Added encoder.hpp

src/modm/driver/encoder/encoder.hpp

@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2021, Thomas Sommer
+ *
+ * This file is part of the modm project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+// ----------------------------------------------------------------------------
+
+#ifndef MODM_ENCODER_HPP
+#define MODM_ENCODER_HPP
+
+#include <modm/platform.hpp>
+#include <type_traits>
+
+namespace modm
+{
+/**
+ * \brief	Encoder
+ *
+ * \ingroup	modm_ui_encoder
+ * \author	2021 Thomas Sommer
+ */
+struct encoder
+{
+	typedef enum Division
+	{
+		ONE,
+		TWO,
+		FOUR
+	} Division_t;
+};
+
+template<typename PH_A, typename PH_B, encoder::Division_t DIVISION,
+		 typename UnderlyingType = int8_t>
+class Encoder
+{
+public:
+	Encoder() : enc_delta(0), raw_last(0) {};
+
+	inline void
+	connect()
+	{
+		PH_A::setInput(::Gpio::InputType::PullUp);
+		PH_B::setInput(::Gpio::InputType::PullUp);
+
+		// Tare power-on state
+		modm::delay(10us);
+		UnderlyingType raw = 0;
+		if (PH_A::read()) raw = 3;
+		if (PH_B::read()) raw ^= 1;
+		raw_last = raw;
+	}
+
+	// Call @1kHz for manual movement
+	inline void
+	update();
+
+	UnderlyingType
+	getValue();
+
+private:
+	UnderlyingType enc_delta;
+	UnderlyingType raw_last;
+};
+}  // namespace modm
+
+#include "encoder_impl.hpp"
+
+#endif  // MODM_ENCODER_HPP

src/modm/driver/encoder/encoder.lb

@@ -0,0 +1,27 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# Copyright (c) 2019, Thomas Sommer
+#
+# This file is part of the modm project.
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+# -----------------------------------------------------------------------------
+
+def init(module):
+    module.name = ":driver:encoder"
+    module.description = """
+Software graycode ported from C-Code of Peter Dannegger:
+https://www.mikrocontroller.net/articles/Drehgeber.
+"""
+
+def prepare(module, options):
+    module.depends(":architecture:atomic")
+    return True
+
+def build(env):
+    env.outbasepath = "modm/src/modm/driver/encoder"
+    env.copy("encoder.hpp")
+    env.copy("encoder_impl.hpp")

src/modm/driver/encoder/encoder_impl.hpp

@@ -0,0 +1,49 @@
+#ifndef MODM_ENCODER_HPP
+#error "Don't include this file directly, use 'encoder.hpp' instead!"
+#endif
+
+template<typename PH_A, typename PH_B, modm::encoder::Division_t DIVISION, typename UnderlyingType>
+inline void
+modm::Encoder<PH_A, PH_B, DIVISION, UnderlyingType>::update()
+{
+	static_assert(std::is_signed<UnderlyingType>::value and std::is_integral<UnderlyingType>::value,
+				  "UnderlyingType must be signed integral");
+	// Tare on power-on
+	UnderlyingType raw = 0;
+	UnderlyingType diff;
+
+	if (PH_A::read()) raw = 3;
+	if (PH_B::read()) raw ^= 1;  // convert gray to binary
+
+	diff = raw_last - raw;
+	if (diff & 1)
+	{
+		raw_last = raw;               // store new as next last
+		enc_delta += (diff & 2) - 1;  // bit 1 = direction (+/-)
+	}
+}
+
+template<typename PH_A, typename PH_B, modm::encoder::Division_t DIVISION, typename UnderlyingType>
+UnderlyingType
+modm::Encoder<PH_A, PH_B, DIVISION, UnderlyingType>::getValue()
+{
+	static_assert(std::is_signed<UnderlyingType>::value and std::is_integral<UnderlyingType>::value,
+				  "UnderlyingType must be signed integral");
+	cli();
+	UnderlyingType val = enc_delta;  // counts since last call
+	switch (DIVISION)
+	{
+		case encoder::Division::ONE:
+			enc_delta = 0;
+			break;
+		case encoder::Division::TWO:
+			enc_delta = val & 1;
+			val >>= 1;
+			break;
+		case encoder::Division::FOUR:
+			enc_delta = val & 3;
+			val >>= 2;
+	}
+	sei();
+	return val;
+}