Stepper motor basics in Arduino - Step-by-Step Execution

Concept Flow - Stepper motor basics

Start

↓

Initialize motor pins

↓

Set motor speed

↓

Loop start

↓

Step motor one step

↓

Delay for speed control

↓

Repeat loop

This flow shows how an Arduino program controls a stepper motor by initializing pins, setting speed, and stepping the motor repeatedly.

Execution Sample

Arduino

#include <Stepper.h>
const int stepsPerRevolution = 200;
Stepper myStepper(stepsPerRevolution, 8, 9, 10, 11);

void setup() {
  myStepper.setSpeed(60);
}

void loop() {
  myStepper.step(stepsPerRevolution);
  delay(1000);
}

This code makes the stepper motor turn one full revolution at 60 RPM, then waits 1 second, and repeats.

Execution Table

Step	Action	Variable/Function	Value/Result	Notes
1	Initialize steps per revolution	stepsPerRevolution	200	Defines steps for one full turn
2	Create Stepper object	myStepper	Stepper(200, 8, 9, 10, 11)	Assigns pins and steps
3	Setup: set speed	myStepper.setSpeed(60)	Speed set to 60 RPM	Motor speed configured
4	Loop start	loop()	Start loop	Begin repeating steps
5	Step motor	myStepper.step(200)	Motor turns 1 revolution	Motor moves 200 steps
6	Delay	delay(1000)	Wait 1000 ms	Pause before next turn
7	Loop repeats	loop()	Repeat steps 5-6	Continuous rotation

💡 Loop runs forever, motor keeps turning one revolution every 2 seconds

Variable Tracker

Variable/Function	Start	After Step 3	After Step 5	After Step 7 (Loop)
stepsPerRevolution	200	200	200	200
myStepper speed	undefined	60 RPM	60 RPM	60 RPM
myStepper position	0 steps	0 steps	200 steps	400 steps

Key Moments - 3 Insights

Why does the motor turn exactly one full revolution?

Because we call myStepper.step(200), and 200 is the number of steps per revolution (see execution_table row 5).

What controls how fast the motor turns?

The speed is set by myStepper.setSpeed(60) in setup (execution_table row 3), which sets the motor speed to 60 RPM.

Why is there a delay after stepping the motor?

The delay(1000) pauses the program for 1 second (execution_table row 6), so the motor waits before turning again, making the motion visible.

Visual Quiz - 3 Questions

Look at the execution table, what value is assigned to stepsPerRevolution at step 1?

A 200

B 60

C 1000

D 8

💡 Hint

Check the first row of the execution_table where stepsPerRevolution is initialized.

At which step does the motor complete one full revolution?

A Step 3

B Step 5

C Step 6

D Step 7

💡 Hint

Look at the action 'Step motor' in the execution_table.

If we change setSpeed(60) to setSpeed(120), what happens to the motor speed?

A Motor speed stays the same

B Motor speed halves

C Motor speed doubles

D Motor stops

💡 Hint

Refer to the variable_tracker row for myStepper speed and execution_table row 3.

Concept Snapshot

Stepper motor basics in Arduino:
- Define steps per revolution (e.g., 200)
- Create Stepper object with pins
- Set motor speed with setSpeed(RPM)
- Use step(n) to move motor n steps
- Use delay() to control timing
- Loop to repeat motion continuously

Full Transcript

This visual execution trace shows how an Arduino program controls a stepper motor. First, it defines the number of steps per revolution as 200. Then, it creates a Stepper object with four control pins. In setup, it sets the motor speed to 60 RPM. The loop repeatedly commands the motor to step 200 steps, which equals one full revolution, then waits one second before repeating. Variables like stepsPerRevolution and motor speed remain constant, while the motor position increases by 200 steps each loop. Key moments include understanding how step count controls rotation, how speed affects turning rate, and why delay is needed to see the motion clearly. The quiz checks understanding of these steps and effects of changing speed.