1 files changed, 107 insertions, 0 deletions
diff --git a/rotaryencoder.cpp b/rotaryencoder.cpp
new file mode 100644
index 0000000..41d56e8
--- /dev/null
+++ b/rotaryencoder.cpp
@@ -0,0 +1,107 @@
+#include "rotaryencoder.h"
+
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+#include <vector>
+
+#include <QDebug>
+#include <QElapsedTimer>
+
+#include <wiringPi.h>
+
+// got from https://gist.github.com/ast/a19813fce9d34c7240091db11b8190dd
+// https://gist.github.com/ast
+// Inspired by Paul Stoffregen's excellent Arduino library Encoder:
+// https://github.com/PaulStoffregen/Encoder
+
+constexpr int gpioA = 17;
+constexpr int gpioB = 27;
+// constexpr int gpioA = 0;
+// constexpr int gpioB = 2;
+// constexpr int gpioA = 11;
+// constexpr int gpioB = 13;
+
+const std::vector<int> encoderTable = {
+    0, 1, -1, 0, -1, 0, 0, 1, 1, 0, 0, -1, 0, -1, 1, 0
+};
+
+volatile int64_t positionSteps;
+volatile uint8_t state;
+
+void pin_isr(void) {
+    uint8_t p1val = digitalRead(gpioA);
+    uint8_t p2val = digitalRead(gpioB);
+    uint8_t s = state & 3;
+
+    if (p1val) s |= 4;
+    if (p2val) s |= 8;
+
+    state = (s >> 2);
+
+    switch (s) {
+    case 1: case 7: case 8: case 14:
+        positionSteps = positionSteps + 1;
+        return;
+    case 2: case 4: case 11: case 13:
+        positionSteps = positionSteps - 1;
+        return;
+    case 3: case 12:
+        positionSteps = positionSteps + 2;
+        return;
+    case 6: case 9:
+        positionSteps = positionSteps - 2;
+        return;
+    }
+}
+
+rotaryencoder::rotaryencoder()
+{
+    QElapsedTimer t;
+    t.start();
+
+    if (wiringPiSetupGpio()) {
+        perror("wiringPiSetupGpio");
+        exit(EXIT_FAILURE);
+    }
+
+    qDebug() << "msecs to setup wiringPi:" << t.elapsed();
+
+    if ( wiringPiISR (gpioA, INT_EDGE_BOTH, &pin_isr) < 0 ) {
+        perror("wiringPiISR");
+        exit(EXIT_FAILURE);
+    }
+
+    qDebug() << "msecs to register interruption A:" << t.elapsed();
+
+    if ( wiringPiISR (gpioB, INT_EDGE_BOTH, &pin_isr) < 0 ) {
+        perror("wiringPiISR");
+        exit(EXIT_FAILURE);
+    }
+
+    qDebug() << "msecs to register interruption B:" << t.elapsed();
+
+    // pinMode (gpioA,  INPUT) ;
+    // pinMode (gpioB,  INPUT) ;
+    // pullUpDnControl(gpioA, PUD_UP);
+    // pullUpDnControl(gpioB, PUD_UP);
+
+    qDebug() << "encoder is ok";
+
+    // // Show position every second
+    // while ( 1 ) {
+    //     constexpr double stepsPerMm = 200;
+    //     const double positionMm = ::positionSteps / stepsPerMm;
+    //     qDebug() << ::positionSteps
+    //              << '-'
+    //              << QString::number(positionMm, 'f', 3)
+    //              << "(mm)";
+    //     // printf( "%ld\n", ::position);
+    //     usleep( 100 * 1000 ); // wait 1 second
+    // }
+}
+
+int64_t rotaryencoder::position() const
+{
+    return ::positionSteps;
+}