Improved example, using Timer for encoder.update()

examples/arduino_nano/encoder_input/main.cpp

@@ -11,24 +11,49 @@
 
 #include <modm/board.hpp>
 #include <modm/driver/encoder/encoder_input.hpp>
+#include <modm/math/algorithm/prescaler.hpp>
 #include <modm/processing/timer.hpp>
 
 using namespace modm::platform;
 
+// Connect the encoders outputs to D7 and D8 Pins (usually the outer pins)
+// The common third pin (usually in the middle) is connected to GND.
+// Don't add any resistors or filters. It's all in the MCU and the driver.
+modm::BitBangEncoderInput<Board::D7, Board::D8, modm::bitbang_encoder_input::Division::FOUR>
+	encoder;
+
+MODM_ISR(TIMER2_COMPA)
+{
+	encoder.update();
+}
+
+void
+init_Timer2()
+{
+	constexpr float f = 1_kHz;
+	constexpr auto inputDevice_prescaler =
+		modm::Prescaler::from_list(SystemClock::Timer, f * 2, {0, 1, 8, 32, 64, 128, 256, 1024});
+	constexpr auto ocr = (inputDevice_prescaler.frequency / f) - 1;
+	static_assert(ocr <= 255, "Can't configure Timer2 for desired f");
+
+	// Timer in CTC Mode
+	TCCR2A = (1 << WGM21);
+	OCR2A = ocr;
+	TIMSK2 |= (1 << OCIE2A);
+	TCCR2B |= inputDevice_prescaler.index;
+}
+
 int
 main()
 {
 	Board::initialize();
 	LedD13::setOutput();
 
-	// Connect the encoders outputs to D7 and D8 Pins (usually the outer pins)
-	// The common third pin (usually in the middle) is connected to GND.
-	// Don't add any resistors or filters. It's all in the MCU and the driver.
-	modm::BitBangEncoderInput<Board::D7, Board::D8, modm::bitbang_encoder_input::Division::FOUR>
-		encoder;
-
 	encoder.connect();
 
+	init_Timer2();
+	enableInterrupts();
+
 	int value(0);
 
 	modm::ShortPeriodicTimer heartbeat(500ms);
@@ -38,7 +63,6 @@ main()
 	while (true)
 	{
 		if (heartbeat.execute()) Board::LedD13::toggle();
-		if (encoderUpdate.execute()) encoder.update();
 		if (outputValue.execute())
 		{
 			value += encoder.getValue();