[example] Simple example using HX711 driver

examples/stm32f103c8t6_blue_pill/weight_scale_hx711/main.cpp

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+/*
+ * Copyright (c) 2020, Sascha Schade
+ *
+ * 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/debug/logger.hpp>
+#include <modm/processing/timer.hpp>
+#include <modm/processing/protothread.hpp>
+#include <modm/driver/adc/hx711.hpp>
+using namespace modm::literals;
+
+using namespace Board;
+
+// ----------------------------------------------------------------------------
+// Set the log level
+#undef	MODM_LOG_LEVEL
+#define	MODM_LOG_LEVEL modm::log::DEBUG
+
+// Create an IODeviceWrapper around the Uart Peripheral we want to use
+modm::IODeviceWrapper< Usart1, modm::IOBuffer::BlockIfFull > loggerDevice;
+
+// Set all four logger streams to use the UART
+modm::log::Logger modm::log::debug(loggerDevice);
+modm::log::Logger modm::log::info(loggerDevice);
+modm::log::Logger modm::log::warning(loggerDevice);
+modm::log::Logger modm::log::error(loggerDevice);
+
+
+struct hx711_config : public modm::hx711::Config
+{
+	using Sck  = GpioOutputA9;
+	using Data = GpioInputA10;
+	// static const modm::hx711::InputChannelAndGain mode = modm::hx711::InputChannelAndGain::ChA_64;
+};
+using Hx711 = modm::Hx711< hx711_config >;
+
+class Hx711Thread : public modm::pt::Protothread
+{
+public:
+	bool
+	run()
+	{
+		PT_BEGIN();
+
+		while (true)
+		{
+			result = PT_CALL(hx711.singleConversion());
+			MODM_LOG_DEBUG.printf("%" PRIi32 "\n", result);
+		}
+
+		PT_END();
+	}
+
+protected:
+	Hx711 hx711;
+	int32_t result;
+};
+
+Hx711Thread hx711_thread;
+
+
+class BlinkThread : public modm::pt::Protothread
+{
+public:
+	bool
+	run()
+	{
+		PT_BEGIN();
+
+		while (true) {
+			PT_WAIT_UNTIL(timer.execute());
+			LedGreen::toggle();
+		}
+
+		PT_END();
+	}
+
+protected:
+	modm::ShortPeriodicTimer timer{1'000};
+};
+
+BlinkThread blink_thread;
+
+
+/*
+ * Blinks the green user LED with 1 Hz while measuring.
+ *
+ * Make the following connections to HX711:
+ *   Data PA10
+ *   Clock PA9
+ */
+int
+main()
+{
+	Board::initialize();
+
+	// Initialize Uart1 for MODM_LOG_*
+	Usart1::connect<GpioOutputB6::Tx, GpioInputB7::Rx>();
+	Usart1::initialize<Board::SystemClock, 115200_Bd>();
+
+	// Use the logging streams to print some messages.
+	MODM_LOG_DEBUG   << "HX711 demo"   << modm::endl;
+
+	hx711_config::Sck::setOutput();
+	hx711_config::Data::setInput();
+
+	LedGreen::set();
+
+	while (true)
+	{
+		blink_thread.run();
+		hx711_thread.run();
+	}
+
+	return 0;
+}

examples/stm32f103c8t6_blue_pill/weight_scale_hx711/openocd.cfg

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+# Replace this with your custom programmer
+source [find interface/stlink-v2.cfg]

examples/stm32f103c8t6_blue_pill/weight_scale_hx711/project.xml

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+<library>
+  <extends>modm:blue-pill</extends>
+  <options>
+    <option name="modm:build:build.path">../../../build/stm32f103c8t6_blue_pill/weight_scale_hx711</option>
+    <option name="modm:build:openocd.cfg">openocd.cfg</option>
+  </options>
+  <modules>
+    <module>modm:debug</module>
+    <module>modm:platform:gpio</module>
+    <module>modm:platform:uart:1</module>
+    <module>modm:processing:timer</module>
+    <module>modm:processing:protothread</module>
+    <module>modm:build:scons</module>
+    <module>modm:driver:hx711</module>
+  </modules>
+</library>