From d9fb4f7401b8bf546cc7e6ddeb9f22d343f0622d Mon Sep 17 00:00:00 2001 From: Karl Palsson Date: Wed, 23 Jan 2013 00:01:46 +0000 Subject: 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. --- .../l1/stm32l-discovery/button-irq-printf/README | 32 ++++++++++ .../l1/stm32l-discovery/button-irq-printf/main.c | 74 ++++++++++++++++++---- .../l1/stm32l-discovery/button-irq-printf/syscfg.h | 5 +- 3 files changed, 96 insertions(+), 15 deletions(-) (limited to 'examples/stm32/l1/stm32l-discovery/button-irq-printf') 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 #include #include -#include +#include #include +#include #include #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 -#include +#include +#include #include #include @@ -46,6 +46,7 @@ extern "C" { struct state_t { bool falling; + int tickcount; }; -- cgit v1.2.3