Nordic stack and drivers for the mbed BLE API Modified for HRM1017 for library 0.1.0

Fork of nRF51822 by Nordic Semiconductor

Files at this revision

API Documentation at this revision

Comitter:
Rohit Grover
Date:
Tue Sep 02 16:42:56 2014 +0100
Parent:
58:de6b64cd7f21
Child:
60:e861f2041469
Commit message:
Release 0.1.1
=============

Minor bugfix release.

Bugfixes
~~~~~~~~

- drop duplicate app_timer.cpp; it's already present in the mbed SDK.
- add missing code for custom_add_in_descriptor() to custom_helper.cpp

Compatibility
~~~~~~~~~~~~~

Compatible with revision 0.1.0 of the BLE_API.

Changed in this revision

btle/custom/custom_helper.cpp Show annotated file Show diff for this revision Revisions of this file
nordic/app_common/app_timer.cpp Show diff for this revision Revisions of this file
--- a/btle/custom/custom_helper.cpp	Tue Sep 02 16:15:26 2014 +0100
+++ b/btle/custom/custom_helper.cpp	Tue Sep 02 16:42:56 2014 +0100
@@ -245,3 +245,53 @@
 
     return ERROR_NONE;
 }
+
+
+
+/**************************************************************************/
+/*!
+    @brief      Adds a new descriptor to the custom service, assigning
+                value, a UUID add-on value, etc.
+
+    @param[in]  char_handle
+    @param[in]  p_uuid            The 16-bit value to add to the base UUID
+                                  for this descriptor (normally >1
+                                  since 1 is typically used by the primary
+                                  service).
+    @param[in]  max_length        The maximum length of this descriptor
+
+    @returns
+    @retval     ERROR_NONE        Everything executed normally
+*/
+/**************************************************************************/
+error_t custom_add_in_descriptor(uint16_t    char_handle,
+                                             ble_uuid_t *p_uuid,
+                                             uint8_t    *p_data,
+                                             uint16_t    min_length,
+                                             uint16_t    max_length,
+                                             uint16_t   *p_desc_handle)
+{
+    /* Descriptor metadata */
+    ble_gatts_attr_md_t   desc_md = {0};
+
+    desc_md.vloc = BLE_GATTS_VLOC_STACK;
+    desc_md.vlen = (min_length == max_length) ? 0 : 1;
+
+    /* Make it readable and writable */
+    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&desc_md.read_perm);
+    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&desc_md.write_perm);
+
+    ble_gatts_attr_t attr_desc = {0};
+
+    attr_desc.p_uuid    = p_uuid;
+    attr_desc.p_attr_md = &desc_md;
+    attr_desc.init_len  = min_length;
+    attr_desc.max_len   = max_length;
+    attr_desc.p_value   = p_data;
+
+    ASSERT_STATUS ( sd_ble_gatts_descriptor_add(char_handle,
+                                                &attr_desc,
+                                                p_desc_handle));
+
+    return ERROR_NONE;
+}
--- a/nordic/app_common/app_timer.cpp	Tue Sep 02 16:15:26 2014 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1151 +0,0 @@
-/* Copyright (c) 2012 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.
- *
- */
-
-#include "app_timer.h"
-#include <stdlib.h>
-#include "nrf51.h"
-#include "nrf51_bitfields.h"
-#include "nrf_soc.h"
-#include "app_error.h"
-#include "nrf_delay.h"
-#include "app_util.h"
-#include "app_util_platform.h"
-
-
-#define RTC1_IRQ_PRI            APP_IRQ_PRIORITY_LOW                        /**< Priority of the RTC1 interrupt (used for checking for timeouts and executing timeout handlers). */
-#define SWI0_IRQ_PRI            APP_IRQ_PRIORITY_LOW                        /**< Priority of the SWI0 interrupt (used for updating the timer list). */
-
-// The current design assumes that both interrupt handlers run at the same interrupt level.
-// If this is to be changed, protection must be added to prevent them from interrupting each other
-// (e.g. by using guard/trigger flags).
