Teensy 4.x H/W Quadrature Encoder Library

[mjs513]

I have a library based on NXP Quad Encoder SDK driver for the Encoder module but modified to support the Teensy 4.x infrastructure.

NOTE: you will need to incorporate the Update imxrt.h for encoder structure #402 to make use of the library.

There are 4 hardware quadrature encoders available the Teensy 4.0. These are currently supported on FlexIO pins: 0, 1, 2, 3, 4, 5, 7, 30, 31 and 33. The library is available in my GitHub repository: https://github.com/mjs513/Teensy-4.x...ncoder-Library.


Basic usuage for the T4 is similar to the current Teensy Encoder library.

QuadEncoder myEnc(enc, pin1, pin2); 
   enc - encoder object (specify 1, 2, 3 or 4).
   pin1 - phase A
   pin2 - phase b
myEnc.read();
   Returns the accumulated position. This number can be positive or negative. 
myEnc.write(newPosition);
   Set the accumulated position to a new number.

A similar to example to that on https://www.pjrc.com/teensy/td_libs_Encoder.html is shown below. See SimpleEncoder.ino in the examples folder.

//
* http://www.pjrc.com/teensy/td_libs_Encoder.html
*
* This example code is in the public domain.
*/

#include "Quadencoder.h"

// Change these pin numbers to the pins connected to your encoder.
// Allowable encoder pins:
// 0, 1, 2, 3, 4, 5, 7, 30, 31 and 33
// Encoder on channel 1 of 4 available
// Phase A (pin0), PhaseB(pin1), 
QuadEncoder knobLeft(1, 0, 1);
// Encoder on channel 2 of 4 available
//Phase A (pin2), PhaseB(pin3), Pullups Req(0)
QuadEncoder knobRight(2, 2, 3);
//   avoid using pins with LEDs attached

void setup() {
 Serial.begin(9600);
 Serial.println("TwoKnobs Encoder Test:");
 /* Initialize Encoder/knobLeft. */
 knobLeft.setInitConfig();
 //Optional filter setup
 //knobLeft.EncConfig.filterCount = 5;
 //knobLeft.EncConfig.filterSamplePeriod = 255;
 knobLeft.init();
 /* Initialize Encoder/knobRight. */
 knobRight.setInitConfig();
 //knobRight.EncConfig.filterCount = 5;
 //knobRight.EncConfig.filterSamplePeriod = 255;
 knobRight.init();
}

long positionLeft  = -999;
long positionRight = -999;

void loop() {
 long newLeft, newRight;
 newLeft = knobLeft.read();
 newRight = knobRight.read();
 if (newLeft != positionLeft || newRight != positionRight) {
   Serial.print("Left = ");
   Serial.print(newLeft);
   Serial.print(", Right = ");
   Serial.print(newRight);
   Serial.println();
   positionLeft = newLeft;
   positionRight = newRight;
 }
 // if a character is sent from the serial monitor,
 // reset both back to zero.
 if (Serial.available()) {
   Serial.read();
   Serial.println("Reset both knobs to zero");
   knobLeft.write(0);
   knobRight.write(0);
 }
}

Using two KY-040 Rotary Encoder Module was tested:

with the following output on the serial monitor:


In addition a Rotary Encoder with Different Resolutions (200PPR, Line driver with 5V was used to test the index pin functionality:


A few examples are included in the library showing its capabilities.

Enjoy. Let me know if you run into any problems.

[luni]

That's very useful indeed. I will certainly test it with high resolution encoders as soon as I find some time.
If you want to do some performance testing I have a Teensy quadrature tester on gitHub https://github.com/luni64/EncSim



It generates encoder signals up to some 1.4MHz and can simulate random bouncing and non 90° signals. Details in the GitHub readme

[mjs513]

@luni

Thanks for the link to the encoder sim. Just took a quick look and impressive. Just downloaded it and will give it a try later today.

[DerekR]

Excellent! However, I have been using the PJRC Encoder library successfully (no missing steps) with the T4 in an application with two encoders for several weeks now. Is there any reason to switch?

