aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorKarl Palsson2013-01-23 00:01:46 +0000
committerKarl Palsson2013-01-23 00:01:46 +0000
commitd9fb4f7401b8bf546cc7e6ddeb9f22d343f0622d (patch)
treeb0932bb63bbfcc74e95e48c1ecf228eaddc0039e
parente5b32503825c53d278d09a34d7165020e1b5cad4 (diff)
Add examples making use of the RTC
Add an example using the RTC to help with a lower power design. This is a sister example to the existing "button-irq-printf", which is functionally identical, but uses far less power. There's more tricks that can be done to lower the power even further, but this shows a few of the early steps that can be done, using the RTC wakeup instead of a timer.
-rw-r--r--examples/stm32/f1/other/rtc/rtc.c2
-rw-r--r--examples/stm32/f1/stm32vl-discovery/rtc/rtc.c2
-rw-r--r--examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/Makefile24
-rw-r--r--examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/README18
-rw-r--r--examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/main.c300
-rw-r--r--examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/syscfg.h61
-rw-r--r--examples/stm32/l1/stm32l-discovery/button-irq-printf/README32
-rw-r--r--examples/stm32/l1/stm32l-discovery/button-irq-printf/main.c74
-rw-r--r--examples/stm32/l1/stm32l-discovery/button-irq-printf/syscfg.h5
-rw-r--r--include/libopencm3/stm32/l1/rcc.h1
-rw-r--r--lib/stm32/l1/rcc.c6
11 files changed, 508 insertions, 17 deletions
diff --git a/examples/stm32/f1/other/rtc/rtc.c b/examples/stm32/f1/other/rtc/rtc.c
index 41c5d89..9db114c 100644
--- a/examples/stm32/f1/other/rtc/rtc.c
+++ b/examples/stm32/f1/other/rtc/rtc.c
@@ -19,7 +19,7 @@
#include <libopencm3/stm32/f1/rcc.h>
#include <libopencm3/stm32/f1/gpio.h>
-#include <libopencm3/stm32/f1/rtc.h>
+#include <libopencm3/stm32/rtc.h>
#include <libopencm3/stm32/usart.h>
#include <libopencm3/stm32/pwr.h>
#include <libopencm3/cm3/nvic.h>
diff --git a/examples/stm32/f1/stm32vl-discovery/rtc/rtc.c b/examples/stm32/f1/stm32vl-discovery/rtc/rtc.c
index b3c698b..be40dfd 100644
--- a/examples/stm32/f1/stm32vl-discovery/rtc/rtc.c
+++ b/examples/stm32/f1/stm32vl-discovery/rtc/rtc.c
@@ -20,7 +20,7 @@
#include <libopencm3/stm32/f1/rcc.h>
#include <libopencm3/stm32/f1/gpio.h>
-#include <libopencm3/stm32/f1/rtc.h>
+#include <libopencm3/stm32/rtc.h>
#include <libopencm3/stm32/usart.h>
#include <libopencm3/stm32/pwr.h>
#include <libopencm3/cm3/nvic.h>
diff --git a/examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/Makefile b/examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/Makefile
new file mode 100644
index 0000000..d57ea7a
--- /dev/null
+++ b/examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/Makefile
@@ -0,0 +1,24 @@
+##
+## 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 = main
+LDSCRIPT = ../../../../../lib/stm32/l1/stm32l15xxb.ld
+
+include ../../Makefile.include
+
diff --git a/examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/README b/examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/README
new file mode 100644
index 0000000..83cccfc
--- /dev/null
+++ b/examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/README
@@ -0,0 +1,18 @@
+This is _functionally_ identical to the "button-irq-printf"
+example, but has been modified to use some low power features.
+
+There is a 115200@8n1 console on PA2, which prints a tick count every second,
+and when the user push button is pressed, the time it is held down for is
+timed (in milliseconds)
+
+Instead of free running timers and busy loops, this version uses the RTC
+module and attempts to sleep as much as possible, including while the button
+is pressed.
+
+Status
+~~~~~~
+Only very basic power savings are done!