-STATIC_ASSERT(RTC1_IRQ_PRI == SWI0_IRQ_PRI);
-
-#define APP_HIGH_USER_ID        0                                           /**< User Id for the Application High "user". */
-#define APP_LOW_USER_ID         1                                           /**< User Id for the Application Low "user". */
-#define THREAD_MODE_USER_ID     2                                           /**< User Id for the Thread Mode "user". */
-
-#define RTC_COMPARE_OFFSET_MIN  3                                           /**< Minimum offset between the current RTC counter value and the Capture Compare register. Although the nRF51 Series User Specification recommends this value to be 2, we use 3 to be safer.*/
-
-#define MAX_RTC_TASKS_DELAY     47                                          /**< Maximum delay until an RTC task is executed. */
-
-/**@brief Timer allocation state type. */
-typedef enum
-{
-    STATE_FREE,                                                             /**< The timer node is available. */
-    STATE_ALLOCATED                                                         /**< The timer node has been allocated. */
-} timer_alloc_state_t;
-
-/**@brief Timer node type. The nodes will be used form a linked list of running timers. */
-typedef struct
-{
-    timer_alloc_state_t         state;                                      /**< Timer allocation state. */
-    app_timer_mode_t            mode;                                       /**< Timer mode. */
-    uint32_t                    ticks_to_expire;                            /**< Number of ticks from previous timer interrupt to timer expiry. */
-    uint32_t                    ticks_at_start;                             /**< Current RTC counter value when the timer was started. */
-    uint32_t                    ticks_first_interval;                       /**< Number of ticks in the first timer interval. */
-    uint32_t                    ticks_periodic_interval;                    /**< Timer period (for repeating timers). */
-    bool                        is_running;                                 /**< True if timer is running, False otherwise. */
-    app_timer_timeout_handler_t p_timeout_handler;                          /**< Pointer to function to be executed when the timer expires. */
-    void *                      p_context;                                  /**< General purpose pointer. Will be passed to the timeout handler when the timer expires. */
-    app_timer_id_t              next;                                       /**< Id of next timer in list of running timers. */
-} timer_node_t;
-
-STATIC_ASSERT(sizeof(timer_node_t) <= APP_TIMER_NODE_SIZE);
-STATIC_ASSERT(sizeof(timer_node_t) % 4 == 0);
-
-/**@brief Set of available timer operation types. */
-typedef enum
-{
-    TIMER_USER_OP_TYPE_NONE,                                                /**< Invalid timer operation type. */
-    TIMER_USER_OP_TYPE_START,                                               /**< Timer operation type Start. */
-    TIMER_USER_OP_TYPE_STOP,                                                /**< Timer operation type Stop. */
-    TIMER_USER_OP_TYPE_STOP_ALL                                             /**< Timer operation type Stop All. */
-} timer_user_op_type_t;
-
-/**@brief Structure describing a timer start operation. */
-typedef struct
-{
-    uint32_t ticks_at_start;                                                /**< Current RTC counter value when the timer was started. */
-    uint32_t ticks_first_interval;                                          /**< Number of ticks in the first timer interval. */
-    uint32_t ticks_periodic_interval;                                       /**< Timer period (for repeating timers). */
-    void *   p_context;                                                     /**< General purpose pointer. Will be passed to the timeout handler when the timer expires. */
-} timer_user_op_start_t;
-
-/**@brief Structure describing a timer operation. */
-typedef struct
-{
-    timer_user_op_type_t op_type;                                           /**< Timer operation type. */
-    app_timer_id_t       timer_id;                                          /**< Id of timer on which the operation is to be performed. */
-    union
-    {
-        timer_user_op_start_t start;                                        /**< Structure describing a timer start operation. */
-    } params;
-} timer_user_op_t;
-
-STATIC_ASSERT(sizeof(timer_user_op_t) <= APP_TIMER_USER_OP_SIZE);
-STATIC_ASSERT(sizeof(timer_user_op_t) % 4 == 0);
-
-/**@brief Structure describing a timer user.
- *
- * @details For each user of the timer module, there will be a timer operations queue. This queue
- *          will hold timer operations issued by this user until the timer interrupt handler
- *          processes these operations. For the current implementation, there will be one user for
- *          each interrupt level available to the application (APP_HIGH, APP_LOW and THREAD_MODE),
- *          but the module can easily be modified to e.g. have one queue per process when using an
- *          RTOS. The purpose of the queues is to be able to have a completely lockless timer
- *          implementation.
- */
-typedef struct
-{
-    uint8_t           first;                                                    /**< Index of first entry to have been inserted in the queue (i.e. the next entry to be executed). */
-    uint8_t           last;                                                     /**< Index of last entry to have been inserted in the queue. */
-    uint8_t           user_op_queue_size;                                       /**< Queue size. */
-    timer_user_op_t * p_user_op_queue;                                          /**< Queue buffer. */
-} timer_user_t;
-
-STATIC_ASSERT(sizeof(timer_user_t) == APP_TIMER_USER_SIZE);
-STATIC_ASSERT(sizeof(timer_user_t) % 4 == 0);
-
-/**@brief User id type.
- *
- * @details In the current implementation, this will automatically be generated from the current
- *          interrupt level.