[mjs513]

@DerekR

If the PRJC Encoder Library is working I really don't see any reason to switch. It does have the advantage of being able to use any pair of digital pins while the Hardware Encoder library is limited to the available pins. There are a bunch more bells and whistles if you need them though. Plus it only has 4 hw encoders that you can use. For most of my applications - robotics will probably continue using the PRJC Encoder Library. Guess it goes back to the old saying "the right tool for the right job"

[iamtawon]

I have been working with PJRC Encoder library with Arduino UNO earlier but now I'm moving to Teensy4.0. the encoder is hall effect encoder but I don't think that's the problem( yet)

#include <Encoder.h>

Encoder pitch(1,2);
long pitch_count ;

void setup() {
  // put your setup code here, to run once:
pinMode(1, INPUT);    //Pitch Encoder signal1
pinMode(2, INPUT);    //Pitch Encoder signal2
pinMode(3, OUTPUT);    //AIN1
pinMode(4, OUTPUT);    //AIN2
pinMode(5, OUTPUT);    //PWMA
pinMode(6, OUTPUT);    //MotorEnable

Serial.begin(9600);
pitch.write(0);// reset encoder counter to 0

}

void loop() {
      digitalWrite(3, LOW);   //AIN1
      digitalWrite(4, HIGH);  //AIN2
      analogWrite(5, 80);     //PWMA
      digitalWrite(6, HIGH);  //MotorEnable
      pitch_count = pitch.read(); //get pitch count reading
      Serial.println(pitch_count);
}

with this simple code I've got error message

Arduino: 1.8.10 (Windows 10), TD: 1.48, Board: "Teensy 4.0, Serial, 600 MHz, Faster, US English"

In file included from C:\Users\USER\Documents\Arduino\Pipe\Teensy\MotorEncoder2\MotorEncoder2.ino:1:0:

C:\Users\USER\Documents\Arduino\Pipe\libraries\Encoder/Encoder.h: In constructor 'Encoder::Encoder(uint8_t, uint8_t)':

C:\Users\USER\Documents\Arduino\Pipe\libraries\Encoder/Encoder.h:82:25: error: cannot convert 'volatile uint32_t* {aka volatile long unsigned int*}' to 'volatile uint8_t* {aka volatile unsigned char*}' in assignment

   encoder.pin1_register = PIN_TO_BASEREG(pin1);

                         ^

C:\Users\USER\Documents\Arduino\Pipe\libraries\Encoder/Encoder.h:84:25: error: cannot convert 'volatile uint32_t* {aka volatile long unsigned int*}' to 'volatile uint8_t* {aka volatile unsigned char*}' in assignment

   encoder.pin2_register = PIN_TO_BASEREG(pin2);

                         ^

Multiple libraries were found for "Encoder.h"
 Used: C:\Users\USER\Documents\Arduino\Pipe\libraries\Encoder
 Not used: C:\Program
Error compiling for board Teensy 4.0.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

any pointer of how to solve this?

P.S. if I change board setting to Teensy 3.6 or Arduino Uno it will compile fine.
It's running on window10, Arduino 1.8.10, Teensyduino 1.48

[iamtawon]

I've also try Teensy4.0 Quadencoder library by running the example twoknob code I've got Error compling code for board teensy4.0

Arduino: 1.8.10 (Windows 10), TD: 1.48, Board: "Teensy 4.0, Serial, 600 MHz, Faster, US English"

