break;
case FLEX_DELAY:
flexDelay = (flexDelay + 1) % 11; // Flex delay from 0 to 10 seconds
break;
case EXT_DELAY:
extDelay = (extDelay + 1) % 11; // Extension delay from 0 to 10 seconds
break;
default:
break;
}
}
void decreaseValue() {
switch (currentState) {
case HH:
hours = (hours - 1 + 24) % 24;
break;
case MM:
minutes = (minutes - 1 + 60) % 60;
break;
case SECONDS_STATE:
seconds = (seconds - 1 + 60) % 60;
break;
case FLEX_DELAY:
flexDelay = (flexDelay - 1 + 11) % 11; // Flex delay from 0 to 10 seconds
break;
case EXT_DELAY:
extDelay = (extDelay - 1 + 11) % 11; // Extension delay from 0 to 10 seconds
break;
default:
break;
}
}
void toggleCountdown() {
if (currentState == COUNTDOWN) {
startTimer = !startTimer; // Toggle startTimer value
if (!startTimer) {
currentState = PAUSED;
buzz(BUZZ_DURATION_LONG);
}
} else {
currentState = COUNTDOWN;
startTimer = true;
if (countdownEnded) {
countdownEnded = false; // Reset countdownEnded flag
displayNeedsUpdate = true; // Trigger display update to show the main screen
cursorOn = false; // Turn off cursor
currentState = HH; // Reset timer state to HH
hours = 0; // Reset hours
minutes = 0; // Reset minutes
seconds = 0; // Reset seconds
flexDelay = 0; // Reset flex delay
extDelay = 0; // Reset extension delay
}
}
}
void updateTimer() {
if (seconds > 0) {
seconds--;
} else {
if (minutes > 0) {
minutes--;
seconds = 59;
} else {
if (hours > 0) {
hours--;
minutes = 59;
seconds = 59;
}
}
}
}
void displayTimer() {
lcd.clear();
if (currentState == COUNTDOWN && hours == 0 && minutes == 0 && seconds == 0) {
lcd.setCursor(0, 0);
lcd.print(" CPM stopped ");
return;
}
lcd.setCursor(0, 0);
lcd.print("Timer = HH:MM:SS");
lcd.setCursor(0, 2);
lcd.print("FLX Delay = ");
lcd.print(flexDelay);
lcd.print("s"); // Add "s" after flex delay value
lcd.setCursor(0, 3);
lcd.print("EXT Delay = ");
lcd.print(extDelay);
lcd.print("s"); // Add "s" after extension delay value
lcd.setCursor(8, 1);
if (cursorOn && currentState != COUNTDOWN && currentState != PAUSED) {
switch (cursorPosition) {
case 0:
lcd.print(">");
lcd.print(hours < 10 ? "0" : "");
lcd.print(hours);
lcd.print(":");
lcd.print(minutes < 10 ? "0" : "");
lcd.print(minutes);
lcd.print(":");
lcd.print(seconds < 10 ? "0" : "");
lcd.print(seconds);
break;
case 1:
lcd.print(hours < 10 ? "0" : "");
lcd.print(hours);
lcd.print(":>");
lcd.print(minutes < 10 ? "0" : "");
lcd.print(minutes);
lcd.print(":");
lcd.print(seconds < 10 ? "0" : "");
lcd.print(seconds);
break;
case 2:
lcd.print(hours < 10 ? "0" : "");
lcd.print(hours);
lcd.print(":");
lcd.print(minutes < 10 ? "0" : "");
lcd.print(minutes);
lcd.print(":>");
lcd.print(seconds < 10 ? "0" : "");
lcd.print(seconds);
break;
case 3:
lcd.print(hours < 10 ? "0" : "");
lcd.print(hours);
lcd.print(":");
lcd.print(minutes < 10 ? "0" : "");
lcd.print(minutes);
lcd.print(":");
lcd.print(seconds < 10 ? "0" : "");
lcd.print(seconds);
lcd.setCursor(12, 2); // Set cursor position for flex delay
lcd.print(">");
lcd.print(flexDelay);
lcd.print("s"); // Add "s" after flex delay value
break;
case 4:
lcd.print(hours < 10 ? "0" : "");
lcd.print(hours);
lcd.print(":");
lcd.print(minutes < 10 ? "0" : "");
lcd.print(minutes);
lcd.print(":");
lcd.print(seconds < 10 ? "0" : "");
lcd.print(seconds);
lcd.setCursor(12, 3); // Set cursor position for extension delay
lcd.print(">");
lcd.print(extDelay);
lcd.print("s"); // Add "s" after extension delay value
break;
}
} else {
lcd.print(hours < 10 ? "0" : "");
lcd.print(hours);
lcd.print(":");
lcd.print(minutes < 10 ? "0" : "");
lcd.print(minutes);
lcd.print(":");
lcd.print(seconds < 10 ? "0" : "");
lcd.print(seconds);
}
lcd.setCursor(0, 0);
if (currentState == COUNTDOWN) {
lcd.print(" CPM started ");
} else if (currentState == PAUSED) {
lcd.print(" CPM paused ");
}
}
void buzz(int duration) {
digitalWrite(BUZZER_PIN, HIGH); // Turn on buzzer
delay(duration); // Wait for the specified duration
digitalWrite(BUZZER_PIN, LOW); // Turn off buzzer
}
// Function to control stepper motor
void motorStep( int steps){
for(int i = 0; i < steps; i++) {
digitalWrite(stepPin,HIGH);
delayMicroseconds(200);
digitalWrite(stepPin,LOW);
delayMicroseconds(200);
}
}
Can anyone help me instantly to solve this issue?
Updating the LCD takes time, so your
cannot be called continously. ( Apart from that it is a blocking call )
Your debouncing is a little bit weired too 
Which board are you using? If it is supported by the MobaTools library you could use it for step creating and switch debouncing. Tis library creates the step via timer ISR. So steps are even created while the LCD is updated.
I think your sketch needs to be changed significantly to solve your problem.
I am using arduino uno and breadboard
So you can give MobaTools a try. I'm pretty shure it can solve your problem
Yes I tried mobatools but code could not execute
I am facing this issue,
exit status 1
Compilation error: 'MobaStepper' does not name a type; did you mean 'MoToStepper'?
The compiler obviously tells you what is wrong. Did you read the documentation and have a look at the examples?
Without seeing the code, no advice is possible.
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