diff options
| -rw-r--r-- | src/demo.c | 44 |
1 files changed, 38 insertions, 6 deletions
@@ -39,6 +39,7 @@ #include <string.h>
#include <stdlib.h>
+
static inline void delay_ms_busy_loop(uint32_t ms)
{
volatile uint32_t i;
@@ -61,6 +62,29 @@ static void clock_setup(void) rcc_periph_clock_enable(RCC_USART6); // USART
rcc_periph_clock_enable(RCC_OTGFS); // OTG_FS
rcc_periph_clock_enable(RCC_OTGHS); // OTG_HS
+ rcc_periph_clock_enable(RCC_TIM6); // TIM6
+}
+
+
+/*
+ * setup 10kHz timer
+ */
+static void tim6_setup(void)
+{
+ timer_reset(TIM6);
+ timer_set_prescaler(TIM6, 16800 - 1); // 168Mhz/10000hz - 1
+ timer_set_period(TIM6, 65535); // Overflow in ~6.5 seconds
+ timer_enable_counter(TIM6);
+}
+
+static uint32_t tim6_get_time_us(void)
+{
+ uint32_t cnt = timer_get_counter(TIM6);
+
+ // convert to 1MHz less precise timer value -> units: microseconds
+ uint32_t time_us = cnt * 100;
+
+ return time_us;
}
static void gpio_setup(void)
@@ -140,6 +164,9 @@ int main(void) clock_setup();
gpio_setup();
+ // provides time_curr_us to usbh_poll function
+ tim6_setup();
+
#ifdef USART_DEBUG
usart_init(USART6, 921600);
#endif
@@ -168,18 +195,23 @@ int main(void) LOG_PRINTF("USB init complete\r\n");
- uint32_t i = 0;
+ LOG_FLUSH();
while (1) {
- LOG_FLUSH();
-
- // Toggle some led
+ // set busy led
gpio_set(GPIOD, GPIO14);
- usbh_poll(i);
+
+ uint32_t time_curr_us = tim6_get_time_us();
+
+ usbh_poll(time_curr_us);
+
+ // clear busy led
gpio_clear(GPIOD, GPIO14);
+ LOG_FLUSH();
+
+ // approx 1ms interval between usbh_poll()
delay_ms_busy_loop(1);
- i += 1000;
}
return 0;
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