C:\Program Files (x86)\Arduino\arduino-builder -dump-prefs -logger=machine -hardware C:\Program Files (x86)\Arduino\hardware -tools C:\Program Files (x86)\Arduino\tools-builder -tools C:\Program Files (x86)\Arduino\hardware\tools\avr -built-in-libraries C:\Program Files (x86)\Arduino\libraries -libraries C:\Users\USER\Documents\Arduino\Pipe\libraries -fqbn=teensy:avr:teensy40:usb=serial,speed=600,opt= o2std,keys=en-us -ide-version=10810 -build-path C:\Users\USER\AppData\Local\Temp\arduino_build_833 932 -warnings=default -build-cache C:\Users\USER\AppData\Local\Temp\arduino_cache_832 200 -verbose C:\Users\USER\Documents\Arduino\Pipe\Teensy\MotorE ncoder2\MotorEncoder2.ino
C:\Program Files (x86)\Arduino\arduino-builder -compile -logger=machine -hardware C:\Program Files (x86)\Arduino\hardware -tools C:\Program Files (x86)\Arduino\tools-builder -tools C:\Program Files (x86)\Arduino\hardware\tools\avr -built-in-libraries C:\Program Files (x86)\Arduino\libraries -libraries C:\Users\USER\Documents\Arduino\Pipe\libraries -fqbn=teensy:avr:teensy40:usb=serial,speed=600,opt= o2std,keys=en-us -ide-version=10810 -build-path C:\Users\USER\AppData\Local\Temp\arduino_build_833 932 -warnings=default -build-cache C:\Users\USER\AppData\Local\Temp\arduino_cache_832 200 -verbose C:\Users\USER\Documents\Arduino\Pipe\Teensy\MotorE ncoder2\MotorEncoder2.ino
Using board 'teensy40' from platform in folder: C:\Program
Using core 'teensy4' from platform in folder: C:\Program
Detecting libraries used...
"C:\\Program Files (x86)\\Arduino\\hardware\\teensy/../tools/arm/bin/arm-none-eabi-g++" -E -CC -x c++ -w -g -Wall -ffunction-sections -fdata-sections -nostdlib -std=gnu++14 -fno-exceptions -fpermissive -fno-rtti -fno-threadsafe-statics -felide-constructors -Wno-error=narrowing -mthumb -mcpu=cortex-m7 -mfloat-abi=hard -mfpu=fpv5-d16 -D__IMXRT1062__ -DTEENSYDUINO=148 -DARDUINO=10810 -DF_CPU=600000000 -DUSB_SERIAL -DLAYOUT_US_ENGLISH "-IC:\\Program Files (x86)\\Arduino\\hardware\\teensy\\avr\\cores\\teen sy4" "C:\\Users\\USER\\AppData\\Local\\Temp\\arduino_bu ild_833932\\sketch\\MotorEncoder2.ino.cpp" -o nul
Alternatives for Quadencoder.h: [Teensy-4.x-Quad-Encoder-Library-master]
ResolveLibrary(Quadencoder.h)
-> candidates: [Teensy-4.x-Quad-Encoder-Library-master]
"C:\\Program Files (x86)\\Arduino\\hardware\\teensy/../tools/arm/bin/arm-none-eabi-g++" -E -CC -x c++ -w -g -Wall -ffunction-sections -fdata-sections -nostdlib -std=gnu++14 -fno-exceptions -fpermissive -fno-rtti -fno-threadsafe-statics -felide-constructors -Wno-error=narrowing -mthumb -mcpu=cortex-m7 -mfloat-abi=hard -mfpu=fpv5-d16 -D__IMXRT1062__ -DTEENSYDUINO=148 -DARDUINO=10810 -DF_CPU=600000000 -DUSB_SERIAL -DLAYOUT_US_ENGLISH "-IC:\\Program Files (x86)\\Arduino\\hardware\\teensy\\avr\\cores\\teen sy4" "-IC:\\Users\\USER\\Documents\\Arduino\\Pipe\\librar ies\\Teensy-4.x-Quad-Encoder-Library-master" "C:\\Users\\USER\\AppData\\Local\\Temp\\arduino_bu ild_833932\\sketch\\MotorEncoder2.ino.cpp" -o nul
"C:\\Program Files (x86)\\Arduino\\hardware\\teensy/../tools/arm/bin/arm-none-eabi-g++" -E -CC -x c++ -w -g -Wall -ffunction-sections -fdata-sections -nostdlib -std=gnu++14 -fno-exceptions -fpermissive -fno-rtti -fno-threadsafe-statics -felide-constructors -Wno-error=narrowing -mthumb -mcpu=cortex-m7 -mfloat-abi=hard -mfpu=fpv5-d16 -D__IMXRT1062__ -DTEENSYDUINO=148 -DARDUINO=10810 -DF_CPU=600000000 -DUSB_SERIAL -DLAYOUT_US_ENGLISH "-IC:\\Program Files (x86)\\Arduino\\hardware\\teensy\\avr\\cores\\teen sy4" "-IC:\\Users\\USER\\Documents\\Arduino\\Pipe\\librar ies\\Teensy-4.x-Quad-Encoder-Library-master" "C:\\Users\\USER\\Documents\\Arduino\\Pipe\\librar ies\\Teensy-4.x-Quad-Encoder-Library-master\\Quadencoder.cpp" -o nul
