From: Martin Mares <mj@ucw.cz>
Date: Tue, 30 Jul 2019 21:23:47 +0000 (+0200)
Subject: Timer 1 & 2
X-Git-Url: http://mj.ucw.cz/gitweb/?a=commitdiff_plain;h=bd0869a2d37beebab7a4633b0e5b2687509ad69e;p=home-hw.git

Timer 1 & 2
---

diff --git a/protab/timer1-clock/Makefile b/protab/timer1-clock/Makefile
new file mode 100644
index 0000000..9f34630
--- /dev/null
+++ b/protab/timer1-clock/Makefile
@@ -0,0 +1,6 @@
+ROOT=../..
+BINARY=timer
+OBJS=timer.o
+LIB_OBJS=
+
+include $(ROOT)/mk/bluepill.mk
diff --git a/protab/timer1-clock/timer.c b/protab/timer1-clock/timer.c
new file mode 100644
index 0000000..1042e46
--- /dev/null
+++ b/protab/timer1-clock/timer.c
@@ -0,0 +1,34 @@
+#include <libopencm3/stm32/rcc.h>
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/stm32/timer.h>
+
+static void delay_ms(unsigned int ms)
+{
+	timer_set_period(TIM3, 2*ms);
+	timer_enable_counter(TIM3);
+	while (TIM_CR1(TIM3) & TIM_CR1_CEN)
+		;
+}
+
+int main(void)
+{
+	rcc_clock_setup_in_hse_8mhz_out_72mhz();
+	rcc_periph_clock_enable(RCC_GPIOC);
+	rcc_periph_clock_enable(RCC_TIM3);
+
+	// PC13 = BluePill LED
+	gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO13);
+
+	timer_set_prescaler(TIM3, 35999);	// 72 MHz / 36000 = 2 kHz
+	timer_set_mode(TIM3, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_DOWN);
+	timer_one_shot_mode(TIM3);
+
+	for (;;) {
+		gpio_clear(GPIOC, GPIO13);
+		delay_ms(100);
+		gpio_set(GPIOC, GPIO13);
+		delay_ms(500);
+	}
+
+	return 0;
+}
diff --git a/protab/timer2-irq/Makefile b/protab/timer2-irq/Makefile
new file mode 100644
index 0000000..9f34630
--- /dev/null
+++ b/protab/timer2-irq/Makefile
@@ -0,0 +1,6 @@
+ROOT=../..
+BINARY=timer
+OBJS=timer.o
+LIB_OBJS=
+
+include $(ROOT)/mk/bluepill.mk
diff --git a/protab/timer2-irq/timer.c b/protab/timer2-irq/timer.c
new file mode 100644
index 0000000..86ad521
--- /dev/null
+++ b/protab/timer2-irq/timer.c
@@ -0,0 +1,36 @@
+#include <libopencm3/cm3/nvic.h>
+#include <libopencm3/stm32/rcc.h>
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/stm32/timer.h>
+
+void tim3_isr(void)
+{
+	if (TIM_SR(TIM3) & TIM_SR_UIF) {
+		TIM_SR(TIM3) &= ~TIM_SR_UIF;
+		gpio_toggle(GPIOC, GPIO13);
+	}
+}
+
+int main(void)
+{
+	rcc_clock_setup_in_hse_8mhz_out_72mhz();
+	rcc_periph_clock_enable(RCC_GPIOC);
+	rcc_periph_clock_enable(RCC_TIM3);
+
+	// PC13 = BluePill LED
+	gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO13);
+
+	timer_set_prescaler(TIM3, 35999);	// 72 MHz / 36000 = 2 kHz
+	timer_set_mode(TIM3, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_UP);
+	timer_set_period(TIM3, 199);		// 200 ticks = 100 ms
+	timer_update_on_overflow(TIM3);
+	timer_enable_irq(TIM3, TIM_DIER_UIE);
+	nvic_enable_irq(NVIC_TIM3_IRQ);
+	timer_enable_counter(TIM3);
+
+	for (;;) {
+		asm volatile ("wfi");
+	}
+
+	return 0;
+}