Dear all,
I just writing a little piece of code (no softdevice, using sdk 17.00), that in theory toggle a led based on 2 compare (CC[0] and CC[1]).
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/** @file
* @defgroup nrf_dev_timer_example_main main.c
* @{
* @ingroup nrf_dev_timer_example
* @brief Timer Example Application main file.
*
* This file contains the source code for a sample application using Timer0.
*
*/
#include <stdbool.h>
#include <stdint.h>
#include "nrf.h"
#include "nrf_drv_timer.h"
#include "bsp.h"
#include "app_error.h"
// Mettendo lo 0 nella macro, sto settando il compare = 0
const nrf_drv_timer_t TIMER_LED = NRF_DRV_TIMER_INSTANCE(4);
const nrf_drv_timer_t TIMER_TIMESTAMP = NRF_DRV_TIMER_INSTANCE(2);
void timer_led_event_handler(nrf_timer_event_t event_type, void* p_context)
{
switch(event_type)
{
case NRF_TIMER_EVENT_COMPARE0:
TIMER_TIMESTAMP.p_reg->TASKS_CAPTURE[0] = 1;
printf("ON: %d\n", TIMER_TIMESTAMP.p_reg->CC[0]);
bsp_board_led_on(BSP_BOARD_LED_0);
break;
case NRF_TIMER_EVENT_COMPARE1:
TIMER_TIMESTAMP.p_reg->TASKS_CAPTURE[0] = 1;
printf("OFF: %d\n", TIMER_TIMESTAMP.p_reg->CC[0]);
bsp_board_led_off(BSP_BOARD_LED_0);
TIMER_LED.p_reg->TASKS_STOP = 1;
break;
}
}
void timer_timestamp_event_handler(nrf_timer_event_t event_type, void* p_context)
{
}
static void timer_init()
{
ret_code_t err_code;
nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;
timer_cfg.bit_width = NRF_TIMER_BIT_WIDTH_8;
timer_cfg.frequency = NRF_TIMER_FREQ_31250Hz;
err_code = nrf_drv_timer_init(&TIMER_LED, &timer_cfg, timer_led_event_handler);
APP_ERROR_CHECK(err_code);
// Setting compare
TIMER_LED.p_reg->CC[0] = 10; // 320 us
TIMER_LED.p_reg->INTENSET = 0x1UL << 16UL;
TIMER_LED.p_reg->CC[1] = 40; //1280 us
TIMER_LED.p_reg->INTENSET = 0x1UL << 16UL+1;
// Timer timestamp
timer_cfg.bit_width = NRF_TIMER_BIT_WIDTH_32;
timer_cfg.frequency = NRF_TIMER_FREQ_1MHz;
err_code = nrf_drv_timer_init(&TIMER_TIMESTAMP, &timer_cfg, timer_timestamp_event_handler);
APP_ERROR_CHECK(err_code);
// Starting timer
TIMER_TIMESTAMP.p_reg->TASKS_START = 1;
TIMER_LED.p_reg->TASKS_START = 1;
}
int main(void)
{
bsp_board_init(BSP_INIT_LEDS);
timer_init();
while (1)
{
__WFI();
}
}
/** @} */
The strange thing is that, if the 2 compare are pretty high (1 second or more) there is no problem, while if the values are low, something strange happened:
1) Why isn't the timer stopped instantly? (but it needs two cycles)
2) Why are the timestamps not correct? (I expected that OFF - ON = 960)
Thanks to everyone,
Elia