Generating function prototypes...
"C:\\Program Files (x86)\\Arduino\\hardware\\teensy/../tools/arm/bin/arm-none-eabi-g++" -E -CC -x c++ -w -g -Wall -ffunction-sections -fdata-sections -nostdlib -std=gnu++14 -fno-exceptions -fpermissive -fno-rtti -fno-threadsafe-statics -felide-constructors -Wno-error=narrowing -mthumb -mcpu=cortex-m7 -mfloat-abi=hard -mfpu=fpv5-d16 -D__IMXRT1062__ -DTEENSYDUINO=148 -DARDUINO=10810 -DF_CPU=600000000 -DUSB_SERIAL -DLAYOUT_US_ENGLISH "-IC:\\Program Files (x86)\\Arduino\\hardware\\teensy\\avr\\cores\\teen sy4" "-IC:\\Users\\USER\\Documents\\Arduino\\Pipe\\librar ies\\Teensy-4.x-Quad-Encoder-Library-master" "C:\\Users\\USER\\AppData\\Local\\Temp\\arduino_bu ild_833932\\sketch\\MotorEncoder2.ino.cpp" -o "C:\\Users\\USER\\AppData\\Local\\Temp\\arduino_bu ild_833932\\preproc\\ctags_target_for_gcc_minus_e. cpp"
"C:\\Program Files (x86)\\Arduino\\tools-builder\\ctags\\5.8-arduino11/ctags" -u --language-force=c++ -f - --c++-kinds=svpf --fields=KSTtzns --line-directives "C:\\Users\\USER\\AppData\\Local\\Temp\\arduino_bu ild_833932\\preproc\\ctags_target_for_gcc_minus_e. cpp"
Compiling sketch...
"C:\\Program Files (x86)\\Arduino\\hardware\\teensy/../tools/precompile_helper" "C:\\Program Files (x86)\\Arduino\\hardware\\teensy\\avr/cores/teensy4" "C:\\Users\\USER\\AppData\\Local\\Temp\\arduino_bu ild_833932" "C:\\Program Files (x86)\\Arduino\\hardware\\teensy/../tools/arm/bin/arm-none-eabi-g++" -x c++-header -O2 -g -Wall -ffunction-sections -fdata-sections -nostdlib -MMD -std=gnu++14 -fno-exceptions -fpermissive -fno-rtti -fno-threadsafe-statics -felide-constructors -Wno-error=narrowing -mthumb -mcpu=cortex-m7 -mfloat-abi=hard -mfpu=fpv5-d16 -D__IMXRT1062__ -DTEENSYDUINO=148 -DARDUINO=10810 -DF_CPU=600000000 -DUSB_SERIAL -DLAYOUT_US_ENGLISH "-IC:\\Program Files (x86)\\Arduino\\hardware\\teensy\\avr/cores/teensy4" "C:\\Users\\USER\\AppData\\Local\\Temp\\arduino_bu ild_833932/pch/Arduino.h" -o "C:\\Users\\USER\\AppData\\Local\\Temp\\arduino_bu ild_833932/pch/Arduino.h.gch"
"C:\\Program Files (x86)\\Arduino\\hardware\\teensy/../tools/arm/bin/arm-none-eabi-g++" -c -O2 -g -Wall -ffunction-sections -fdata-sections -nostdlib -MMD -std=gnu++14 -fno-exceptions -fpermissive -fno-rtti -fno-threadsafe-statics -felide-constructors -Wno-error=narrowing -mthumb -mcpu=cortex-m7 -mfloat-abi=hard -mfpu=fpv5-d16 -D__IMXRT1062__ -DTEENSYDUINO=148 -DARDUINO=10810 -DF_CPU=600000000 -DUSB_SERIAL -DLAYOUT_US_ENGLISH "-IC:\\Users\\USER\\AppData\\Local\\Temp\\arduino_bu ild_833932/pch" "-IC:\\Program Files (x86)\\Arduino\\hardware\\teensy\\avr\\cores\\teen sy4" "-IC:\\Users\\USER\\Documents\\Arduino\\Pipe\\librar ies\\Teensy-4.x-Quad-Encoder-Library-master" "C:\\Users\\USER\\AppData\\Local\\Temp\\arduino_bu ild_833932\\sketch\\MotorEncoder2.ino.cpp" -o "C:\\Users\\USER\\AppData\\Local\\Temp\\arduino_bu ild_833932\\sketch\\MotorEncoder2.ino.cpp.o"
In file included from C:\Users\USER\Documents\Arduino\Pipe\Teensy\MotorE ncoder2\MotorEncoder2.ino:1:0:

