project 2 pasted in to repo

src/rotary_encoder_driver.cpp

@@ -0,0 +1,136 @@
+#include "rotary_encoder_driver.h"
+#include <avr/interrupt.h>
+
+RotaryEncoderDriver* driver = nullptr;
+
+RotaryEncoderDriver::RotaryEncoderDriver()
+    : cycle(0)
+    , count(0)
+    , prev_count(0)
+    , speed_ready(false)
+    , hist_idx(0)
+    , led(5)
+    , eA(2)
+    , eB(5)
+{
+    for (uint8_t i = 0; i < HIST_LEN; i++) {
+        history[i] = 0;
+    }
+}
+
+
+void RotaryEncoderDriver::begin() {
+    driver = this;
+
+    led.init();
+    eA.init();
+    eB.init();
+
+    EICRA |= (1<<ISC01) | (1<<ISC00);
+    EIMSK |= (1<<INT0);
+
+    timer.init(4000);
+}
+
+void RotaryEncoderDriver::update() {
+    count += eB.is_hi() ? 1 : -1;
+    led.set_hi();
+}
+
+int RotaryEncoderDriver::position() {
+
+    uint8_t oldSREG = SREG;
+
+    cli();
+
+    int16_t local_count = count;
+
+    SREG = oldSREG;
+
+    led.set_lo();
+
+    return local_count;
+} 
+
+void RotaryEncoderDriver::update_delta() {
+
+    int16_t oldest = history[hist_idx];
+    history[hist_idx] = count;
+    hist_idx = (hist_idx + 1) % HIST_LEN;
+
+    delta = count - oldest;   // breyting yfir HIST_LEN * Ts (40 ms) glugga
+
+    prev_count = count;
+
+    speed_ready = true;
+
+    led.set_lo();
+}
+
+float RotaryEncoderDriver::count_per_sec() {
+
+    uint8_t oldSREG = SREG;
+
+    cli();
+
+    int16_t local_delta = delta;
+
+    SREG = oldSREG;
+
+    return local_delta / (HIST_LEN * 0.004f);
+}
+
+
+float RotaryEncoderDriver::rpm()
+{
+    const float COUNTS_PER_REV = 1050.0f;
+
+    return count_per_sec() * 60.0f / COUNTS_PER_REV;
+}
+
+bool RotaryEncoderDriver::new_speed_available()
+{
+    uint8_t oldSREG = SREG;
+
+    cli();
+
+    bool ready = speed_ready;
+
+    if (ready)
+    {
+        speed_ready = false;
+    }
+
+    SREG = oldSREG;
+
+    return ready;
+}
+
+
+void RotaryEncoderDriver::reset_speed_measurement()
+{
+    uint8_t oldSREG = SREG;
+
+    cli();
+
+    cycle = 0;
+    prev_count = count;
+    delta = 0;
+    speed_ready = false;
+
+    for (uint8_t i = 0; i < HIST_LEN; i++) {
+        history[i] = count;
+    }
+    hist_idx = 0;
+
+    SREG = oldSREG;
+}
+
+ISR(INT0_vect) {
+    driver->update();
+}
+ISR(TIMER1_COMPA_vect) {
+    driver->update_delta();    
+}
+
+