- */
-typedef uint32_t timer_user_id_t;
-
-#define CONTEXT_QUEUE_SIZE_MAX      (2)                                         /**< Timer internal elapsed ticks queue size. */
-
-static uint8_t                       m_node_array_size;                         /**< Size of timer node array. */
-static timer_node_t *                mp_nodes = NULL;                           /**< Array of timer nodes. */
-static uint8_t                       m_user_array_size;                         /**< Size of timer user array. */
-static timer_user_t *                mp_users;                                  /**< Array of timer users. */
-static app_timer_id_t                m_timer_id_head;                           /**< First timer in list of running timers. */
-static uint32_t                      m_ticks_latest;                            /**< Last known RTC counter value. */
-static uint32_t                      m_ticks_elapsed[CONTEXT_QUEUE_SIZE_MAX];   /**< Timer internal elapsed ticks queue. */
-static uint8_t                       m_ticks_elapsed_q_read_ind;                /**< Timer internal elapsed ticks queue read index. */
-static uint8_t                       m_ticks_elapsed_q_write_ind;               /**< Timer internal elapsed ticks queue write index. */
-static app_timer_evt_schedule_func_t m_evt_schedule_func;                       /**< Pointer to function for propagating timeout events to the scheduler. */
-static bool                          m_rtc1_running;                            /**< Boolean indicating if RTC1 is running. */
-static volatile uint64_t             overflowBits;                              /**< The upper 40 bits of the 64-bit value returned by cnt_get() */
-
-
-/**@brief Function for initializing the RTC1 counter.
- *
- * @param[in] prescaler   Value of the RTC1 PRESCALER register. Set to 0 for no prescaling.
- */
-static void rtc1_init(uint32_t prescaler)
-{
-    NRF_RTC1->PRESCALER = prescaler;
-    NVIC_SetPriority(RTC1_IRQn, RTC1_IRQ_PRI);
-}
-
-
-/**@brief Function for starting the RTC1 timer.
- */
-static void rtc1_start(void)
-{
-    if (m_rtc1_running) {
-        return;
-    }
-
-    NRF_RTC1->EVTENSET = RTC_EVTEN_COMPARE0_Msk;
-    NRF_RTC1->INTENSET = RTC_INTENSET_COMPARE0_Msk | RTC_INTENSET_OVRFLW_Msk;
-
-    NVIC_ClearPendingIRQ(RTC1_IRQn);
-    NVIC_EnableIRQ(RTC1_IRQn);
-
-    NRF_RTC1->TASKS_START = 1;
-    nrf_delay_us(MAX_RTC_TASKS_DELAY);
-
-    m_rtc1_running = true;
-}
-
-
-/**@brief Function for stopping the RTC1 timer.
- */
-static void rtc1_stop(void)
-{
-    if (!m_rtc1_running) {
-        return;
-    }
-
-    NVIC_DisableIRQ(RTC1_IRQn);
-
-    NRF_RTC1->EVTENCLR = RTC_EVTEN_COMPARE0_Msk;
-    NRF_RTC1->INTENCLR = RTC_INTENSET_COMPARE0_Msk | RTC_INTENSET_OVRFLW_Msk;
-
-    NRF_RTC1->TASKS_STOP = 1;
-    nrf_delay_us(MAX_RTC_TASKS_DELAY);
-
-    NRF_RTC1->TASKS_CLEAR = 1;
-    m_ticks_latest        = 0;
-    nrf_delay_us(MAX_RTC_TASKS_DELAY);
-
-    m_rtc1_running = false;
-}
-
-
-/**@brief Function for returning the current value of the RTC1 counter.
- *
- * @return     Current value of the RTC1 counter.
- */
-static __INLINE uint32_t rtc1_counter_get(void)
-{
-    return NRF_RTC1->COUNTER;
-}
-
-
-/**@brief Function for computing the difference between two RTC1 counter values.
- *
- * @return     Number of ticks elapsed from ticks_old to ticks_now.
- */
-static __INLINE uint32_t ticks_diff_get(uint32_t ticks_now, uint32_t ticks_old)
-{
-    return ((ticks_now - ticks_old) & MAX_RTC_COUNTER_VAL);
-}
-
-
-/**@brief Function for setting the RTC1 Capture Compare register 0, and enabling the corresponding
- *        event.
- *
- * @param[in] value   New value of Capture Compare register 0.
- */
-static __INLINE void rtc1_compare0_set(uint32_t value)
-{
-    NRF_RTC1->CC[0] = value;
-}
-
-
-/**@brief Function for inserting a timer in the timer list.
- *
- * @param[in]  timer_id   Id of timer to insert.