C:\Users\USER\Documents\Arduino\Pipe\libraries\Tee nsy-4.x-Quad-Encoder-Library-master/Quadencoder.h:146:12: error: 'IMXRT_ENC_t' does not name a type

volatile IMXRT_ENC_t* ENC;

^

Multiple libraries were found for "Quadencoder.h"
Used: C:\Users\USER\Documents\Arduino\Pipe\libraries\Tee nsy-4.x-Quad-Encoder-Library-master
Using library Teensy-4.x-Quad-Encoder-Library-master in folder: C:\Users\USER\Documents\Arduino\Pipe\libraries\Tee nsy-4.x-Quad-Encoder-Library-master (legacy)
Error compiling for board Teensy 4.0.

I wonder if my setting is wrong? since so many people using both encoder libray without such problem, how can I check?

[defragster]

I've also try Teensy4.0 Quadencoder library by running the example twoknob code I've got Error compling code for board teensy4.0

…
C:\Users\USER\Documents\Arduino\Pipe\libraries\Tee nsy-4.x-Quad-Encoder-Library-master/Quadencoder.h:146:12: error: 'IMXRT_ENC_t' does not name a type

volatile IMXRT_ENC_t* ENC;
...

I wonder if my setting is wrong? since so many people using both encoder libray without such problem, how can I check?

See post #1 :: "NOTE: you will need to incorporate the Update imxrt.h for encoder structure #402 to make use of the library."
That type define was added to that file.

[PaulStoffregen]

This message is trying to tell you something...

Multiple libraries were found for "Encoder.h"
Used: C:\Users\USER\Documents\Arduino\Pipe\libraries\Enc oder
Not used: C:\Program

Arduino is using a copy you installed in Documents\Arduino\Pipe\libraries (which is probably an old version from before Teensy 4.0 existed), and it's ignoring the copy Teensyduino installed (in a folder that didn't copy completely from the window to your message here on the forum).

Try moving or deleting the copy of Encoder from Documents\Arduino\Pipe\libraries, so Arduino will use the one from Teensyduino.

[defragster]

This message is trying to tell you something...

Arduino is using a copy you installed in Documents\Arduino\Pipe\libraries (which is probably an old version from before Teensy 4.0 existed), and it's ignoring the copy Teensyduino installed (in a folder that didn't copy completely from the window to your message here on the forum).

Try moving or deleting the copy of Encoder from Documents\Arduino\Pipe\libraries, so Arduino will use the one from Teensyduino.

Paul - he did that before I posted the same about 'private lib' - from this thread he is using the newest by @mjs513 in post #7 :: C:\Users\USER\Documents\Arduino\Pipe\libraries\Tee nsy-4.x-Quad-Encoder-Library-master

What was missed is the change as noted in post #1 - ref in post #8 - needed PULL request update for imxrt.h

[iamtawon]

This message is trying to tell you something...



Arduino is using a copy you installed in Documents\Arduino\Pipe\libraries (which is probably an old version from before Teensy 4.0 existed), and it's ignoring the copy Teensyduino installed (in a folder that didn't copy completely from the window to your message here on the forum).

Try moving or deleting the copy of Encoder from Documents\Arduino\Pipe\libraries, so Arduino will use the one from Teensyduino.

this solve the problem! now I can run the "classic" Teensy encoder on Teensy 4.0 many thanks!

and for Quadencoder library for teensy4.X
"See post #1 :: "NOTE: you will need to incorporate the Update imxrt.h for encoder structure #402 to make use of the library."That type define was added to that file."
I notice that but I have no idea what it was and how to it since I did not have imrt.h in the library folder. any guidance would be appreciate here.

[mjs513]

The "imxrt.h" file is part of the teensy cores files which is installed when you install Teensyduino.

For me the path looks like "F:\arduino-1.8.10\hardware\teensy\avr\cores\teensy4". So essentially navigate to your Arduino IDE folder go to the hardware directory - then teensy directory - then avr directory - then cores directory then the teensy4 directory and you will see the "imxrt.h" file

[luni]

I finally found time to try your lib.
I tested it with count rates up to 1 MHz and randomly switching direction. I also tried phase angles as small as 10° and bounced signal transitions.
So far I didn't observe any lost count so it seems to work pretty perfectly.