+
+Current consumption, led off/on, 16Mhz HSI: 2.7mA/5.4mA
+Current consumption, led off/on, 4Mhz HSI: 1.4mA/?.?mA
+Current consumption, led off/on, 4Mhz MSI: 0.9mA/?.?mA
diff --git a/examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/main.c b/examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/main.c
new file mode 100644
index 0000000..3f19319
--- /dev/null
+++ b/examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/main.c
@@ -0,0 +1,300 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2012 Karl Palsson <karlp@tweak.net.au>
+ *
+ * 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 <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <libopencm3/cm3/nvic.h>
+#include <libopencm3/cm3/scb.h>
+#include <libopencm3/stm32/dbgmcu.h>
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/stm32/pwr.h>
+#include <libopencm3/stm32/exti.h>
+#include <libopencm3/stm32/timer.h>
+#include <libopencm3/stm32/usart.h>
+#include <libopencm3/stm32/rtc.h>
+#include <libopencm3/stm32/l1/rcc.h>
+#include <libopencm3/stm32/l1/flash.h>
+
+#include "syscfg.h"
+
+static volatile struct state_t state;
+
+__attribute__((always_inline)) static inline void __WFI(void)
+{
+ __asm volatile ("wfi");
+}
+
+void gpio_setup(void)
+{
+ /* green led for ticking, blue for button feedback */
+ gpio_mode_setup(LED_DISCO_GREEN_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, LED_DISCO_GREEN_PIN);
+ gpio_mode_setup(LED_DISCO_BLUE_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, LED_DISCO_BLUE_PIN);
+
+ /* Setup GPIO pins for USART2 transmit. */
+ gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO2);
+
+ /* Setup USART2 TX pin as alternate function. */
+ gpio_set_af(GPIOA, GPIO_AF7, GPIO2);
+}
+
+void BUTTON_DISCO_USER_isr(void)
+{
+ exti_reset_request(BUTTON_DISCO_USER_EXTI);
+ state.pressed = true;
+ if (state.falling) {
+ state.falling = false;
+ exti_set_trigger(BUTTON_DISCO_USER_EXTI, EXTI_TRIGGER_RISING);
+ state.hold_time = TIM_CNT(TIMER_BUTTON_PRESS);
+ } else {
+ state.falling = true;
+ exti_set_trigger(BUTTON_DISCO_USER_EXTI, EXTI_TRIGGER_FALLING);
+ state.hold_time = TIM_CNT(TIMER_BUTTON_PRESS) = 0;
+ }
+}
+
+void setup_buttons(void)
+{
+ /* Enable EXTI0 interrupt. */
+ nvic_enable_irq(BUTTON_DISCO_USER_NVIC);
+
+ gpio_mode_setup(BUTTON_DISCO_USER_PORT, GPIO_MODE_INPUT, GPIO_PUPD_NONE, BUTTON_DISCO_USER_PIN);
+
+ /* Configure the EXTI subsystem. */
+ exti_select_source(BUTTON_DISCO_USER_EXTI, BUTTON_DISCO_USER_PORT);
+ state.falling = false;
+ exti_set_trigger(BUTTON_DISCO_USER_EXTI, EXTI_TRIGGER_RISING);
+ exti_enable_request(BUTTON_DISCO_USER_EXTI);
+}
+
+void usart_setup(void)
+{
+ usart_set_baudrate(USART_CONSOLE, 115200);
+ usart_set_databits(USART_CONSOLE, 8);
+ usart_set_stopbits(USART_CONSOLE, USART_STOPBITS_1);
+ usart_set_mode(USART_CONSOLE, USART_MODE_TX);
+ usart_set_parity(USART_CONSOLE, USART_PARITY_NONE);
+ usart_set_flow_control(USART_CONSOLE, USART_FLOWCONTROL_NONE);
+
+ /* Finally enable the USART. */
+ usart_enable(USART_CONSOLE);
+}
+
+/**
+ * Use USART_CONSOLE as a console.
+ * @param file
+ * @param ptr
+ * @param len
+ * @return
+ */
+int _write(int file, char *ptr, int len)
+{
+ int i;
+
+ if (file == STDOUT_FILENO || file == STDERR_FILENO) {
+ for (i = 0; i < len; i++) {
+ if (ptr[i] == '\n') {
+ usart_send_blocking(USART_CONSOLE, '\r');
+ }
+ usart_send_blocking(USART_CONSOLE, ptr[i]);
+ }
+ return i;
+ }
+ errno = EIO;
+ return -1;
+}
+
+/*
+ * Free running ms timer.
