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Diffstat (limited to 'examples/stm32/f1/obldc-strip/systick/systick.c')
-rw-r--r--examples/stm32/f1/obldc-strip/systick/systick.c81
1 files changed, 81 insertions, 0 deletions
diff --git a/examples/stm32/f1/obldc-strip/systick/systick.c b/examples/stm32/f1/obldc-strip/systick/systick.c
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+++ b/examples/stm32/f1/obldc-strip/systick/systick.c
@@ -0,0 +1,81 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2012 Piotr Esden-Tempski <piotr@esden.net>
+ *
+ * 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/f1/rcc.h>
+#include <libopencm3/stm32/f1/flash.h>
+#include <libopencm3/stm32/f1/gpio.h>
+#include <libopencm3/cm3/nvic.h>
+#include <libopencm3/cm3/systick.h>
+
+u32 temp32;
+
+void gpio_setup(void)
+{
+ /* Enable alternate function peripheral clock. */
+ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_AFIOEN);
+
+ /* Enable GPIOB clock. */
+ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPBEN);
+
+ gpio_clear(GPIOB, GPIO4); /* LED green on */
+ gpio_set(GPIOB, GPIO5); /* LED red off */
+
+ /* Set GPIO4/5 (in GPIO port B) to 'output push-pull' for the LEDs. */
+ gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ,
+ GPIO_CNF_OUTPUT_PUSHPULL, GPIO4);
+ gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ,
+ GPIO_CNF_OUTPUT_PUSHPULL, GPIO5);
+
+ AFIO_MAPR |= AFIO_MAPR_SWJ_CFG_FULL_SWJ_NO_JNTRST;
+}
+
+void sys_tick_handler(void)
+{
+ temp32++;
+
+ /* We call this handler every 1ms so 1000ms = 1s on/off. */
+ if (temp32 == 1000) {
+ gpio_toggle(GPIOB, GPIO4); /* LED green on/off */
+ gpio_toggle(GPIOB, GPIO5); /* LED red on/off */
+ temp32 = 0;
+ }
+}
+
+int main(void)
+{
+ rcc_clock_setup_in_hsi_out_64mhz();
+ gpio_setup();
+
+ temp32 = 0;
+
+ /* 64MHz / 8 => 8000000 counts per second */
+ systick_set_clocksource(STK_CTRL_CLKSOURCE_AHB_DIV8);
+
+ /* 8000000/8000 = 1000 overflows per second - every 1ms one interrupt */
+ systick_set_reload(8000);
+
+ systick_interrupt_enable();
+
+ /* Start counting. */
+ systick_counter_enable();
+
+ while (1); /* Halt. */
+
+ return 0;
+}