HW-040 encoder module for ARDUINO

The HW-040 (KY-040) module consists of a rotation angle sensor (encoder) and auxiliary electrical components for stable operation of the sensor. An encoder is a mechanical sensor that reports the angle of rotation, rotation speed and direction of the axis of various devices. This module can be used to control servos or stepper motors.
The HW-040 module has 20 fixed positions per revolution. These positions represent a small click when the encoder axis is rotated. The rotation angle sensor has 3 outputs, which are designated (A, B, C). The principle of operation of the encoder is to change the positions of the switches. One switch is responsible for connecting pins A and B, and the second for pins B and C. Each change in the position of the sensor axis changes the states of the switches. In addition, the encoder is equipped with a button that works when the shaft is pressed. The button can be used to select menu items of the device or to change the sensitivity of the sensor.

A low TTL level appears on the sensor when the contacts are closed, then zero is applied to the CLK and DT pins. A high logic level is generated when a 5V supply voltage is applied. Pins CLK and DT transmit data about the rotation of the axis in the direction of clockwise or counterclockwise.

CLK: encoder pin A
DT: encoder pin B
SW: defines the state of the button
VCC (+): supply voltage
GND: ground (pin C)
As a power source, you can use an external power supply, the Arduino platform, or any other microcontroller device.
Supply voltage, V 3 ... 15
Number of fixed positions 20
Axle diameter, mm 6
Module dimensions, mm 20 x 30 x 30.