Which Arduino pin for vex encoder signal

 The encoder signal is a 2-wire serial interface. The Arduino uses an interrupt pin for the encoder. Which one you need to use depends on your Arduino encoder. With Arduino UNO or Nano models, you will use digital pin 2 (D2). Arduino Mega and Leonardo use digital pin 3 (D3). You can change the interrupt line by modifying the ‘encoder_pin’ variable in the code.

How to create a menu using rotary encoder in Arduino

This menu has four functions, forward, reverse, left, and right.

The encoder is a rotary device that you can rotate clockwise or counterclockwise. The rotary encoder is a mechanism to encode the input value as the number of steps that it makes a full revolution. The mechanical mechanism consists of three-position sensors and an electronic encoder. Each of these parts has four components. The ‘position sensor’ has a set of coils (cathode, anode, shield). It makes the sensor react when an electric current passes through it. The entire mechanism’s construction depends on a single axis parallel-axis rotary shaft.

Now let’s start learning about rotary encoder pinout in Arduino IDE.

Select Tools > Board and select the board you want to use.

Next, go to Tools> Port and select the port there too.

After this, you will get a new project (File>New):

In this case, we choose Arduino UNO R3:

This code works with an Arduino UNO R3 with an encoder that outputs 8 bits of data.

The code is simple and easy to read. What you have to do is change the values at the start of your program, which are:

encoder_pin = 2
encoder_show = 1
encoder_mode = 0
shift = 0
goToStep=0
step=0
Types of Rotary Encoders
There are a few types of rotary encoders that you can purchase. So, it is essential to know the difference between them.

1. Mechanical Absolute Rotary Encoders
A mechanical absolute rotary encoder measures the rotation of the encoder shaft in a fixed circular path. Each click represents one revolution. An internal stop will not allow the shaft to rotate any further. We use this type of encoder in applications that require a limited number of positions, such as turning on a set of lights or operating an elevator. These encoders are cheaper but are more limited in terms of capabilities.

It is a common low-cost option for low-volume products.

2. Optical Absolute Rotary Encoders
Optical absolute encoders measure rotation by emitting a light beam. It also measures the reflection with a photoelectric sensor.

This type of encoder has a very long life span, is easy to implement, and is more durable than its relative.

They are the right choice for applications that need to measure the position of their motor under harsh conditions. These types tend to have higher price tags but can be worth it if they will be in continuous use.

You can construct them with either plastic or glass. We mount the shaft in a manner that prevents damage to the encoder.

They are also available with incremental optical encoders. It allows for incrementing rotation and gives you more control over your application.

3. Magnetic Absolute Encoders
Magnetic absolute encoders use magnetic fields to determine how far the shaft has rotated.

These are great for applications with high precision. They need a higher level of accuracy.

You can even use them with low speeds and are excellent if you need to determine the position of your motor under extreme conditions.

This type of encoder is usually more expensive but can be worth it if you need that level of accuracy in your application.

Incremental Encoder
Incremental rotary encoders are less expensive than absolute encoders. But, they only provide incremental rotation.

This means they only tell you which direction of rotation is happening but not how many turns there are.

They are perfect for applications that do not need to know the exact position of your motor, such as a refrigerator motor. They also allow for repeatable adjustments in your application to maintain the same level of accuracy.

It is important to note that the resolution of incremental rotary encoders is usually not as high as that of absolute encoders.

Incremental rotary encoders typically have a center detent. This means that when we “home” our motor, our index will be at noon.

They are simple to use and are the first option you should consider if you only need to determine rotation.

They are less expensive than absolute encoders and can be very small.

Rotary Encoders vs. Potentiometer
Rotary encoders can measure rotation in a small space.

Because of their limited space, rotary encoders make it challenging to achieve the precise positions we want.

Using a potentiometer instead, we can easily achieve precise positions. You do this by mounting the motor to our PCB and adjusting the potentiometer from there. Then we can “home” our motor by turning the potentiometer to its center position.

Potentiometers are great if you want to achieve exact positioning but not give us feedback on the absolute position. Therefore, we must use a rotary encoder and feedback the Arduino data to accomplish this task.

In our application, the sensor’s output is 8 bits of data, and our program will then translate them into 0’s and 1’s.

We know that the Arduino will always return 1’s when the encoder is home and 0 when not.

We can use a 16-bit program to do this translation, if we account for the limitations of the rotary encoder Arduino.

There are libraries available to help with this translation, and you can find them through your Arduino IDE.

How Can Outputs Help You?
Outputs are an essential part of any robotics application. They allow us to track what is happening in our applications to make adjustments as necessary. This will save time as we troubleshoot during the development process.

The outputs also allow our programs to make decisions and change their behavior accordingly. For example, a digital output can tell us when our motor is home and idle. This will allow us to open the circuit to our devices without overheating the motor. If the motor is not home, it can tell us by turning off the relay. We can also generally expect our program to decide on its own whether it should run at low speed or high speed. That decision will depend on how long the motor has been running.

More info:

https://www.kingfordpcb.com/technology-blog/which-arduino-pin-for-vex-encoder-signal/