How to do something after moveTo has finished its move in proper way?

[Stipena]

Hi! I'm trying to control two steppers via serial. How do I Serial.print something after moveTo has finished its move? For now I tried While(isRunning()) loop with nothing in it, which works but I loose ability to stop stepper or give it new command to move to other position. Like example if I write command "swing 50" stepper starts moving and if in middle of its movement I give it "swing 10" it doesn't stop nor it moves to new position. Only after it finishes first move it Serial.prints me a feedback and starts second movement. In future I will also need function to move stepper1 and after it finished move stepper2. Without that function I'm risking to break vertical blinds mechanism or even worse to break a window. Even tho I'm playing with AVR chips and arduino for 17 years I'm still very novice and things is hard to understand. So I would like to get some help.

#include "FastAccelStepper.h"
#include "AVRStepperPins.h" // Only required for AVR controllers

#define stepPinStepper1A 9  /* OC1A */
#define stepPinStepper1B 10 /* OC1B */
#define DIR_PIN_1 7   // Direction pin for stepper 1. Grey wire.
#define DIR_PIN_2 8   // Direction pin for stepper 2. Purple wire.
#define LIMIT_SWITCH_PIN_1 4  // Limit switch pin for stepper 1. Yellow wire.
#define LIMIT_SWITCH_PIN_2 2  // Limit switch pin for stepper 2. Orange wire.
#define SWITCH_PIN 12

FastAccelStepperEngine engine = FastAccelStepperEngine();
FastAccelStepper *stepper1 = NULL;
FastAccelStepper *stepper2 = NULL;

const int Microstepping_1 = 200;
const int Microstepping_2 = 200;

int speed_1 = 10;
int door_speed_1 = 20;
int speed_2 = 5;
int door_speed_2 = 10;
int acceleration_1 = 1000;
int door_acceleration_1 = 5000;
int acceleration_2 = 1000;
int door_acceleration_2 = 5000;
int open_1 = 20000;
long open_2 = 2000;
int door_1 = 2000;
int middle = 1000;
int percentage_1 = 50;
long percentage_2;
long swing;

void setup() {
  Serial.begin(115200);
  pinMode(LIMIT_SWITCH_PIN_1, INPUT_PULLUP);  // Set limit switch pin as input with pull-up resistor
  pinMode(LIMIT_SWITCH_PIN_2, INPUT_PULLUP);  // Set limit switch pin as input with pull-up resistor
  pinMode(SWITCH_PIN, INPUT_PULLUP);          // Set switch pin as input with pull-up resistor

  // Initialize the engine
  engine.init();

  // Create the stepper 1 object
  stepper1 = engine.stepperConnectToPin(stepPinStepper1A);
  if (stepper1) {
    stepper1->setDirectionPin(DIR_PIN_1);
    stepper1->setAutoEnable(true);
  }

  // Create the stepper 2 object
  stepper2 = engine.stepperConnectToPin(stepPinStepper1B);
  if (stepper2) {
    stepper2->setDirectionPin(DIR_PIN_2);
    stepper2->setAutoEnable(true);
  }

  homeStepper1();  // Homing procedure for stepper 1
  homeStepper2();  // Homing procedure for stepper 2
}

void loop() {
  unsigned long currentTime = millis();

  if (Serial.available()) {
    String input = Serial.readStringUntil('\n');
    processCommand(input);
  }