- */
-static void timer_list_insert(app_timer_id_t timer_id)
-{
-    timer_node_t * p_timer = &mp_nodes[timer_id];
-
-    if (m_timer_id_head == TIMER_NULL)
-    {
-        m_timer_id_head = timer_id;
-    }
-    else
-    {
-        if (p_timer->ticks_to_expire <= mp_nodes[m_timer_id_head].ticks_to_expire)
-        {
-            mp_nodes[m_timer_id_head].ticks_to_expire -= p_timer->ticks_to_expire;
-
-            p_timer->next   = m_timer_id_head;
-            m_timer_id_head = timer_id;
-        }
-        else
-        {
-            app_timer_id_t previous;
-            app_timer_id_t current;
-            uint32_t       ticks_to_expire;
-
-            ticks_to_expire = p_timer->ticks_to_expire;
-            previous        = m_timer_id_head;
-            current         = m_timer_id_head;
-
-            while ((current != TIMER_NULL) && (ticks_to_expire > mp_nodes[current].ticks_to_expire))
-            {
-                ticks_to_expire -= mp_nodes[current].ticks_to_expire;
-                previous         = current;
-                current          = mp_nodes[current].next;
-            }
-
-            if (current != TIMER_NULL)
-            {
-                mp_nodes[current].ticks_to_expire -= ticks_to_expire;
-            }
-
-            p_timer->ticks_to_expire = ticks_to_expire;
-            p_timer->next            = current;
-            mp_nodes[previous].next  = timer_id;
-        }
-    }
-}
-
-
-/**@brief Function for removing a timer from the timer queue.
- *
- * @param[in]  timer_id   Id of timer to remove.
- */
-static void timer_list_remove(app_timer_id_t timer_id)
-{
-    app_timer_id_t previous;
-    app_timer_id_t current;
-    uint32_t       timeout;
-
-    // Find the timer's position in timer list
-    previous = m_timer_id_head;
-    current  = previous;
-
-    while (current != TIMER_NULL)
-    {
-        if (current == timer_id)
-        {
-            break;
-        }
-        previous = current;
-        current  = mp_nodes[current].next;
-    }
-
-    // Timer not in active list
-    if (current == TIMER_NULL)
-    {
-        return;
-    }
-
-    // Timer is the first in the list
-    if (previous == current)
-    {
-        m_timer_id_head = mp_nodes[m_timer_id_head].next;
-
-        // No more timers in the list. Disable RTC1.
-        if (m_timer_id_head == TIMER_NULL)
-        {
-            rtc1_stop();
-        }
-    }
-
-    // Remaining timeout between next timeout
-    timeout = mp_nodes[current].ticks_to_expire;
-
-    // Link previous timer with next of this timer, i.e. removing the timer from list
-    mp_nodes[previous].next = mp_nodes[current].next;
-
-    // If this is not the last timer, increment the next timer by this timer timeout
-    current = mp_nodes[previous].next;
-    if (current != TIMER_NULL)
-    {
-        mp_nodes[current].ticks_to_expire += timeout;
-    }
-}
-
-
-/**@brief Function for scheduling a check for timeouts by generating a RTC1 interrupt.
- */
-static void timer_timeouts_check_sched(void)
-{
-    NVIC_SetPendingIRQ(RTC1_IRQn);
-}
-
-
-/**@brief Function for scheduling a timer list update by generating a SWI0 interrupt.
- */
-static void timer_list_handler_sched(void)
-{
-    NVIC_SetPendingIRQ(SWI0_IRQn);
-}
-
-
-/**@brief Function for executing an application timeout handler, either by calling it directly, or
- *        by passing an event to the @ref app_scheduler.
- *
- * @param[in]  p_timer   Pointer to expired timer.
- */
-static void timeout_handler_exec(timer_node_t * p_timer)
-{
-    if (m_evt_schedule_func != NULL)
-    {
-        uint32_t err_code = m_evt_schedule_func(p_timer->p_timeout_handler, p_timer->p_context);
-        APP_ERROR_CHECK(err_code);
-    }
-    else
-    {
-        p_timer->p_timeout_handler(p_timer->p_context);
-    }
-}
-
-
-/**@brief Function for checking for expired timers.
- */
-static void timer_timeouts_check(void)
-{
-    // Handle expired of timer
-    if (m_timer_id_head != TIMER_NULL)
-    {
-        app_timer_id_t  timer_id;
-        uint32_t        ticks_elapsed;
-        uint32_t        ticks_expired;
-
-        // Initialize actual elapsed ticks being consumed to 0
-        ticks_expired = 0;
-
-        // ticks_elapsed is collected here, job will use it
-        ticks_elapsed = ticks_diff_get(rtc1_counter_get(), m_ticks_latest);
-
-        // Auto variable containing the head of timers expiring
-        timer_id = m_timer_id_head;
-
-        // Expire all timers within ticks_elapsed and collect ticks_expired
-        while (timer_id != TIMER_NULL)
-        {
-            timer_node_t * p_timer;
-
-            // Auto variable for current timer node
-            p_timer = &mp_nodes[timer_id];
-
-            // Do nothing if timer did not expire
-            if (ticks_elapsed < p_timer->ticks_to_expire)
-            {
-                break;
-            }
-
-            // Decrement ticks_elapsed and collect expired ticks
-            ticks_elapsed -= p_timer->ticks_to_expire;
-            ticks_expired += p_timer->ticks_to_expire;
-
-            // Move to next timer
-            timer_id = p_timer->next;
-
-            // Execute Task
-            timeout_handler_exec(p_timer);
-        }
-
-        // Prepare to queue the ticks expired in the m_ticks_elapsed queue.