+ */
+void setup_button_press_timer(void)
+{
+ timer_reset(TIMER_BUTTON_PRESS);
+ timer_set_prescaler(TIMER_BUTTON_PRESS, 3999); // 4Mhz/1000hz - 1
+ timer_set_period(TIMER_BUTTON_PRESS, 0xffff);
+ timer_enable_counter(TIMER_BUTTON_PRESS);
+}
+
+int setup_rtc(void)
+{
+ /* turn on power block to enable unlocking */
+ rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_PWREN);
+ pwr_disable_backup_domain_write_protect();
+
+ /* reset rtc */
+ RCC_CSR |= RCC_CSR_RTCRST;
+ RCC_CSR &= ~RCC_CSR_RTCRST;
+
+ /* We want to use the LSE fitted on the discovery board */
+ rcc_osc_on(LSE);
+ rcc_wait_for_osc_ready(LSE);
+
+ /* Select the LSE as rtc clock */
+ rcc_rtc_select_clock(RCC_CSR_RTCSEL_LSE);
+
+ /* ?! Stdperiph examples don't turn this on until _afterwards_ which
+ * simply doesn't work. It must be on at least to be able to configure it */
+ RCC_CSR |= RCC_CSR_RTCEN;
+
+ rtc_unlock();
+
+ /* enter init mode */
+ RTC_ISR |= RTC_ISR_INIT;
+ while ((RTC_ISR & RTC_ISR_INITF) == 0)
+ ;
+
+ /* set synch prescaler, using defaults for 1Hz out */
+ u32 sync = 255;
+ u32 async = 127;
+ rtc_set_prescaler(sync, async);
+
+ /* load time and date here if desired, and hour format */
+
+ /* exit init mode */
+ RTC_ISR &= ~(RTC_ISR_INIT);
+
+ /* and write protect again */
+ rtc_lock();
+
+ /* and finally enable the clock */
+ RCC_CSR |= RCC_CSR_RTCEN;
+
+ /* And wait for synchro.. */
+ rtc_wait_for_synchro();
+ return 0;
+}
+
+int setup_rtc_wakeup(int period)
+{
+ rtc_unlock();
+
+ /* ensure wakeup timer is off */
+ RTC_CR &= ~RTC_CR_WUTE;
+
+ /* Wait until we can write */
+ while ((RTC_ISR & RTC_ISR_WUTWF) == 0)
+ ;
+
+ RTC_WUTR = period - 1;
+
+ /* Use the 1Hz clock as source */
+ RTC_CR &= ~(RTC_CR_WUCLKSEL_MASK << RTC_CR_WUCLKSEL_SHIFT);
+ RTC_CR |= (RTC_CR_WUCLKSEL_SPRE << RTC_CR_WUCLKSEL_SHIFT);
+
+ /* Restart WakeUp unit */
+ RTC_CR |= RTC_CR_WUTE;
+
+ /* interrupt configuration */
+
+ /* also, let's have an interrupt */
+ RTC_CR |= RTC_CR_WUTIE;
+
+ /* done with rtc registers, lock them again */
+ rtc_lock();
+
+
+ nvic_enable_irq(NVIC_RTC_WKUP_IRQ);
+
+ // EXTI configuration
+ /* Configure the EXTI subsystem. */
+ // not needed, this chooses ports exti_select_source(EXTI20, BUTTON_DISCO_USER_PORT);
+ exti_set_trigger(EXTI20, EXTI_TRIGGER_RISING);
+ exti_enable_request(EXTI20);
+ return 0;
+}
+
+void rtc_wkup_isr(void)
+{
+ /* clear flag, not write protected */
+ RTC_ISR &= ~(RTC_ISR_WUTF);
+ exti_reset_request(EXTI20);
+ state.rtc_ticked = true;
+}
+
+int process_state(volatile struct state_t *st)
+{
+ if (st->rtc_ticked) {
+ st->rtc_ticked = 0;
+ printf("Tick: %x\n", (unsigned int) RTC_TR);
+#if FULL_USER_EXPERIENCE
+ gpio_toggle(LED_DISCO_GREEN_PORT, LED_DISCO_GREEN_PIN);
+#else
+ gpio_clear(LED_DISCO_GREEN_PORT, LED_DISCO_GREEN_PIN);
+#endif
+ }
+ if (st->pressed) {
+ st->pressed = false;
+ if (st->falling) {
+ gpio_set(LED_DISCO_BLUE_PORT, LED_DISCO_BLUE_PIN);
+ printf("Pushed down!\n");
+ } else {
+ gpio_clear(LED_DISCO_BLUE_PORT, LED_DISCO_BLUE_PIN);
+ printf("held: %u ms\n", st->hold_time);
+ }
+ }
+ return 0;
+}
+
