No datasheet for popular encoder

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1

Looking for a datasheet for this encoder:

I'm having issues trying to figure out how to wire it up correctly. I have a/b directly into digital pins, but it's not reading the left/right movements for some reason. I saw someone mentioning 330k or 10k resistors on the q&a but can't find anything concrete as nothing works. Looking for support on this.

2

I suppose you read this

do the best I can without photos. One side has two pins. That is the pushbutton +&- (positive & ground). simple
What's hard is the 3 pin side.
A, C, B (left, center, right).
A connects to CLK (GPIO pin) directly, and is also connected to a + bus via a 330Ohm resistor
B connects to DT (GPIO pin) directly & is also connected to the + bus via 330Ohm resistor
C connects directly to ground

The resistor they mention is internal just ignore that comment and connect the center pin to GND and left and right to two pins like 2 and 3 on a UNO and Use the encoder library

For the other side where you have two pins, connect one to pin 4 and the other to ground and in your setup do

pinMode(4, INPUT_PULLUP);

Then read that pin with digitalRead() and it will be LOW when the button is pressed

3

Hi

This model of yours appears to be similar to this one:

ref: Rotary Encoder + Extras : ID 377 : $4.50 : Adafruit Industries, Unique & fun DIY electronics and kits

4

oh thank god. I'm so glad the resistors are internal. Still though, not sure why it isn't working... I'll post my code below:

int switchPin = 7;                        // button pin
int switchState = HIGH;                    // button value

int pinA = 4;                              // Rotary encoder Pin A
int pinB = 6;                              // Rotary encoder Pin B
int pinAstateCurrent = LOW;                // Current state of Pin A
int pinAStateLast = pinAstateCurrent;      // Last read value of Pin A
int total = 0;

void setup() {
  Serial.begin (9600);                     // Initialise the serial monitor

  pinMode (switchPin, INPUT_PULLUP);       // Enable the switchPin as input with a PULLUP resistor
  
  pinMode (pinA, INPUT);                   // Set PinA as input
  pinMode (pinB, INPUT);                   // Set PinB as input
  
}

void loop() {

  // BUTTON
  switchState = digitalRead(switchPin);    // Read the digital value of the switch (LOW/HIGH)

  // If the switch is pressed (LOW), print message
  if (switchState == LOW) {
      Serial.println("Switch pressed");
  }
  

  // ROTATION DIRECTION
  pinAstateCurrent = digitalRead(pinA);    // Read the current state of Pin A
  
  // If there is a minimal movement of 1 step
  if ((pinAStateLast == LOW) && (pinAstateCurrent == HIGH)) {
    
    if (digitalRead(pinB) == HIGH) {      // If Pin B is HIGH
      Serial.println("Left");             // Print on screen
      total = total + 1;
      Serial.println(total);
    } else {
      Serial.println("Right");            // Print on screen
      total = total - 1;
      Serial.println(total);
    }
    
  }
  
  pinAStateLast = pinAstateCurrent;        // Store the latest read value in the currect state variable
  
}
5

Hi @rap10c

Are you currently holding the button down?

" if ((pinAStateLast == LOW) && (pinAstateCurrent == HIGH)) {"

6

I'm not sure I follow... are you saying that I need to hold the button down to show the turns? Obviously that's not the case here. I do notice that if I wiggle the wires, sometimes it triggers it as a turn. However that's just me messing with the leads. Is there an easy way to show a schematic of my wiring?

Edit: best I can do right now is show a circuit.io link: https://www.circuito.io/app?components=512,11021,860025
(ignore the code)

7

Draw it on a piece of paper, take a picture and drag and drop the picture in your post

8

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