-        if (m_ticks_elapsed_q_read_ind == m_ticks_elapsed_q_write_ind)
-        {
-            // The read index of the queue is equal to the write index. This means the new
-            // value of ticks_expired should be stored at a new location in the m_ticks_elapsed
-            // queue (which is implemented as a double buffer).
-
-            // Check if there will be a queue overflow.
-            if (++m_ticks_elapsed_q_write_ind == CONTEXT_QUEUE_SIZE_MAX)
-            {
-                // There will be a queue overflow. Hence the write index should point to the start
-                // of the queue.
-                m_ticks_elapsed_q_write_ind = 0;
-            }
-        }
-
-        // Queue the ticks expired.
-        m_ticks_elapsed[m_ticks_elapsed_q_write_ind] = ticks_expired;
-
-        timer_list_handler_sched();
-    }
-}
-
-
-/**@brief Function for acquiring the number of ticks elapsed.
- *
- * @param[out] p_ticks_elapsed   Number of ticks elapsed.
- *
- * @return     TRUE if elapsed ticks was read from queue, FALSE otherwise.
- */
-static bool elapsed_ticks_acquire(uint32_t * p_ticks_elapsed)
-{
-    // Pick the elapsed value from queue
-    if (m_ticks_elapsed_q_read_ind != m_ticks_elapsed_q_write_ind)
-    {
-        // Dequeue elapsed value
-        m_ticks_elapsed_q_read_ind++;
-        if (m_ticks_elapsed_q_read_ind == CONTEXT_QUEUE_SIZE_MAX)
-        {
-            m_ticks_elapsed_q_read_ind = 0;
-        }
-
-        *p_ticks_elapsed = m_ticks_elapsed[m_ticks_elapsed_q_read_ind];
-
-        m_ticks_latest += *p_ticks_elapsed;
-        m_ticks_latest &= MAX_RTC_COUNTER_VAL;
-
-        return true;
-    }
-    else
-    {
-        // No elapsed value in queue
-        *p_ticks_elapsed = 0;
-        return false;
-    }
-}
-
-
-/**@brief Function for handling the timer list deletions.
- *
- * @return     TRUE if Capture Compare register must be updated, FALSE otherwise.
- */
-static bool list_deletions_handler(void)
-{
-    app_timer_id_t timer_id_old_head;
-    uint8_t        user_id;
-
-    // Remember the old head, so as to decide if new compare needs to be set
-    timer_id_old_head = m_timer_id_head;
-
-    user_id = m_user_array_size;
-    while (user_id--)
-    {
-        timer_user_t * p_user         = &mp_users[user_id];
-        uint8_t        user_ops_first = p_user->first;
-
-        while (user_ops_first != p_user->last)
-        {
-            timer_node_t *    p_timer;
-            timer_user_op_t * p_user_op = &p_user->p_user_op_queue[user_ops_first];
-
-            // Traverse to next operation in queue
-            user_ops_first++;
-            if (user_ops_first == p_user->user_op_queue_size)
-            {
-                user_ops_first = 0;
-            }
-
-            switch (p_user_op->op_type)
-            {
-                case TIMER_USER_OP_TYPE_STOP:
-                    // Delete node if timer is running
-                    p_timer = &mp_nodes[p_user_op->timer_id];
-                    if (p_timer->is_running)
-                    {
-                        timer_list_remove(p_user_op->timer_id);
-                        p_timer->is_running = false;
-                    }
-                    break;
-
-                case TIMER_USER_OP_TYPE_STOP_ALL:
-                    // Delete list of running timers, and mark all timers as not running
-                    while (m_timer_id_head != TIMER_NULL)
-                    {
-                        timer_node_t * p_head = &mp_nodes[m_timer_id_head];
-
-                        p_head->is_running = false;
-                        m_timer_id_head    = p_head->next;
-                    }
-                    break;
-
-                default:
-                    // No implementation needed.