+void reset_clocks(void)
+{
+ /* 4MHz MSI raw range 2*/
+ clock_scale_t myclock_config = {
+ .hpre = RCC_CFGR_HPRE_SYSCLK_NODIV,
+ .ppre1 = RCC_CFGR_PPRE1_HCLK_NODIV,
+ .ppre2 = RCC_CFGR_PPRE2_HCLK_NODIV,
+ .voltage_scale = RANGE2,
+ .flash_config = FLASH_LATENCY_0WS,
+ .apb1_frequency = 4194000,
+ .apb2_frequency = 4194000,
+ .msi_range = RCC_ICSCR_MSIRANGE_4MHZ,
+ };
+ rcc_clock_setup_msi(&myclock_config);
+
+ /* buttons and uarts */
+ rcc_peripheral_enable_clock(&RCC_AHBENR, RCC_AHBENR_GPIOAEN);
+ /* user feedback leds */
+ rcc_peripheral_enable_clock(&RCC_AHBENR, RCC_AHBENR_GPIOBEN);
+ /* Enable clocks for USART2. */
+ rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_USART2EN);
+ /* And a timers for button presses */
+ rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_TIM7EN);
+}
+
+int main(void)
+{
+ reset_clocks();
+ gpio_setup();
+ usart_setup();
+ setup_buttons();
+ setup_button_press_timer();
+ printf("we're awake!\n");
+
+ setup_rtc();
+ setup_rtc_wakeup(1);
+
+ while (1) {
+ PWR_CR |= PWR_CR_LPSDSR;
+ pwr_set_stop_mode();
+ __WFI();
+ reset_clocks();
+ process_state(&state);
+ }
+
+ return 0;
+} \ No newline at end of file
diff --git a/examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/syscfg.h b/examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/syscfg.h
new file mode 100644
index 0000000..8ca634b
--- /dev/null
+++ b/examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/syscfg.h
@@ -0,0 +1,61 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2012 Karl Palsson <karlp@tweak.net.au>
+ *
+ * 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/>.
+ */
+
+#ifndef SYSCFG_H
+#define SYSCFG_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <libopencm3/cm3/nvic.h>
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/stm32/exti.h>
+#include <libopencm3/stm32/usart.h>
+
+
+#define USART_CONSOLE USART2
+#define USE_NASTYLOG 1
+
+#define LED_DISCO_GREEN_PORT GPIOB
+#define LED_DISCO_GREEN_PIN GPIO7
+#define LED_DISCO_BLUE_PORT GPIOB
+#define LED_DISCO_BLUE_PIN GPIO6
+
+#define BUTTON_DISCO_USER_PORT GPIOA
+#define BUTTON_DISCO_USER_PIN GPIO0
+#define BUTTON_DISCO_USER_EXTI EXTI0
+#define BUTTON_DISCO_USER_isr exti0_isr
+#define BUTTON_DISCO_USER_NVIC NVIC_EXTI0_IRQ
+#define TIMER_BUTTON_PRESS TIM7
+
+ struct state_t {
+ bool falling;
+ bool pressed;
+ int rtc_ticked;
+ int hold_time;
+ };
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* SYSCFG_H */
+
diff --git a/examples/stm32/l1/stm32l-discovery/button-irq-printf/README b/examples/stm32/l1/stm32l-discovery/button-irq-printf/README
index 63232ef..5de96a2 100644
--- a/examples/stm32/l1/stm32l-discovery/button-irq-printf/README
+++ b/examples/stm32/l1/stm32l-discovery/button-irq-printf/README
@@ -1,3 +1,35 @@
* Prints to the screen when the button is pushed/released (irq driven)
115200@8n1 console on PA2 (tx only)
+* uses basic timer 6 with overflows to generate a 1ms counter (not an ideal
+ use, but shows some api methods and can be demoed on the disco board)
+* uses basic timer 7 with the exti interrupts to do ghetto input capture.