}

void processCommand(String input) {
  input.trim();
//Variable commands
  if (input.startsWith("m_1 ")) {
    long position_1 = input.substring(4).toInt();
    Serial.println("u_1 Moving");
    stepper1->setSpeedInHz(rpmToStepsPerSecond(speed_1, Microstepping_1));
    stepper1->setAcceleration(acceleration_1);
    stepper1->moveTo(position_1);
    Serial.print("m_1 ");
    Serial.println(position_1);
  } else if (input.startsWith("m_2 ")) {
    long position_2 = input.substring(4).toInt();
    Serial.println("u_2 Moving");
    stepper1->setSpeedInHz(rpmToStepsPerSecond(speed_2, Microstepping_2));
    stepper1->setAcceleration(acceleration_2);
    stepper1->moveTo(position_2);
    Serial.print("m_2 ");
    Serial.println(position_2);
  } else if (input.startsWith("s_1 ")) {
    speed_1 = input.substring(4).toInt();
    Serial.print("u_1 Speed ");
    Serial.print(speed_1);
    Serial.println("rpm");
  } else if (input.startsWith("d_s_1 ")) {
    door_speed_1 = input.substring(6).toInt();
    Serial.print("u_1 Door speed ");
    Serial.print(door_speed_1);
    Serial.println("rpm");
  } else if (input.startsWith("s_2 ")) {
    speed_2 = input.substring(4).toInt();
    Serial.print("u_2 Speed ");
    Serial.print(speed_2);
    Serial.println("rpm");
  } else if (input.startsWith("d_s_2 ")) {
    door_speed_2 = input.substring(6).toInt();
    Serial.print("u_2 Door speed ");
    Serial.print(door_speed_2);
    Serial.println("rpm");
  } else if (input.startsWith("a_1 ")) {
    acceleration_1 = input.substring(4).toInt();
    Serial.print("u_1 Acceleration ");
    Serial.println(acceleration_1);
  } else if (input.startsWith("d_a_1 ")) {
    door_acceleration_1 = input.substring(6).toInt();
    Serial.print("u_1 Door acceleration ");
    Serial.println(door_acceleration_1);
  } else if (input.startsWith("a_2 ")) {
    acceleration_2 = input.substring(4).toInt();
    Serial.print("u_2 Acceleration ");
    Serial.println(acceleration_2);
  } else if (input.startsWith("d_a_2 ")) {
    door_acceleration_2 = input.substring(6).toInt();
    Serial.print("u_2 Door acceleration ");
    Serial.println(door_acceleration_2);
  } else if (input.equals("set_o_1")) {
    open_1 = stepper1->getCurrentPosition();
    door_1 = (percentage_1 * open_1) / 100;
  } else if (input.equals("set_o_2")) {
    open_2 = stepper2->getCurrentPosition();
    middle = open_2 / 2;
  } else if (input.startsWith("set_d ")) {
    percentage_1 = input.substring(6).toInt();
    door_1 = (percentage_1 * open_1) / 100;
  }
//Moving commands
  else if (input.startsWith("swing ")) {
    if (stepper1->getCurrentPosition() == 0) {
      percentage_2 = input.substring(6).toInt();
      swing = (percentage_2 * open_2) / 100;
      stepper2->setSpeedInHz(rpmToStepsPerSecond(door_speed_2, Microstepping_2));
      stepper2->setAcceleration(door_acceleration_2);
      stepper2->moveTo(swing);
      while (!stepper2->isRunning()) {
        //just waiting to finish moving
      }
      Serial.print("u_2 ");
      Serial.print(percentage_2);
      Serial.print("%, ");
      Serial.print("target: ");
      Serial.print(swing);
      Serial.print(", current: ");
      Serial.println(stepper2->getCurrentPosition());
    }
  }
}

int rpmToStepsPerSecond(int rpm, int microsteps) {
  // Convert RPM to steps per second based on the microstepping
  return (rpm * microsteps) / 60;
}

void homeStepper1() {
  Serial.println("status1Homing motor 1...");
  stepper1->setSpeedInHz(rpmToStepsPerSecond(5, Microstepping_1));  // Set homing speed
  stepper1->setAcceleration(50000);                                    // Set maximum acceleration for homing
  stepper1->runBackward();                                              // Start moving backward (reverse homing direction)

  while (digitalRead(LIMIT_SWITCH_PIN_1) == HIGH) {   // Move until the limit switch is triggered
    delay(1);
  }

  stepper1->forceStopAndNewPosition(0);  // Stop and set the current position as zero
  Serial.println("status1Homing motor 1 complete");
}

void homeStepper2() {
  Serial.println("status2Homing motor 2...");
  stepper2->setSpeedInHz(rpmToStepsPerSecond(5, Microstepping_2));  // Set homing speed
  stepper2->setAcceleration(50000);                                    // Set maximum acceleration for homing
  stepper2->runBackward();                                              // Start moving backward (reverse homing direction)

  while (digitalRead(LIMIT_SWITCH_PIN_2) == HIGH) {   // Move until the limit switch is triggered
    delay(1);
  }

  stepper2->forceStopAndNewPosition(0);  // Stop and set the current position as zero
  Serial.println("status2Homing motor 2 complete");
}

[gin66]

FastAccelStepper is built to support non-blocking operations, even so blocking mode can be used, too: the move operations support a second parameter called block, which avoids the while-loop for isRunning() on application side.

Non-blocking mode is fantastic, but way more complex to develop for. If non-blocking mode is used, this means, that more or less the whole loop() should be non-blocking. And this starts already with reading serial data. In the supplied code, blocking serial reads are used. Imagine, a received serial command requests stepper1 to run to position 1000. After the moveTo-command, the loop is starting again and is blocked waiting for serial input. If the motor is stopping during this wait, it is not possible to print something out.

So you need to start with polling bytes from serial, assembling the bytes into a buffer and on newline evaluate the buffer. If no byte has been received, the code can proceed with checking the motor state. Eventually print out, that motor has stopped, or the home position has been reached and motor needs to stop immediately….

You may check, the StepperDemo in the examples-directory, which gives some insights, even though it may be difficult to read due to its complexity.

[Stipena]

Forgot to mention that I will use ESP32 for project, now I use Arduino Uno just because Wokwi stopped working with Fastaccelstepper library due to recent esp32 boards update to version 3. I will not use WiFi for it, so maybe it is possible to offload serial to different core just not to block loop?
Cleaned code a bit just for example purposes. Is this approach is good enough? Should I do the same with "lean" command to move stepper2 when stepper1 finishes? Using blocking movements isn't an option. Of course there will be a lot more commands where I will want sequential steppers movements.

[Stipena]

Looked to that StepperDemo before and frankly can't understand it. The code I wrote is practically chatgpt-4o written, I just made few tweeks. I have full code from chatgpt with sequential steppers moves made, but that part of code is buggy and sometimes causes unwanted sequence of moves. So I thought I will rewrite code myself, but it looks like I'm not going anywhere with my level of skills.