-                    break;
-            }
-        }
-    }
-
-    // Detect change in head of the list
-    return (m_timer_id_head != timer_id_old_head);
-}
-
-
-/**@brief Function for updating the timer list for expired timers.
- *
- * @param[in]  ticks_elapsed         Number of elapsed ticks.
- * @param[in]  ticks_previous        Previous known value of the RTC counter.
- * @param[out] p_restart_list_head   List of repeating timers to be restarted.
- */
-static void expired_timers_handler(uint32_t         ticks_elapsed,
-                                   uint32_t         ticks_previous,
-                                   app_timer_id_t * p_restart_list_head)
-{
-    uint32_t ticks_expired = 0;
-
-    while (m_timer_id_head != TIMER_NULL)
-    {
-        timer_node_t * p_timer;
-        app_timer_id_t id_expired;
-
-        // Auto variable for current timer node
-        p_timer = &mp_nodes[m_timer_id_head];
-
-        // Do nothing if timer did not expire
-        if (ticks_elapsed < p_timer->ticks_to_expire)
-        {
-            p_timer->ticks_to_expire -= ticks_elapsed;
-            break;
-        }
-
-        // Decrement ticks_elapsed and collect expired ticks
-        ticks_elapsed -= p_timer->ticks_to_expire;
-        ticks_expired += p_timer->ticks_to_expire;
-
-        // Timer expired, set ticks_to_expire zero
-        p_timer->ticks_to_expire = 0;
-        p_timer->is_running      = false;
-
-        // Remove the expired timer from head
-        id_expired      = m_timer_id_head;
-        m_timer_id_head = p_timer->next;
-
-        // Timer will be restarted if periodic
-        if (p_timer->ticks_periodic_interval != 0)
-        {
-            p_timer->ticks_at_start       = (ticks_previous + ticks_expired) & MAX_RTC_COUNTER_VAL;
-            p_timer->ticks_first_interval = p_timer->ticks_periodic_interval;
-            p_timer->next                 = *p_restart_list_head;
-            *p_restart_list_head          = id_expired;
-        }
-    }
-}
-
-
-/**@brief Function for handling timer list insertions.
- *
- * @param[in]  p_restart_list_head   List of repeating timers to be restarted.
- *
- * @return     TRUE if Capture Compare register must be updated, FALSE otherwise.
- */
-static bool list_insertions_handler(app_timer_id_t restart_list_head)
-{
-    app_timer_id_t timer_id_old_head;
-    uint8_t        user_id;
-
-    // Remember the old head, so as to decide if new compare needs to be set
-    timer_id_old_head = m_timer_id_head;
-
-    user_id = m_user_array_size;
-    while (user_id--)
-    {
-        timer_user_t * p_user = &mp_users[user_id];
-
-        // Handle insertions of timers
-        while ((restart_list_head != TIMER_NULL) || (p_user->first != p_user->last))
-        {
-            app_timer_id_t id_start;
-            timer_node_t * p_timer;
-
-            if (restart_list_head != TIMER_NULL)
-            {
-                id_start          = restart_list_head;
-                p_timer           = &mp_nodes[id_start];
-                restart_list_head = p_timer->next;
-            }
-            else
-            {
-                timer_user_op_t * p_user_op = &p_user->p_user_op_queue[p_user->first];
-
-                p_user->first++;
-                if (p_user->first == p_user->user_op_queue_size)
-                {
-                    p_user->first = 0;
-                }
-
-                id_start = p_user_op->timer_id;
-                p_timer  = &mp_nodes[id_start];
-
-                if ((p_user_op->op_type != TIMER_USER_OP_TYPE_START) || p_timer->is_running)
-                {
-                    continue;
-                }
-
-                p_timer->ticks_at_start          = p_user_op->params.start.ticks_at_start;
-                p_timer->ticks_first_interval    = p_user_op->params.start.ticks_first_interval;
-                p_timer->ticks_periodic_interval = p_user_op->params.start.ticks_periodic_interval;
-                p_timer->p_context               = p_user_op->params.start.p_context;
-            }
-
-            // Prepare the node to be inserted
-            if (
-                 ((p_timer->ticks_at_start - m_ticks_latest) & MAX_RTC_COUNTER_VAL)
-                 <
-                 (MAX_RTC_COUNTER_VAL / 2)
-                )
-            {
-                p_timer->ticks_to_expire = ticks_diff_get(p_timer->ticks_at_start, m_ticks_latest) +
-                                           p_timer->ticks_first_interval;
-            }
-            else
-            {
-                uint32_t delta_current_start;
-
-                delta_current_start = ticks_diff_get(m_ticks_latest, p_timer->ticks_at_start);
-                if (p_timer->ticks_first_interval > delta_current_start)
-                {
-                    p_timer->ticks_to_expire = p_timer->ticks_first_interval - delta_current_start;
-                }
-                else
-                {
-                    p_timer->ticks_to_expire = 0;
-                }
-            }
-
-            p_timer->ticks_at_start       = 0;
-            p_timer->ticks_first_interval = 0;
-            p_timer->is_running           = true;
-            p_timer->next                 = TIMER_NULL;
-
-            // Insert into list
-            timer_list_insert(id_start);
-        }
-    }
-
-    return (m_timer_id_head != timer_id_old_head);
-}
-
-
-/**@brief Function for updating the Capture Compare register.
