[examples] Add RTC example on NUCLEO-G071RB/G474RE

Author: salkinium

examples/generic/rtc/main.cpp

@@ -0,0 +1,40 @@
+// coding: utf-8
+/*
+ * Copyright (c) 2023, Rasmus Kleist Hørlyck Sørensen
+ * Copyright (c) 2024, Niklas Hauser
+ *
+ * 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/.
+ */
+// ----------------------------------------------------------------------------
+
+#include <modm/board.hpp>
+
+int
+main()
+{
+	Board::initialize();
+	MODM_LOG_INFO << "Initialize RTC" << modm::endl;
+	Rtc::initialize<Board::SystemClock>();
+
+	constexpr auto cdt = modm::DateTime::fromBuildTime();
+	MODM_LOG_INFO << "Compile DateTime: " << cdt << modm::endl;
+	// MODM_LOG_INFO << "Compile Weekday: " << cdt.weekday().c_encoding() << modm::endl;
+
+	if (Rtc::dateTime() < cdt) Rtc::setDateTime(cdt);
+
+	while (true)
+	{
+		const auto dt = Rtc::dateTime();
+		const auto now = Rtc::now();
+		MODM_LOG_INFO << dt << modm::endl;
+		MODM_LOG_INFO << now.time_since_epoch().count() << modm::endl;
+		// MODM_LOG_INFO << "Weekday: " << dt.weekday().c_encoding() << modm::endl;
+		modm::delay(0.9s);
+	}
+
+	return 0;
+}

examples/generic/rtc/project.xml

@@ -0,0 +1,11 @@
+<library>
+	<extends>modm:nucleo-g071rb</extends>
+	<!-- <extends>modm:nucleo-g474re</extends> -->
+	<options>
+		<option name="modm:build:build.path">../../../build/generic/rtc</option>
+	</options>
+	<modules>
+		<module>modm:platform:rtc</module>
+		<module>modm:build:scons</module>
+	</modules>
+</library>

src/modm/board/nucleo_g071rb/board.hpp

@@ -72,16 +72,20 @@ struct SystemClock
 	static constexpr uint32_t Spi2		= Apb;
 	static constexpr uint32_t Iwdg		= Rcc::LsiFrequency;
 	static constexpr uint32_t Wwdg		= Apb;
-	static constexpr uint32_t Rtc		= Apb;
 	static constexpr uint32_t Timer14	= Apb;
 	static constexpr uint32_t Timer7	= Apb;
 	static constexpr uint32_t Timer6	= Apb;
 	static constexpr uint32_t Timer3	= Apb;
 	static constexpr uint32_t Timer2	= Apb;
 
+	static constexpr uint32_t Rtc = 32.768_kHz;
+
 	static bool inline
 	enable()
 	{
+		Rcc::enableLowSpeedExternalCrystal();
+		Rcc::enableRealTimeClock(Rcc::RealTimeClockSource::LowSpeedExternalCrystal);
+
 		Rcc::enableInternalClock();	// 16MHz
 		// (internal clock / 1_M) * 8_N / 2_R = 128MHz / 2 = 64MHz
 		const Rcc::PllFactors pllFactors{

src/modm/board/nucleo_g474re/board.hpp

@@ -66,7 +66,6 @@ struct SystemClock
 	static constexpr uint32_t I2c4      = I2c;
 	static constexpr uint32_t Lptim     = Apb1;
 	static constexpr uint32_t Lpuart    = Apb1;
-	static constexpr uint32_t Rtc       = Apb1;
 	static constexpr uint32_t Spi2      = Apb1;
 	static constexpr uint32_t Spi3      = Apb1;
 	static constexpr uint32_t Uart4     = Apb1;
@@ -94,6 +93,8 @@ struct SystemClock
 	static constexpr uint32_t Timer20   = Apb2Timer;
 	static constexpr uint32_t Iwdg = Rcc::LsiFrequency;
 
+	static constexpr uint32_t Rtc = 32.768_kHz;
+
 	static bool inline
 	enable()
 	{
@@ -115,6 +116,9 @@ struct SystemClock
 		// update frequencies for busy-wait delay functions
 		Rcc::updateCoreFrequency<Frequency>();
 
+		Rcc::enableLowSpeedExternalCrystal();
+		Rcc::enableRealTimeClock(Rcc::RealTimeClockSource::LowSpeedExternalCrystal);
+
 		Rcc::setCanClockSource(Rcc::CanClockSource::Pclk);
 		return true;
 	}