Just one small improvement suggestion: The read function should return an int not an unsigned. Casting of course is no problem, but the inexperienced user might get confused by seeing strange numbers doing something like Serial.println(enc.read())

[mjs513]

@luni
Thank for testing and glad its working. I forget to post that I did play around with your test sketch and seemed to be working. Got side tracked on other diversions which is way too common lately.

I did make the change as you suggested and updated the GitHub repository with the change.

Thanks again for testing.

[luni]

Thanks for the quick fix.

[mrbungle]

/* Hi!
I'm new here and new on coding, so...
hello all.
Sorry in advance for silly questions and thanks in advance for the boring effort of helping newbies.
I will do my best in searching before asking here ok? */

I was tinkering with your library but my encoder always returns two numbers per click (either positive or negative) I suppose is because my encoder has more clicks than expected.
Can I change this somewhere in this library?

This is the encoder data:
http://www.song-huei.com.tw/pdfimage...2S-English.pdf

And this is my code:

#include "QuadEncoder.h"  //Library info:    https://github.com/mjs513/Teensy-4.x-Quad-Encoder-Library

QuadEncoder encoder(1, 0, 1, 1); // Quadrature Decoder Number(1), PhaseA(pin0), PhaseB(pin1), Pullups Req(1)

void setup() {
  
 Serial.begin(9600);
 
  encoder.setInitConfig(); // Initialize Encoder
  encoder.EncConfig.filterCount = 7; //Debouncing filter setup     range 0-7
  encoder.EncConfig.filterSamplePeriod = 255; //Debouncing filter setup     range 0-255
  
 encoder.init();
 
}

long positionEncoder  = -999;

void loop() {
 long newLeft;
 newLeft = encoder.read();
 if (newLeft != positionEncoder) {
   Serial.print(newLeft);
   Serial.println();
   positionEncoder = newLeft;
 }

}

[luni]

A lot of mechanical encoders produce two or more increments/decrements per detent by design. I assume this is because they can keep the switch part of the encoder and only change the detent "wheel" for generating product variants.
In those cases I usually do a simple

newLeft = encoder.read() /n;

where n is the number of steps per detent;

[mjs513]

Couldn't have said any better than @luni

[mrbungle]

@Luni:
It works like a charm!
Many thanks

[JNivard]

Hai

I recently have a linear scale for my home made CNC machine. I wonder if a can use this library for a linear scale it has the A and B pins and a R pin. I think the R pin is triggered at the beginning of the scale. The resolution of the linear scale is 1/1000 mm. I have a teensy 4 and connected a oled screen and that is working. My question is if I can use the Teensy 4.x H/W Quadrature Encoder Library for this purpose and can it process the number of pulses that comes from the linear scale

John

[mjs513]

@JNivard
Sorry for the delay. Never used one of those at 1/1000mm resolution before but it should work. Remember that the T4 is 3.3v not 5v. I used a level shifter for that. If you try it let us know if it works at that resolution.

[JNivard]

@JNivard
Sorry for the delay. Never used one of those at 1/1000mm resolution before but it should work. Remember that the T4 is 3.3v not 5v. I used a level shifter for that. If you try it let us know if it works at that resolution.

Thanks, I will show the results

John

[TeensyWolf]

Probably a silly question, but this Encoder library is used to Decode quadrature from an encoder?

The name is somewhat confusing to me. On the 3.2, I used QuadDecode. Looking for same thing with the 4.0.

Thanks.

[mjs513]

Never used QuadDecode library but from what I see it does the same thing as the current Encoder library, i.e., reading the encoders signals. The encoder library is kind of the standard that I have been using. The Quadrature Encoder library is the same as the encoder library but done in hardware with a few more bells a whistles. Take a look at the readme for the Quadrature encoder library and a look at the Teensy Encoder library: https://www.pjrc.com/teensy/td_libs_Encoder.html

[TeensyWolf]

Never used QuadDecode library but from what I see it does the same thing as the current Encoder library, i.e., reading the encoders signals. The encoder library is kind of the standard that I have been using. The Quadrature Encoder library is the same as the encoder library but done in hardware with a few more bells a whistles. Take a look at the readme for the Quadrature encoder library and a look at the Teensy Encoder library: https://www.pjrc.com/teensy/td_libs_Encoder.html

I see that now. Thanks for confirming.

Perhaps the nomenclature would be clearer if it said "quadrature encoder/decoder" to match up with the NXP docs.