I do not understand how to properly use the encoder with so many wires. I can sort of understand that the positive and negative are probably opposite signals from each other, sort of error protection or something? I know that the Z= and Z- are roattion counters at either 90, 180, or some other offset angle to allow ticking full rotations. But am unsure about this all and am reading a lot of material that is beyond me. I'm stumped.

With +5v supplied to it's wire and GND connected to 0v, rotating the motor shaft by hand, my meter reads:

• A+: +3.97v as the 'high' and +.036v as 'low'
• A-: same
• B+: same
• B-: same
• Z+: same - but only goes high at one location on the 360 degree
  rotation
• Z-: same - but only goes high at one location on the 360 degree rotation - the same location as Z+

NOTE: Both Z pulses coincide with pulses on A+, B+, and B- ... but those are NOT coincident on A-. So maybe A- has the Z+/- trigger in it's place? I don't know. It was VERY challenging to stop rotating the shaft AT a pulse because of the tiny size of the divisions.

All voltages seen by my digital multimeter were positive voltages.

I do not understand how to properly use the encoder with so many wires. I can sort of understand that the positive and negative are probably opposite signals from each other, sort of error protection or something? I know that the Z= and Z- are roattion counters at either 90, 180, or some other offset angle to allow ticking full rotations. But am unsure about this all and am reading a lot of material that is beyond me. I'm stumped.

I'm a total novice at arduino, and am mostly a copy/paste coder at this point - so of course this makes my goal harder.

I do not understand how to properly use the encoder with so many wires. I can sort of understand that the positive and negative are probably opposite signals from each other, sort of error protection or something? But am unsure and am reading a lot of material that is beyond me. I'm stumped.

. . . Can someone explain the function of, and how to use, all eight wires? . . .

I'm a total novice at arduino, and am mostly a copy/paste coder - so of course this makes my goal harder.

I do not understand how to properly use the encoder with so many wires. I can sort of understand that the positive and negative are probably opposite signals from each other, sort of error protection or something? I know that the Z= and Z- are roattion counters at either 90, 180, or some other offset angle to allow ticking full rotations. But am unsure about this all and am reading a lot of material that is beyond me. I'm stumped.

I can install the following code on an UNO and the UNO reads the encoder just fine off the A+ and B+ lines, with increasing count for one direction of rotation and decreasing count for the other direction. So it is reflecting the movement as it should...

BUT- I am getting 8000 pulses per shaft revolution rather than the 2000 pulses per revolution in the documentation. So something's not right here. I should see 2000 pulses per revolution... is this because of the lack of use of the other wires? Or something else?

Code i'm using for just A+ and B+:

    /*
*Quadrature Decoder 
*/
#include "Arduino.h"
#include <digitalWriteFast.h> 

// Quadrature encoders
// Left encoder
#define c_LeftEncoderInterruptA 0
#define c_LeftEncoderInterruptB 1
#define c_LeftEncoderPinA 2
#define c_LeftEncoderPinB 3
#define LeftEncoderIsReversed

volatile bool _LeftEncoderASet;
volatile bool _LeftEncoderBSet;
volatile bool _LeftEncoderAPrev;
volatile bool _LeftEncoderBPrev;
volatile long _LeftEncoderTicks = 0;

void setup()
{
  Serial.begin(9600);

  // Quadrature encoders
  // Left encoder
  pinMode(c_LeftEncoderPinA, INPUT);      // sets pin A as input
  digitalWrite(c_LeftEncoderPinA, LOW);  // turn on pullup resistors
  pinMode(c_LeftEncoderPinB, INPUT);      // sets pin B as input
  digitalWrite(c_LeftEncoderPinB, LOW);  // turn on pullup resistors
  attachInterrupt(c_LeftEncoderInterruptA, HandleLeftMotorInterruptA, CHANGE);
  attachInterrupt(c_LeftEncoderInterruptB, HandleLeftMotorInterruptB, CHANGE);
}

void loop()
{ 
  Serial.print("Encoder Ticks: ");
  Serial.print(_LeftEncoderTicks);
  Serial.print("  Revolutions: ");
  Serial.print(_LeftEncoderTicks/2000.0); //2000 Counts Per Revolution, per the engineering manual
  Serial.print("\n");
}


// Interrupt service routines for the left motor's quadrature encoder
void HandleLeftMotorInterruptA(){
  _LeftEncoderBSet = digitalReadFast(c_LeftEncoderPinB);
  _LeftEncoderASet = digitalReadFast(c_LeftEncoderPinA);
  
  _LeftEncoderTicks+=ParseEncoder();
  
  _LeftEncoderAPrev = _LeftEncoderASet;
  _LeftEncoderBPrev = _LeftEncoderBSet;
}

// Interrupt service routines for the right motor's quadrature encoder
void HandleLeftMotorInterruptB(){
  // Test transition;
  _LeftEncoderBSet = digitalReadFast(c_LeftEncoderPinB);
  _LeftEncoderASet = digitalReadFast(c_LeftEncoderPinA);
  
  _LeftEncoderTicks+=ParseEncoder();
  
  _LeftEncoderAPrev = _LeftEncoderASet;
  _LeftEncoderBPrev = _LeftEncoderBSet;
}

int ParseEncoder(){
  if(_LeftEncoderAPrev && _LeftEncoderBPrev){
    if(!_LeftEncoderASet && _LeftEncoderBSet) return 1;
    if(_LeftEncoderASet && !_LeftEncoderBSet) return -1;
  }else if(!_LeftEncoderAPrev && _LeftEncoderBPrev){
    if(!_LeftEncoderASet && !_LeftEncoderBSet) return 1;
    if(_LeftEncoderASet && _LeftEncoderBSet) return -1;
  }else if(!_LeftEncoderAPrev && !_LeftEncoderBPrev){
    if(_LeftEncoderASet && !_LeftEncoderBSet) return 1;
    if(!_LeftEncoderASet && _LeftEncoderBSet) return -1;
  }else if(_LeftEncoderAPrev && !_LeftEncoderBPrev){
    if(_LeftEncoderASet && _LeftEncoderBSet) return 1;
    if(!_LeftEncoderASet && !_LeftEncoderBSet) return -1;
  }
}

. . . Can someone explain the function of, and how to use, all eight wires? Explain why I'm getting 4X the counts that I should with that code above? PLEASE? . . .