Sensors/rotary-encoder/render.cpp

Rotary Encoder

Connect a rotary encoder to Bela's digital inputs, detect the direction of the rotation, and keep track of how far you've gone.

If your encoder has a built-in switch, you can use that to reset the current count.

/*
 ____  _____ _        _
| __ )| ____| |      / \
|  _ \|  _| | |     / _ \
| |_) | |___| |___ / ___ \
|____/|_____|_____/_/   \_\
http://bela.io
*/
 
#include <Bela.h>
#include <libraries/Scope/Scope.h>
#include <libraries/Encoder/Encoder.h>
 
Encoder gEncoder;
Scope gScope;
// Bela digital input channels connected to the encoder and button
unsigned int kEncChA = 0;
unsigned int kEncChB = 1;
unsigned int kEncChBtn = 2;
 
// adjust the values below based on your encoder and wiring
unsigned int kDebouncingSamples = 15;
Encoder::Polarity polarity = Encoder::ANY; // could be ANY, ACTIVE_LOW, ACTIVE_HIGH
 
bool setup(BelaContext *context, void *userData)
{
        gScope.setup(3, context->audioSampleRate);
        gEncoder.setup(kDebouncingSamples, polarity);
 
        // Set the digital pins to inputs
        pinMode(context, 0, kEncChA, INPUT);
        pinMode(context, 0, kEncChB, INPUT);
        pinMode(context, 0, kEncChBtn, INPUT);
        return true;
}
 
bool gButton;
unsigned int holdoff;
void render(BelaContext *context, void *userData)
{
        for(unsigned int n=0; n<context->digitalFrames; n++){
                bool a = digitalRead(context, n, kEncChA);
                bool b = digitalRead(context, n, kEncChB);
                bool button = digitalRead(context, n, kEncChBtn);
                Encoder::Rotation ret = gEncoder.process(a, b);
                if(Encoder::NONE != ret)
                {
                        rt_printf("%s : %3d\n", Encoder::CCW == ret ? "ccw" : "cw ", gEncoder.get());
                }
                if(gButton != button) {
                        gButton = button;
                        if(button) {
                                gEncoder.reset();
                                rt_printf("reset : %3d\n", gEncoder.get());
                        }
                }
                if(1)
                {
                        if(Encoder::CCW == ret)
                                button = 1;
                        else
                                button = 0;
 
                }
                gScope.log( // log the values with a vertical offset to make them easier to see
                        a * 0.5 + 0.333,
                        b * 0.5 - 0.333,
                        button * 0.5 - 0.88
                );
        }
}
 
void cleanup(BelaContext *context, void *userData)
{
}