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Added timer example that generates a variable frequency signal. In that particular case it is generating the SOS morse code on the eval board led.

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This commit is contained in:
Piotr Esden-Tempski 2011-02-20 18:02:19 -08:00
parent 662e77b4ee
commit 6694f3dc0c
4 changed files with 243 additions and 2 deletions
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8
examples/stm32/stm32-h103/Makefile
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@ -24,7 +24,7 @@ Q := @
MAKEFLAGS += --no-print-directory
endif
all: miniblink fancyblink usart usart_irq usart_printf usart_irq_printf usb_cdcacm usb_hid button exti_both
all: miniblink fancyblink usart usart_irq usart_printf usart_irq_printf timer usb_cdcacm usb_hid button exti_both
miniblink:
@printf " BUILD examples/stm32/stm32-h103/miniblink\n"
@ -50,6 +50,10 @@ usart_irq_printf:
@printf " BUILD examples/stm32/stm32-h103/usart_irq_printf\n"
$(Q)$(MAKE) -C usart_irq_printf
timer:
@printf " BUILD examples/stm32/stm32-h103/timer\n"
$(Q)$(MAKE) -C timer
spi:
@printf " BUILD examples/stm32/stm32-h103/spi\n"
$(Q)$(MAKE) -C spi
@ -94,5 +98,5 @@ clean:
@printf " CLEAN examples/stm32/stm32-h103/exti_both\n"
$(Q)$(MAKE) -C exti_both clean
.PHONY: miniblink fancyblink usart usart_irq usart_printf usart_irq_printf spi usb_cdcacm usb_hid button exti_both clean
.PHONY: miniblink fancyblink usart usart_irq usart_printf usart_irq_printf timer spi usb_cdcacm usb_hid button exti_both clean

23
examples/stm32/stm32-h103/timer/Makefile Normal file
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@ -0,0 +1,23 @@
##
## This file is part of the libopencm3 project.
##
## Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
##
## This program is free software: you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
##
## This program 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 General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program. If not, see <http://www.gnu.org/licenses/>.
##
BINARY = timer
include ../../Makefile.include

183
examples/stm32/stm32-h103/timer/timer.c Normal file
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@ -0,0 +1,183 @@
/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2011 Piotr Esden-Tempski <piotr@esden.net>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/nvic.h>
#include <libopencm3/stm32/gpio.h>
#include <libopencm3/stm32/timer.h>
#include <libopencm3/stm32/exti.h>
u16 frequency_sequence[18] = {
1000,
500,
1000,
500,
1000,
500,
2000,
500,
2000,
500,
2000,
500,
1000,
500,
1000,
500,
1000,
5000
};
int frequency_sel = 0;
u16 compare_time;
u16 new_time;
u16 frequency;
int debug = 0;
void clock_setup(void)
{
rcc_clock_setup_in_hse_8mhz_out_72mhz();
}
void gpio_setup(void)
{
/* Enable GPIOC clock. */
rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPCEN);
/*
* Set GPIO12 (PORTC) (led) to
* 'output alternate function push-pull'.
*/
gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ,
GPIO_CNF_OUTPUT_PUSHPULL, GPIO12);
gpio_set(GPIOC, GPIO12);
}
void tim_setup(void)
{
/* Enable TIM2 clock. */
rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_TIM2EN);
/* Enable TIM2 interrupt. */
nvic_enable_irq(NVIC_TIM2_IRQ);
/* Reset TIM2 peripheral */
timer_reset(TIM2);
/* Timer global mode:
* - No divider
* - alignment edge
* - direction up
*/
timer_set_mode(TIM2, TIM_CR1_CKD_CK_INT,
TIM_CR1_CMS_EDGE,
TIM_CR1_DIR_UP);
/* Reset prescaler value. */
timer_set_prescaler(TIM2, 36000);
/* Enable preload. */
timer_disable_preload(TIM2);
/* Continous mode. */
timer_continuous_mode(TIM2);
/* Period (36kHz) */
timer_set_period(TIM2, 65535);
/* Disable outputs. */
timer_disable_oc_output(TIM2, TIM_OC1);
timer_disable_oc_output(TIM2, TIM_OC2);
timer_disable_oc_output(TIM2, TIM_OC3);
timer_disable_oc_output(TIM2, TIM_OC4);
/* -- OC1 configuration -- */
/* Configure global mode of line 1. */
timer_disable_oc_clear(TIM2, TIM_OC1);
timer_disable_oc_preload(TIM2, TIM_OC1);
timer_set_oc_slow_mode(TIM2, TIM_OC1);
timer_set_oc_mode(TIM2, TIM_OC1, TIM_OCM_FROZEN);
/* Set the capture compare value for OC1. */
timer_set_oc_value(TIM2, TIM_OC1, 1000);
/* ---- */
/* ARR reload enable */
timer_disable_preload(TIM2);
/* Counter enable */
timer_enable_counter(TIM2);
/* Enable commutation interrupt */
timer_enable_irq(TIM2, TIM_DIER_CC1IE);
}
void tim2_isr(void)
{
if (timer_get_flag(TIM2, TIM_SR_CC1IF)) {
/* Clear compare interrupt flag. */
timer_clear_flag(TIM2, TIM_SR_CC1IF);
/*
* Get current timer value to calculate next
* compare register value
*/
compare_time = timer_get_counter(TIM2);
/*
* Calculate and set the next compare value.
*/
frequency = frequency_sequence[frequency_sel++];
new_time = compare_time + frequency;
timer_set_oc_value(TIM2, TIM_OC1,
new_time);
if (frequency_sel == 18) {
frequency_sel = 0;
}
/* Toggle led to indicate compare event */
gpio_toggle(GPIOC, GPIO12);
}
}
int main(void)
{
clock_setup();
gpio_setup();
tim_setup();
while (1) {
__asm("nop");
}
return 0;
}

31
examples/stm32/stm32-h103/timer/timer.ld Normal file
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@ -0,0 +1,31 @@
/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* Linker script for Olimex STM32-H103 (STM32F103RBT6, 128K flash, 20K RAM). */
/* Define memory regions. */
MEMORY
{
rom (rx) : ORIGIN = 0x08000000, LENGTH = 128K
ram (rwx) : ORIGIN = 0x20000000, LENGTH = 20K
}
/* Include the common ld script. */
INCLUDE libopencm3_stm32.ld