PCF8574: Reading from multiple encoders

[poki]

First of all, want to thank you for creating this great library!
I’m trying to get two encoders to work, with following setups:

int encoderPinA = P0;
int encoderPinB = P1;
int encoderPinC = P2;
int encoderPinD = P3;
pcf8574.encoder(encoderPinA, encoderPinB);
pcf8574.encoder(encoderPinC, encoderPinD); And read values by calling these functions:

pcf8574.readEncoderValue(encoderPinA, encoderPinB, &encoderValue1)
pcf8574.readEncoderValue(encoderPinC, encoderPinD, &encoderValue2)

However, the encoderValue1 and encoderValue2 can only goes up, no matter which direction I turn, but if with only one encoder, it works fine (clockwise +1 & counter -1)

Wondering if you could give some suggestions what I can implement this?

Cheers!

[Renzo Mischianti]

Hi Poky,
I never test the internal implementation with 2 encoder, It’s possible that there is a bug,

to bypass the problem you can try to implement externally the management of 2 encoder, there is an example of external implementation on the relative tutorial

PCF8574 i2c digital I/O expander: Arduino, esp8266 and esp32, rotary encoder

But I try to fix as soon as possible.

Bye Renzo

[Renzo Mischianti]

Hi poki,
change this lines

// Select an algorithm to manage encoder progression

#define BASIC_ENCODER_ALGORITHM

//#define MISCHIANTI_ENCODER_ALGORITHM

comment MISCHIANTI_ENCODER_ALGORITHM and decomment BASIC_ENCODER_ALGORITHM, and give me a feedback.

Thanks Renzo

[poki]

Hi Renzo, basic encoder algorithm is still doing the same (only increment when rotate)
However I get by this problem by modify the if statement as following:

if (na && !nb) {
if (encoderPinBLast) *encoderValue = *encoderValue + 1;
else *encoderValue = *encoderValue - 1;
changed = true;
}

Now both encoders are working correctly, thanks!

[Renzo Mischianti]

Hi Poki,
thanks for your solution, but your solution not work with my encoder, the first encoder only increment when rotate, the second work correctly.
I think there are some difference from the encoder, so I’m going to add you r algorithm to the library for all people that have your same type of encoder.
Now we have:

#define POKI_ENCODER_ALGORITHM
//#define BASIC_ENCODER_ALGORITHM
//#define MISCHIANTI_ENCODER_ALGORITHM

Thanks for your support.

[poki]

Hi Renzo,

The strange thing is that if I only used a single encoder, the original algorithm works fine (01-10 clockwise, 01-11 counter)
But whenever I connected two encoders, the behavior changed to (00-10 counter)
Do have you a spare encoder to test when two connected? Thanks!

[Renzo Mischianti]

Hi poki,
I had tested with 2 encoder and BASIC_ENCODER_ALGORITHM work fine for me, but with yours first encoder only increase.

But I’m going to to do more test.

Bye Renzo

[Renzo Mischianti]

There is another bug

byte encoderValues = B00000000;

must be

volatile byte encoderValues = B00000000;

Try It also please.
Thanks Renzo

[poki]

Hi Renzo,

I’ve changed the PCF8574.h file as advised, but still the same

[Renzo Mischianti]

Hi Poki,
I checked and tested various encoder, and I have had multiple response different from different encoder.
So my solution to cover is this:

 #define BASIC_ENCODER_ALGORITHM
// #define MISCHIANTI_ENCODER_ALGORITHM
// #define SEQUENCE_ENCODER_ALGORITHM_REDUCED
// #define SEQUENCE_ENCODER_ALGORITHM
// #define POKI_ENCODER_ALGORITHM

I give the possibility to use different algorithm for different encoder like this

void updateEncoder(){
    changed2 = pcf8574.readEncoderValueSequenceReduced(P6, P5, &encoderValue2);
    changed = pcf8574.readEncoderValue(encoderPinA, encoderPinB, &encoderValue, true);

//  int vale = pcf8574.readEncoderValue(encoderPinA, encoderPinB);
//  if (vale!=0){
//      changed = true;
//  }
//  encoderValue = encoderValue + vale;

    bool val = pcf8574.digitalRead(P2);
    if (val!=valPrec){
      changed = true;
      valPrec = val;
      encoderButtonVal = val;
    }
    bool val2 = pcf8574.digitalRead(P4);
    if (val2!=valPrec2){
      changed2 = true;
      valPrec2 = val2;
      encoderButtonVal2 = val2;
    }
}

With this solution I can use different modules and different encoders with succes.

Give me a feedbback.
Bye Renzo

[poki]

Renzo, it works with the “reverseRotation” set true, but sometimes when turn clockwise, it will count -1

[Renzo Mischianti]

Hi Poki,
if you have some exception on the behavior probably It’s the noise, the encoders have a lot of noise.
Try to change the algorithm, or add some capacitor to absorb It.
Bye Renzo

[Author]

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