Timer with two compared values

[acha]

Hello all,

I try to trigger two events with two different periods, the first at 200ms, the second at 300ms. When I set the same period for the compared value, it works correctly, but when I set differents periods (respectively 200 and 300 ms) it didn't work. Bellow my code :

/* Copyright (c) 2014 Nordic Semiconductor. All Rights Reserved.
 *
 * The information contained herein is property of Nordic Semiconductor ASA.
 * Terms and conditions of usage are described in detail in NORDIC
 * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT.
 *
 * Licensees are granted free, non-transferable use of the information. NO
 * WARRANTY of ANY KIND is provided. This heading must NOT be removed from
 * the file.
 *
 */

/** @file
*
* @defgroup gpiote_example_main main.c
* @{
* @ingroup nrf_gpiote_example
* @brief GPIOTE Example Application main file.
*
* This file contains the source code for a sample application using GPIOTE.
*/

#include <stdbool.h>
#include <stdint.h>
#include "nrf.h"
#include "nrf_gpiote.h"
#include "nrf_gpio.h"
#include "boards.h"
#include "nrf_drv_ppi.h"
#include "nrf_drv_timer.h"
#include "nrf_drv_gpiote.h"
#include "app_error.h"

#ifdef BSP_LED_0
    #define GPIO_OUTPUT_PIN_NUMBER BSP_LED_0  /**< Pin number for output. */
#endif
#ifndef GPIO_OUTPUT_PIN_NUMBER
    #error "Please indicate output pin"
#endif

#define PERIOD_0 200
#define PERIOD_1 300

static nrf_drv_timer_t timer = NRF_DRV_TIMER_INSTANCE(0);

void timer_dummy_handler(nrf_timer_event_t event_type, void * p_context)
{
      uint32_t compare_evt_addr_0, compare_evt_addr_1;
      uint32_t gpiote_task_addr_0, gpiote_task_addr_1;
      nrf_ppi_channel_t ppi_channel_0, ppi_channel_1;
      ret_code_t err_code;
      err_code = nrf_drv_ppi_channel_alloc(&ppi_channel_0);
      APP_ERROR_CHECK(err_code);
      err_code = nrf_drv_ppi_channel_alloc(&ppi_channel_1);
      APP_ERROR_CHECK(err_code);

      compare_evt_addr_0 = nrf_drv_timer_event_address_get(&timer, NRF_TIMER_EVENT_COMPARE0);
      gpiote_task_addr_0 = nrf_drv_gpiote_out_task_addr_get(BSP_LED_0);

      compare_evt_addr_1 = nrf_drv_timer_event_address_get(&timer, NRF_TIMER_EVENT_COMPARE1);
      gpiote_task_addr_1 = nrf_drv_gpiote_out_task_addr_get(BSP_LED_1);

      err_code = nrf_drv_ppi_channel_enable(ppi_channel_0);
      APP_ERROR_CHECK(err_code);

      err_code = nrf_drv_ppi_channel_enable(ppi_channel_1);
      APP_ERROR_CHECK(err_code);
switch (event_type)
      {
        case NRF_TIMER_EVENT_COMPARE0:
        err_code = nrf_drv_ppi_channel_assign(ppi_channel_0, compare_evt_addr_0, gpiote_task_addr_0);
        APP_ERROR_CHECK(err_code);
        break;

        case NRF_TIMER_EVENT_COMPARE1:
          err_code = nrf_drv_ppi_channel_assign(ppi_channel_1, compare_evt_addr_1, gpiote_task_addr_1);
          APP_ERROR_CHECK(err_code);
        break;

        default:
        break;

      }
}

static void led_blinking_setup()
{

    ret_code_t err_code;
    nrf_drv_gpiote_out_config_t config = GPIOTE_CONFIG_OUT_TASK_TOGGLE(false);

    err_code = nrf_drv_gpiote_out_init(BSP_LED_0, &config);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_gpiote_out_init(BSP_LED_1, &config);
    APP_ERROR_CHECK(err_code);

    nrf_drv_timer_extended_compare(&timer, (nrf_timer_cc_channel_t)0, PERIOD_0 * 1000UL, NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK, true);
    nrf_drv_timer_extended_compare(&timer, NRF_TIMER_CC_CHANNEL1, PERIOD_1 * 1000UL, NRF_TIMER_SHORT_COMPARE1_CLEAR_MASK, true);


    nrf_drv_gpiote_out_task_enable(BSP_LED_0);
    nrf_drv_gpiote_out_task_enable(BSP_LED_1);
}