+ Not as fast or precise as the real input capture modes, but can be used
+ on any gpio pin.
+
+No effort at saving power is made here. Current consumption on the Disco board
+is ~7.5mA when the green tick led is off, and about 10.5mA when it is on.
+
+example output:
+
+hi guys!
+TICK 0
+TICK 1
+TICK 2
+Pushed down!
+held: 443 ms
+Pushed down!
+TICK 3
+held: 217 ms
+Pushed down!
+held: 99 ms
+Pushed down!
+TICK 4
+held: 73 ms
+Pushed down!
+held: 60 ms
+TICK 5
+Pushed down!
+held: 98 ms
+Pushed down!
+
diff --git a/examples/stm32/l1/stm32l-discovery/button-irq-printf/main.c b/examples/stm32/l1/stm32l-discovery/button-irq-printf/main.c
index 762fdd9..82a3434 100644
--- a/examples/stm32/l1/stm32l-discovery/button-irq-printf/main.c
+++ b/examples/stm32/l1/stm32l-discovery/button-irq-printf/main.c
@@ -22,8 +22,9 @@
#include <unistd.h>
#include <libopencm3/cm3/nvic.h>
#include <libopencm3/stm32/l1/rcc.h>
-#include <libopencm3/stm32/l1/gpio.h>
+#include <libopencm3/stm32/gpio.h>
#include <libopencm3/stm32/exti.h>
+#include <libopencm3/stm32/timer.h>
#include <libopencm3/stm32/usart.h>
#include "syscfg.h"
@@ -32,17 +33,25 @@ static struct state_t state;
void clock_setup(void)
{
+ rcc_clock_setup_pll(&clock_config[CLOCK_VRANGE1_HSI_PLL_24MHZ]);
/* Lots of things on all ports... */
rcc_peripheral_enable_clock(&RCC_AHBENR, RCC_AHBENR_GPIOAEN);
rcc_peripheral_enable_clock(&RCC_AHBENR, RCC_AHBENR_GPIOBEN);
/* Enable clocks for USART2. */
rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_USART2EN);
+
+ /* And timers. */
+ rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_TIM6EN);
+ rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_TIM7EN);
+
}
void gpio_setup(void)
{
+ /* green led for ticking, blue for button feedback */
gpio_mode_setup(LED_DISCO_GREEN_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, LED_DISCO_GREEN_PIN);
+ gpio_mode_setup(LED_DISCO_BLUE_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, LED_DISCO_BLUE_PIN);
/* Setup GPIO pins for USART2 transmit. */
gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO2);
@@ -92,18 +101,61 @@ void BUTTON_DISCO_USER_isr(void)
{
exti_reset_request(BUTTON_DISCO_USER_EXTI);
if (state.falling) {
+ gpio_clear(LED_DISCO_BLUE_PORT, LED_DISCO_BLUE_PIN);
state.falling = false;
exti_set_trigger(BUTTON_DISCO_USER_EXTI, EXTI_TRIGGER_RISING);
- // ILOG("fell: %d\n", TIM_CNT(TIM7));
- puts("fell!\n");
+ unsigned int x = TIM_CNT(TIM7);
+ printf("held: %u ms\n", x);
} else {
- puts("Rose!\n");
- // TIM_CNT(TIM7) = 0;
+ gpio_set(LED_DISCO_BLUE_PORT, LED_DISCO_BLUE_PIN);
+ printf("Pushed down!\n");
+ TIM_CNT(TIM7) = 0;
state.falling = true;
exti_set_trigger(BUTTON_DISCO_USER_EXTI, EXTI_TRIGGER_FALLING);
}
}
+static volatile int t6ovf = 0;
+
+void tim6_isr(void)
+{
+ TIM_SR(TIM6) &= ~TIM_SR_UIF;
+ if (t6ovf++ > 1000) {
+ printf("TICK %d\n", state.tickcount++);
+ t6ovf = 0;
+ gpio_toggle(LED_DISCO_GREEN_PORT, LED_DISCO_GREEN_PIN);
+ }
+}
+
+/*
+ * Another ms timer, this one used to generate an overflow interrupt at 1ms
+ * It is used to toggle leds and write tick counts
+ */
+void setup_tim6(void)
+{
+ timer_reset(TIM6);
+ // 24Mhz / 10khz -1.
