[ws2812] resumable write and dma example

examples/stm32f469_discovery/ws2812b/main.cpp

@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2019, 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>
+#include <modm/driver/pwm/ws2812b.hpp>
+#include <modm/ui/led/tables.hpp>
+#include <modm/processing/timer.hpp>
+
+using namespace Board;
+
+using Output = Board::D11;
+modm::Ws2812b<SpiMaster2, Output, 8*8> leds;
+modm::ShortPeriodicTimer tmr{33ms};
+
+int
+main()
+{
+	Board::initialize();
+	LedD13::setOutput();
+	leds.initialize<Board::SystemClock>();
+
+	constexpr uint8_t max = 60;
+	uint8_t r=0, g=max/3, b=max/3*2;
+
+	while (true)
+	{
+		for (size_t ii=0; ii < leds.size; ii++)
+		{
+			leds.setColor(ii,
+						  {modm::ui::table22_8_256[r*3/2],
+						   modm::ui::table22_8_256[g*3/2],
+						   modm::ui::table22_8_256[b*3/2]});
+			if (r++ >= max) r = 0;
+			if (g++ >= max) g = 0;
+			if (b++ >= max) b = 0;
+		}
+		leds.write();
+
+		while(not tmr.execute()) ;
+		LedD13::toggle();
+	}
+
+	return 0;
+}

examples/stm32f469_discovery/ws2812b/project.xml

@@ -0,0 +1,13 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<library>
+  <extends>modm:disco-f469ni</extends>
+  <options>
+    <option name=":build:build.path">../../../build/stm32f469_discovery/ws2812b</option>
+  </options>
+  <modules>
+    <module>modm:driver:ws2812</module>
+    <module>modm:platform:spi:2</module>
+    <module>modm:ui:led</module>
+    <module>modm:build:scons</module>
+  </modules>
+</library>

examples/stm32f469_discovery/ws2812b_dma/main.cpp

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2019, Niklas Hauser
+ * Copyright (c) 2023, Henrik Hose
+ *
+ * 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>
+#include <modm/driver/pwm/ws2812b.hpp>
+#include <modm/ui/led/tables.hpp>
+#include <modm/processing/timer.hpp>
+#include <modm/processing.hpp>
+
+using namespace Board;
+
+using Output = Board::D11;
+using DmaRx = Dma1::Channel3;
+using DmaTx = Dma1::Channel4;
+using SpiLed = SpiMaster2_Dma<DmaRx, DmaTx>;
+// using SpiLed = SpiMaster2; // for non-dma version
+modm::Ws2812b<SpiLed, Output, 8*8> leds;
+modm::ShortPeriodicTimer tmr{33ms};
+
+constexpr uint8_t max = 62;
+uint8_t r=0, g=max/3, b=max/3*2;
+
+int
+main()
+{
+	Board::initialize();
+	LedD13::setOutput();
+	Dma1::enable();
+	leds.initialize<Board::SystemClock>();
+
+	constexpr uint8_t max = 60;
+	uint8_t r=0, g=max/3, b=max/3*2;
+
+	while (true)
+	{
+		for (size_t ii=0; ii < leds.size; ii++)
+		{
+			leds.setColor(ii,
+						  {modm::ui::table22_8_256[r*3/2],
+						   modm::ui::table22_8_256[g*3/2],
+						   modm::ui::table22_8_256[b*3/2]});
+			if (r++ >= max) r = 0;
+			if (g++ >= max) g = 0;
+			if (b++ >= max) b = 0;
+		}
+		leds.write();
+
+		while(not tmr.execute()) ;
+		// LedD13::toggle();
+	}
+
+	return 0;
+}

examples/stm32f469_discovery/ws2812b_dma/project.xml

@@ -0,0 +1,15 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<library>
+  <extends>modm:disco-f469ni</extends>
+  <options>
+    <option name=":build:build.path">../../../build/stm32f469_discovery/ws2812b_dma</option>
+  </options>
+  <modules>
+    <module>modm:driver:ws2812</module>
+    <module>modm:platform:spi:2</module>
+    <module>modm:platform:dma</module>
+    <module>modm:ui:led</module>
+    <module>modm:build:scons</module>
+    <module>modm:processing:timer</module>
+  </modules>
+</library>

src/modm/architecture/interface/spi_master.hpp

@@ -155,6 +155,7 @@ class SpiMaster : public ::modm::PeripheralDriver, public Spi
 	 */
 	static modm::ResumableResult<void>
 	transfer(const uint8_t *tx, uint8_t *rx, std::size_t length);
+
 #endif
 };
 

src/modm/driver/pwm/ws2812.lb

@@ -43,6 +43,7 @@ def prepare(module, options):
         ":architecture:spi",
         ":architecture:unaligned",
         ":math:units",
+        ":processing:resumable",
         ":ui:color")
     return options[":target"].identifier.platform == "stm32"
 

src/modm/driver/pwm/ws2812b.hpp

@@ -14,13 +14,14 @@
 #include <modm/architecture/interface/spi_master.hpp>
 #include <modm/architecture/interface/unaligned.hpp>
 #include <modm/ui/color.hpp>
+#include <modm/processing/resumable.hpp>
 
 namespace modm
 {
 
 /// @ingroup modm_driver_ws2812
 template< class SpiMaster, class Output, size_t LEDs >
-class Ws2812b
+class Ws2812b : protected modm::NestedResumable<3>
 {
 protected:								  // 7654 3210 7654 3210 7654 3210
 	static constexpr uint32_t base_mask  = 0b0010'0100'1001'0010'0100'1001;
@@ -100,14 +101,26 @@ class Ws2812b
 		return {color[1], color[0], color[2]};
 	}
 
-	void
+	modm::ResumableResult<void>
+	write()
+	requires (SpiMaster::usesDma())
+	{
+		RF_BEGIN();
+		RF_CALL(SpiMaster::transfer(data, nullptr, length+1));
+		RF_END_RETURN();
+	}
+
+	modm::ResumableResult<void>
 	write()
 	{
+		RF_BEGIN();
 		for (const auto value : data) {
 			while (not SpiMaster::Hal::isTransmitRegisterEmpty()) ;
 			SpiMaster::Hal::write(value);
 		}
+		RF_END_RETURN();
 	}
+
 };
 
 }	// namespace modm

src/modm/platform/spi/rp/spi_master_dma.hpp.in

@@ -84,6 +84,9 @@ public:
 		waitCompleted([](){});
 	}
 
+	static constexpr bool
+	usesDma(){return true;};
+
 private:
 	// needed for transfers where no RX or TX buffers are given
 	static inline uint8_t dmaDummy{0};

src/modm/platform/spi/stm32/spi_master.hpp.in

@@ -153,6 +153,7 @@ public:
 
 	static modm::ResumableResult<void>
 	transfer(const uint8_t *tx, uint8_t *rx, std::size_t length);
+
 };
 
 } // namespace platform

src/modm/platform/spi/stm32/spi_master_dma.hpp.in

@@ -74,6 +74,9 @@ public:
 	static modm::ResumableResult<void>
 	transfer(const uint8_t *tx, uint8_t *rx, std::size_t length);
 
+	static constexpr bool
+	usesDma(){return true;};
+
 private:
 	static void
 	handleDmaTransferError();