/**
 * @brief Function for application main entry.
 */
int main(void)
{
    ret_code_t err_code;

    err_code = nrf_drv_ppi_init();
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_gpiote_init();
    APP_ERROR_CHECK(err_code);

    nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;

    err_code = nrf_drv_timer_init(&timer, &timer_cfg, timer_dummy_handler);
    APP_ERROR_CHECK(err_code);
#ifdef NRF51
    //Workaround for PAN-73.
    *(uint32_t *)0x40008C0C = 1;
#endif

    // Setup PPI channel with event from TIMER compare and task GPIOTE pin toggle.
    led_blinking_setup();

    // Enable timer
    nrf_drv_timer_enable(&timer);

    while (true)
    {
        // Do Nothing - GPIO can be toggled without software intervention.
    }
}


/** @} */

[acha]

thank you so much for your help. It works, but for my basic application, I dont want to use ppi, it was only for debug, so now, i try to implement a simple program using timer and 3 compare events with different period (respectively 200, 300 and 400 ms), without using ppi (of corse). So, I implement this program which didn't work, and the events are triggered at the maximal period of these setted for each event (400 ms in my case). Bellow my code :

/* Copyright (c) 2014 Nordic Semiconductor. All Rights Reserved.
 *
 * The information contained herein is property of Nordic Semiconductor ASA.
 * Terms and conditions of usage are described in detail in NORDIC
 * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT.
 *
 * Licensees are granted free, non-transferable use of the information. NO
 * WARRANTY of ANY KIND is provided. This heading must NOT be removed from
 * the file.
 *
 */

/** @file
*
* @defgroup gpiote_example_main main.c
* @{
* @ingroup nrf_gpiote_example
* @brief GPIOTE Example Application main file.
*
* This file contains the source code for a sample application using GPIOTE.
*/

#include <stdbool.h>
#include <stdint.h>
#include "nrf.h"
#include "nrf_gpiote.h"
#include "nrf_gpio.h"
#include "boards.h"
#include "nrf_drv_ppi.h"
#include "nrf_drv_timer.h"
#include "nrf_drv_gpiote.h"
#include "app_error.h"

#define PERIOD_0 200
#define PERIOD_1 300
#define PERIOD_2 400

static nrf_drv_timer_t timer = NRF_DRV_TIMER_INSTANCE(0);

void timer_dummy_handler(nrf_timer_event_t event_type, void * p_context)
{
  if (event_type==NRF_TIMER_EVENT_COMPARE0)
  {
          nrf_drv_gpiote_out_toggle(BSP_LED_0);
  }

  if (event_type==NRF_TIMER_EVENT_COMPARE1)
  {
          nrf_drv_gpiote_out_toggle(BSP_LED_1);
  }

  if (event_type==NRF_TIMER_EVENT_COMPARE2)
  {
          nrf_drv_gpiote_out_toggle(BSP_LED_2);
  }
}

static void led_blinking_setup()
{

    ret_code_t err_code;

    nrf_drv_gpiote_out_config_t out_config = GPIOTE_CONFIG_OUT_SIMPLE(false);

    err_code = nrf_drv_gpiote_out_init(BSP_LED_0, &out_config);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_gpiote_out_init(BSP_LED_1, &out_config);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_gpiote_out_init(BSP_LED_2, &out_config);
    APP_ERROR_CHECK(err_code);

    nrf_drv_timer_compare(&timer, NRF_TIMER_CC_CHANNEL0, PERIOD_0 * 1000UL, true);
    nrf_drv_timer_compare(&timer, NRF_TIMER_CC_CHANNEL1, PERIOD_1 * 1000UL, true);
    nrf_drv_timer_extended_compare(&timer, NRF_TIMER_CC_CHANNEL2, PERIOD_2 * 1000UL, NRF_TIMER_SHORT_COMPARE2_CLEAR_MASK, true);

}

/**
 * @brief Function for application main entry.
 */
int main(void)
{
    ret_code_t err_code;

    err_code = nrf_drv_ppi_init();
    APP_ERROR_CHECK(err_code);

    err_code = nrf_drv_gpiote_init();
    APP_ERROR_CHECK(err_code);

    nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;
    err_code = nrf_drv_timer_init(&timer, &timer_cfg, timer_dummy_handler);
    APP_ERROR_CHECK(err_code);
#ifdef NRF51
    //Workaround for PAN-73.
    *(uint32_t *)0x40008C0C = 1;
#endif

    // Setup PPI channel with event from TIMER compare and task GPIOTE pin toggle.
    led_blinking_setup();

    // Enable timer
    nrf_drv_timer_enable(&timer);

    while (true)
    {
        // Do Nothing - GPIO can be toggled without software intervention.
    }
}


/** @} */

[Jørgen Holmefjord]

Then I would rather recommend that you take a look at the application timer library. There is a great tutorial to get you started here at DevZone. The application timer library use RTC instead of timers, making it more low-power. Only 1 RTC is used. I have created an example that use three different periods: app_timer_three_periods.c