- */
-static void compare_reg_update(app_timer_id_t timer_id_head_old)
-{
-    // Setup the timeout for timers on the head of the list
-    if (m_timer_id_head != TIMER_NULL)
-    {
-        uint32_t ticks_to_expire = mp_nodes[m_timer_id_head].ticks_to_expire;
-        uint32_t pre_counter_val = rtc1_counter_get();
-        uint32_t cc              = m_ticks_latest;
-        uint32_t ticks_elapsed   = ticks_diff_get(pre_counter_val, cc) + RTC_COMPARE_OFFSET_MIN;
-
-        if (!m_rtc1_running)
-        {
-            // No timers were already running, start RTC
-            rtc1_start();
-        }
-
-        cc += (ticks_elapsed < ticks_to_expire) ? ticks_to_expire : ticks_elapsed;
-        cc &= MAX_RTC_COUNTER_VAL;
-
-        rtc1_compare0_set(cc);
-
-        uint32_t post_counter_val = rtc1_counter_get();
-
-        if ((ticks_diff_get(post_counter_val, pre_counter_val) + RTC_COMPARE_OFFSET_MIN) > ticks_diff_get(cc, pre_counter_val))
-        {
-            // When this happens the COMPARE event may not be triggered by the RTC.
-            // The nRF51 Series User Specification states that if the COUNTER value is N
-            // (i.e post_counter_val = N), writing N or N+1 to a CC register may not trigger a
-            // COMPARE event. Hence the RTC interrupt is forcefully pended by calling the following
-            // function.
-            timer_timeouts_check_sched();
-        }
-    }
-    else
-    {
-        // No timers are running, stop RTC
-        rtc1_stop();
-    }
-}
-
-
-/**@brief Function for handling changes to the timer list.
- */
-static void timer_list_handler(void)
-{
-    app_timer_id_t restart_list_head = TIMER_NULL;
-    uint32_t       ticks_elapsed;
-    uint32_t       ticks_previous;
-    bool           ticks_have_elapsed;
-    bool           compare_update;
-    app_timer_id_t timer_id_head_old;
-
-    // Back up the previous known tick and previous list head
-    ticks_previous    = m_ticks_latest;
-    timer_id_head_old = m_timer_id_head;
-
-    // Get number of elapsed ticks
-    ticks_have_elapsed = elapsed_ticks_acquire(&ticks_elapsed);
-
-    // Handle list deletions
-    compare_update = list_deletions_handler();
-
-    // Handle expired timers
-    if (ticks_have_elapsed)
-    {
-        expired_timers_handler(ticks_elapsed, ticks_previous, &restart_list_head);
-        compare_update = true;
-    }
-
-    // Handle list insertions
-    if (list_insertions_handler(restart_list_head))
-    {
-        compare_update = true;
-    }
-
-    // Update compare register if necessary
-    if (compare_update)
-    {
-        compare_reg_update(timer_id_head_old);
-    }
-}
-
-
-/**@brief Function for enqueueing a new operations queue entry.
- *
- * @param[in]  p_user     User that the entry is to be enqueued for.
- * @param[in]  last_index Index of the next last index to be enqueued.
- */
-static void user_op_enque(timer_user_t * p_user, app_timer_id_t last_index)
-{
-    p_user->last = last_index;
-}
-
-
-/**@brief Function for allocating a new operations queue entry.
- *
- * @param[in]  p_user       User that the entry is to be allocated for.
- * @param[out] p_last_index Index of the next last index to be enqueued.
- *
- * @return     Pointer to allocated queue entry, or NULL if queue is full.
- */
-static timer_user_op_t * user_op_alloc(timer_user_t * p_user, app_timer_id_t * p_last_index)
-{
-    app_timer_id_t    last;
-    timer_user_op_t * p_user_op;
-
-    last = p_user->last + 1;
-    if (last == p_user->user_op_queue_size)
-    {
-        // Overflow case.
-        last = 0;
-    }
-    if (last == p_user->first)
-    {
-        // Queue is full.
-        return NULL;
-    }
-
-    *p_last_index = last;
-    p_user_op     = &p_user->p_user_op_queue[p_user->last];
-
-    return p_user_op;
-}
-
-
-/**@brief Function for scheduling a Timer Start operation.
