[ws2812] resumable function example and bug

Author: hshose

examples/nucleo_f411re/ws2812b_dma/main.cpp

@@ -0,0 +1,84 @@
+/*
+ * 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>
+#include <modm/processing.hpp>
+
+using namespace Board;
+
+using Output = Board::D11;
+using DmaRx = Dma2::Channel0;
+using DmaTx = Dma2::Channel3;
+using SpiLed = SpiMaster1_Dma<DmaRx, DmaTx>;
+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;
+
+class Ws2812Thread : public modm::pt::Protothread
+{
+public:
+
+	bool
+	update()
+	{
+		PT_BEGIN();
+
+		LedD13::setOutput();
+		Dma2::enable();
+		leds.initialize<Board::SystemClock>();
+
+		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;
+			}
+			PT_CALL(leds.write());
+
+			LedD13::toggle();
+			timeout.restart(500ms);
+			PT_WAIT_UNTIL(timeout.isExpired());
+		}
+
+		PT_END();
+	}
+
+private:
+	modm::ShortTimeout timeout;
+};
+
+Ws2812Thread ws2812_thread;
+
+int
+main()
+{
+	Board::initialize();
+
+
+
+	while (true)
+	{
+		ws2812_thread.update();
+	}
+
+	return 0;
+}

examples/nucleo_f411re/ws2812b_dma/project.xml

@@ -0,0 +1,16 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<library>
+  <extends>modm:nucleo-f411re</extends>
+  <options>
+    <option name=":build:build.path">../../../build/nucleo_f411re/ws2812b_dma</option>
+  </options>
+  <modules>
+    <module>modm:driver:ws2812</module>
+    <module>modm:platform:spi:1</module>
+    <module>modm:platform:dma</module>
+    <module>modm:ui:led</module>
+    <module>modm:build:scons</module>
+    <module>modm:processing:protothread</module>
+    <module>modm:processing:timer</module>
+  </modules>
+</library>

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

@@ -21,7 +21,7 @@ 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;
@@ -104,7 +104,9 @@ class Ws2812b
 	modm::ResumableResult<void>
 	write()
 	{
-		return SpiMaster::transfer(data, nullptr, length+1);
+		RF_BEGIN();
+		RF_CALL(SpiMaster::transfer(data, nullptr, length+1));
+		RF_END_RETURN();
 	}
 };