Arduino tutorials for beginner and intermediate Makers

What is the difference between unipolar and bipolar stepper motors? It's in the coils.

Bipolar stepper motors are generally able to produce more torque than unipolar stepper motors, and are more efficient.

However, they are more complicated to drive (="operate"). The main difference between the two types of stepper motors has to do with the way that the wire winding is constructed. 

DC motors draw currents that can be beyond the ability of the Arduino to supply. Transistors can be used as very simple at fast on/off switches and are an excellent option for designing simple motor controllers.

Any DC motor can be driven with PWM simple signals that can be generated by the Arduino Uno and virtually any other microcontroller. Just like you can control the intensity of an LED, you can use PWM to control the rotational speed of a DC motor. 

Stepper motors move in steps. The width of a step is determined by the physical characteristics of the motor's rotor. With a clever technique called "microstepping", your stepper motor can double, quintuple or even octuple its precision. Read this article to also learn new words.

Stepper motors are capable of moving their rotor on specific positions along a 360° arc. The exact positions are defined by the positions of the toothed electromagnets positioned on the central rotor.

Direct current motors represent the easiest way to add movement to your projects. A direct current or DC motor can be a very cost effective and flexible solution for all sorts of projects: robots, cars, boats, toy helicopters, home automation, and many more.

In this article, you will learn how to use a DC motor through a series of three projects.

To implement the projects, you will need two 5V DC motors and a L289N motor driver module.

The L298N motor controller is a low cost and simple way to control two DC motors at the same time. It works well with the Arduino, and once you learn how to use it, you will be able to apply it on a wide range of DC motors.

In this article you will learn how to control two 5V DC motors with your Arduino.

To enable the Arduino to safely control the motors, you will use the L298N motor controller module.

In this project, you will learn how to control the speed and direction of spin of the DC motor's rotor. You will use a potentiometer to provide input to the Arduino, and the map() and analogWrite() functions in your sketch to make this work.

In this experiment you will take the next step. You will learn how to control the speed and the direction of the two motors. In the role of the user interfaceyou will use a 10 kΩ potentiometer.

Let's try a variation of the Project 2 experiment: control the speed of the DC motor with an ultrasonic distance sensor. Of course, we'll use an Arduino and the L298N motor driver.

In this article, I will describe one last experiment that involves a DC motor. We will connect an ultrasonic distance sensor in the place of the potentiometer, and use that to control the rotational speed of the motors.

Servo motors are used in applications where precision movement is required, such as in robotics. It is very easy to control one or more servo motors with the Arduino. Learn how with this article.

The DC motor is a versatile, low-priced solution for providing motion to your projects. A “weakness” (or characteristic) of the plain vanilla DC motor is that when you apply voltage to its coil, it will spin as fast as its mechanics and load allows.

Well-crafted libraries allow us to improve the quality of our gadgets with very little additional effort. In this article, you will learn how to use a simple library to improve your servo motor controller sketches with minimal changes in your code.

The build in Servo library is good and very simple to use. However, there’s more we can do with the hardware than it allows us.

Learn how to calibrate and improve the reliability of the infrared motion sensor.

Learn the basic functions of the TimerOne library that makes it easy to use the Atmega328's 16-bit counter.

How do you find out the address of an I2C device that is poorly documented?

What is I2C? How many devices are supported on a bus? Is I2C supported by the Arduino Uno? How does it work?

The Arduino Uno, with its Atmega328P MCU, does not have true digital to analog conversion capability. For this, we turn to an external device, the PCF8591.

Is the temperature reading from your sensors close to being real? What is real temperature? What are some of the main considerations?

The MCP9808 is a very accurate temperature sensor for your Arduino. It offers user-selected resolutions, programmable alerts, I2C connectivity, and works with 5V and 3.3V Arduinos.

Modern gadgets are mobile and can be "aware" of their motion with the use of motions sensors. There are integrated devices that combine (fuse) multiple motion sensors to produce accurate and reliable motion information for your gadget.

Is it OK to leave unused pins "floating"? The answer is in the datasheet of your favorite microcontroller. Let's decipher it here.

