From f176fe59d96da34aee4d60d10c928db7ed3b7e5a Mon Sep 17 00:00:00 2001
From: Frantisek Burian <BuFran@seznam.cz>
Date: Sat, 14 Dec 2013 19:16:17 +0100
Subject: [PATCH] [EXAMPLE:F0] Add simple button example

---
 .../f0/stm32f0-discovery/button/Makefile      | 25 +++++++
 .../stm32/f0/stm32f0-discovery/button/README  |  8 ++
 .../f0/stm32f0-discovery/button/button.c      | 75 +++++++++++++++++++
 3 files changed, 108 insertions(+)
 create mode 100644 examples/stm32/f0/stm32f0-discovery/button/Makefile
 create mode 100644 examples/stm32/f0/stm32f0-discovery/button/README
 create mode 100644 examples/stm32/f0/stm32f0-discovery/button/button.c

diff --git a/examples/stm32/f0/stm32f0-discovery/button/Makefile b/examples/stm32/f0/stm32f0-discovery/button/Makefile
new file mode 100644
index 0000000..d4625be
--- /dev/null
+++ b/examples/stm32/f0/stm32f0-discovery/button/Makefile
@@ -0,0 +1,25 @@
+##
+## This file is part of the libopencm3 project.
+##
+## Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
+##
+## This library is free software: you can redistribute it and/or modify
+## it under the terms of the GNU Lesser General Public License as published by
+## the Free Software Foundation, either version 3 of the License, or
+## (at your option) any later version.
+##
+## This library is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU Lesser General Public License for more details.
+##
+## You should have received a copy of the GNU Lesser General Public License
+## along with this library.  If not, see <http://www.gnu.org/licenses/>.
+##
+
+BINARY = button
+
+LDSCRIPT = ../stm32f0-discovery.ld
+
+include ../../Makefile.include
+
diff --git a/examples/stm32/f0/stm32f0-discovery/button/README b/examples/stm32/f0/stm32f0-discovery/button/README
new file mode 100644
index 0000000..f082444
--- /dev/null
+++ b/examples/stm32/f0/stm32f0-discovery/button/README
@@ -0,0 +1,8 @@
+------------------------------------------------------------------------------
+README
+------------------------------------------------------------------------------
+
+This example blinks the green LED on the ST STM32F0DISCOVERY eval board.
+
+When you press the 'USER' button, the blinking is slower.
+
diff --git a/examples/stm32/f0/stm32f0-discovery/button/button.c b/examples/stm32/f0/stm32f0-discovery/button/button.c
new file mode 100644
index 0000000..6386d28
--- /dev/null
+++ b/examples/stm32/f0/stm32f0-discovery/button/button.c
@@ -0,0 +1,75 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>,
+ * Copyright (C) 2010 Piotr Esden-Tempski <piotr@esden.net>
+ * Copyright (C) 2011 Stephen Caudle <scaudle@doceme.com>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <libopencm3/stm32/rcc.h>
+#include <libopencm3/stm32/gpio.h>
+
+/* Set STM32 to 48 MHz. */
+static void clock_setup(void)
+{
+	rcc_clock_setup_in_hsi_out_48mhz();
+}
+
+static void gpio_setup(void)
+{
+	/* Enable GPIOD clock. */
+	rcc_periph_clock_enable(RCC_GPIOC);
+
+
+	/* Set GPIO12 (in GPIO port D) to 'output push-pull'. */
+	gpio_mode_setup(GPIOC, GPIO_MODE_OUTPUT,
+			GPIO_PUPD_NONE, GPIO8 | GPIO9);
+}
+
+static void button_setup(void)
+{
+	/* Enable GPIOA clock. */
+	rcc_periph_clock_enable(RCC_GPIOA);
+
+
+	/* Set GPIO0 (in GPIO port A) to 'input open-drain'. */
+	gpio_mode_setup(GPIOA, GPIO_MODE_INPUT, GPIO_PUPD_NONE, GPIO0);
+}
+
+int main(void)
+{
+	int i;
+
+	clock_setup();
+	button_setup();
+	gpio_setup();
+
+	/* Blink the LED (PD12) on the board. */
+	while (1) {
+		gpio_toggle(GPIOC, GPIO8);
+
+		/* Upon button press, blink more slowly. */
+		if (gpio_get(GPIOA,GPIO0)) {
+			for (i = 0; i < 300000; i++)	/* Wait a bit. */
+				__asm__("nop");
+		}
+
+		for (i = 0; i < 300000; i++)		/* Wait a bit. */
+			__asm__("nop");
+	}
+
+	return 0;
+}