+ timer_set_prescaler(TIM6, 2399); // 24Mhz/10000hz - 1
+ // 10khz for 10 ticks = 1 khz overflow = 1ms overflow interrupts
+ timer_set_period(TIM6, 10);
+
+ nvic_enable_irq(NVIC_TIM6_IRQ);
+ timer_enable_update_event(TIM6); // default at reset!
+ timer_enable_irq(TIM6, TIM_DIER_UIE);
+ timer_enable_counter(TIM6);
+}
+
+/*
+ * Free running ms timer.
+ */
+void setup_tim7(void)
+{
+ timer_reset(TIM7);
+ timer_set_prescaler(TIM7, 23999); // 24Mhz/1000hz - 1
+ timer_set_period(TIM7, 0xffff);
+ timer_enable_counter(TIM7);
+}
+
void setup_buttons(void)
{
/* Enable EXTI0 interrupt. */
@@ -120,19 +172,15 @@ void setup_buttons(void)
int main(void)
{
- int i;
- int j = 0;
clock_setup();
gpio_setup();
usart_setup();
- puts("hi guys!\n");
+ printf("hi guys!\n");
setup_buttons();
+ setup_tim6();
+ setup_tim7();
while (1) {
- puts("tick:");
- putchar('a' + (j++ % 26));
- gpio_toggle(GPIOB, GPIO7); /* LED on/off */
- for (i = 0; i < 100000; i++) /* Wait a bit. */
- __asm__("NOP");
+ ;
}
return 0;
diff --git a/examples/stm32/l1/stm32l-discovery/button-irq-printf/syscfg.h b/examples/stm32/l1/stm32l-discovery/button-irq-printf/syscfg.h
index be54502..d278ac4 100644
--- a/examples/stm32/l1/stm32l-discovery/button-irq-printf/syscfg.h
+++ b/examples/stm32/l1/stm32l-discovery/button-irq-printf/syscfg.h
@@ -24,8 +24,8 @@
extern "C" {
#endif
-#include <libopencm3/stm32/l1/gpio.h>
-#include <libopencm3/stm32/l1/nvic.h>
+#include <libopencm3/cm3/nvic.h>
+#include <libopencm3/stm32/gpio.h>
#include <libopencm3/stm32/exti.h>
#include <libopencm3/stm32/usart.h>
@@ -46,6 +46,7 @@ extern "C" {
struct state_t {
bool falling;
+ int tickcount;
};
diff --git a/include/libopencm3/stm32/l1/rcc.h b/include/libopencm3/stm32/l1/rcc.h
index a751def..4dc5102 100644
--- a/include/libopencm3/stm32/l1/rcc.h
+++ b/include/libopencm3/stm32/l1/rcc.h
@@ -444,6 +444,7 @@ void rcc_set_ppre1(u32 ppre1);
void rcc_set_hpre(u32 hpre);
void rcc_set_usbpre(u32 usbpre);
u32 rcc_get_system_clock_source(int i);
+void rcc_rtc_select_clock(u32 clock);
void rcc_clock_setup_msi(const clock_scale_t *clock);
void rcc_clock_setup_hsi(const clock_scale_t *clock);
void rcc_clock_setup_pll(const clock_scale_t *clock);
diff --git a/lib/stm32/l1/rcc.c b/lib/stm32/l1/rcc.c
index c1d8fa9..9b2df24 100644
--- a/lib/stm32/l1/rcc.c
+++ b/lib/stm32/l1/rcc.c
@@ -437,6 +437,12 @@ u32 rcc_system_clock_source(void)
return ((RCC_CFGR & 0x000c) >> 2);
}
+void rcc_rtc_select_clock(u32 clock)
+{
+ RCC_CSR &= ~(RCC_CSR_RTCSEL_MASK << RCC_CSR_RTCSEL_SHIFT);
+ RCC_CSR |= (clock << RCC_CSR_RTCSEL_SHIFT);
+}
+
void rcc_clock_setup_msi(const clock_scale_t *clock)
{
/* Enable internal multi-speed oscillator. */