What happens if you write a PWM value that is larger than the maximum value that the Arduino's analogWrite() function can accommodate? This is an interesting case of "buffer overflow".

The "baud" rate is a unit used to describe the speed of serial communications between two electronic devices. The exact meaning of this unit is often clout in confusion. What exactly is "baud"?

We use the println() function to print a string to the serial monitor. The same function is overloaded with a second parameter that allows us to designate the type of data we want to display.

The short answer is, it does not matter.

But there's a catch.

The Arduino language contains several easily recognizable variables, like "bool", "byte", "int" and "char". But, below the surface, the Arduino language is really a subset of the C language that works on microcontrollers. With it, you will find many specialized data types designed to ensure compatibility across devices that don't always treat a byte the same way.

In embedded devices, like the Arduino, RAM is limited. However, there are a few simple methods you can use to reduce the memory footprint of your sketches so that they will fit in the available memory space. The F() macro is one such method.

When the Serial object in your sketch and the Arduino IDE serial monitor are set to the same speed, you would expect that clear, readable text would appear on your screen.
Sometimes it doesn't. What's going on? is it a glitch? what can explain the gibberish that appears?

The map() function makes it easy to convert numbers from one range to another. Here's a simple example of its usage.

A student asked me: What is the meaning of a “weird” keyword used in a constructor? It was the keyword “POSITIVE” in one of the constructors from the LiquidCrystal_I2C class.

Interrupt service routines (ISR) must be as small as possible. If your sketch has to do time-consuming work after an interrupt event, you can use volatile variables to capture data and process it outside of the ISR.

Microcontrollers have scarce resources. Perhaps their most important resource is compute time, followed by RAM and Flash memories. Therefore, we should not waste our MCU's time. But when you use delay(), you actually waste time.

The Arduino contains a 32-bit register that is actually a counter. It counts the number of milliseconds elapsed since the time you powered-up the Arduino. We use this counter to count time. But, what happens when the counter reaches its maximum value? Let's figure it out with the help of an example.

An interrupt service routine (ISR) looks like a regular function. It can hold any code you want, and it will work as it would in any other function.
But, the ISR is not a regular function, and you should treat it as special.

As you become more skilled in programming, you will begin to notice that style matters almost as much as functionality. An element of style in programming is the ability to shrink code without altering its functionality. This results in smaller, more concise programs.

If you have an Arduino application that must parse an HTTP response, it helps to understand the difference between the two most common special characters: line feed and carriage return. Once you understand this, you will be able to reduce the complexity of your parser by half.

The topic of memory pointers in C and C++ is a known cause of intense headaches for many of us. It is the one topic that will most often scare people away from C/C++ and into "higher level" languages like Python and Ruby. But, with a bit of patience, you can understand it.

The key to multitasking is efficient and clever programming. Simple multitasking on the Arduino is possible.

It is a common practice to use arrays to store chars, ints, or double values.
But arrays can also store booleans. Here's how.

The Arduino Due and Arduino Zero are far more powerful than the Arduino Uno. They use microcontrollers based on 32-bit ARM technology. With the help of the Scheduler library, you can use them as potent multitasking machines.

Programming a microcontroller entails much more bit-level manipulation than what is common in general computer programming. Bitwise operators like "<<", ">>" and "|" are essential. Let's look at two of the most common bitwise operators, bitshift right and bitwise OR.

The C language contains special keywords that modify the way a variable behaves. One of them is the keyword "static". The way it works is not obvious, so I have created a series of experiments to help you understand.

Variables can be modified at different parts of a program. Often, it is not possible to predict when a particular variable may be accessed for a read or write operation. This is particularly true when a variable is tied to an interrupt service routine. So, how do we ensure that a variable always contains a correct value? This is where the volatile modifier comes in.

Your Arduino's microcontroller contains special software, the bootloader, which makes it very easy to upload new sketches. It is possible to replace the default bootloader with a more efficient variation and hence implement a software upgrade to give your Arduino more space for your sketches and faster uploads.

A real-time operating system is optimized so that processing is completed within tight time bounds, and execution is consistent and predictable. It is the preferred operating system for critical applications. And a version of it works on the Arduino Uno.