- *
- * @param[in]  user_id           Id of user calling this function.
- * @param[in]  timer_id          Id of timer to start.
- * @param[in]  timeout_initial   Time (in ticks) to first timer expiry.
- * @param[in]  timeout_periodic  Time (in ticks) between periodic expiries.
- * @param[in]  p_context         General purpose pointer. Will be passed to the timeout handler when
- *                               the timer expires.
- * @return     NRF_SUCCESS on success, otherwise an error code.
- */
-static uint32_t timer_start_op_schedule(timer_user_id_t user_id,
-                                        app_timer_id_t  timer_id,
-                                        uint32_t        timeout_initial,
-                                        uint32_t        timeout_periodic,
-                                        void *          p_context)
-{
-    app_timer_id_t last_index;
-
-    timer_user_op_t * p_user_op = user_op_alloc(&mp_users[user_id], &last_index);
-    if (p_user_op == NULL)
-    {
-        return NRF_ERROR_NO_MEM;
-    }
-
-    p_user_op->op_type                              = TIMER_USER_OP_TYPE_START;
-    p_user_op->timer_id                             = timer_id;
-    p_user_op->params.start.ticks_at_start          = rtc1_counter_get();
-    p_user_op->params.start.ticks_first_interval    = timeout_initial;
-    p_user_op->params.start.ticks_periodic_interval = timeout_periodic;
-    p_user_op->params.start.p_context               = p_context;
-
-    user_op_enque(&mp_users[user_id], last_index);
-
-    timer_list_handler_sched();
-
-    return NRF_SUCCESS;
-}
-
-
-/**@brief Function for scheduling a Timer Stop operation.
- *
- * @param[in]  user_id    Id of user calling this function.
- * @param[in]  timer_id   Id of timer to stop.
- *
- * @return NRF_SUCCESS on successful scheduling a timer stop operation. NRF_ERROR_NO_MEM when there
- *         is no memory left to schedule the timer stop operation.
- */
-static uint32_t timer_stop_op_schedule(timer_user_id_t user_id, app_timer_id_t timer_id)
-{
-    app_timer_id_t last_index;
-
-    timer_user_op_t * p_user_op = user_op_alloc(&mp_users[user_id], &last_index);
-    if (p_user_op == NULL)
-    {
-        return NRF_ERROR_NO_MEM;
-    }
-
-    p_user_op->op_type  = TIMER_USER_OP_TYPE_STOP;
-    p_user_op->timer_id = timer_id;
-
-    user_op_enque(&mp_users[user_id], last_index);
-
-    timer_list_handler_sched();
-
-    return NRF_SUCCESS;
-}
-
-
-/**@brief Function for scheduling a Timer Stop All operation.
- *
- * @param[in]  user_id    Id of user calling this function.
- */
-static uint32_t timer_stop_all_op_schedule(timer_user_id_t user_id)
-{
-    app_timer_id_t last_index;
-
-    timer_user_op_t * p_user_op = user_op_alloc(&mp_users[user_id], &last_index);
-    if (p_user_op == NULL)
-    {
-        return NRF_ERROR_NO_MEM;
-    }
-
-    p_user_op->op_type  = TIMER_USER_OP_TYPE_STOP_ALL;
-    p_user_op->timer_id = TIMER_NULL;
-
-    user_op_enque(&mp_users[user_id], last_index);
-
-    timer_list_handler_sched();
-
-    return NRF_SUCCESS;
-}
-
-
-/**@brief Function for handling the RTC1 interrupt.
- *
- * @details Checks for timeouts, and executes timeout handlers for expired timers.
- */
-extern "C" void RTC1_IRQHandler(void)
-{
-    // Clear all events (also unexpected ones)
-    NRF_RTC1->EVENTS_COMPARE[0] = 0;
-    NRF_RTC1->EVENTS_COMPARE[1] = 0;
-    NRF_RTC1->EVENTS_COMPARE[2] = 0;
-    NRF_RTC1->EVENTS_COMPARE[3] = 0;
-    NRF_RTC1->EVENTS_TICK       = 0;
-    if (NRF_RTC1->EVENTS_OVRFLW) {
-        overflowBits += (1 << 24);
-    }
-    NRF_RTC1->EVENTS_OVRFLW     = 0;
-
-    // Check for expired timers
-    timer_timeouts_check();
-}
-
-/**@brief Function for handling the SWI0 interrupt.
- *
- * @details Performs all updates to the timer list.
- */
-extern "C" void SWI0_IRQHandler(void)
-{
-    timer_list_handler();
-}
-
-uint32_t app_timer_init(uint32_t                      prescaler,
-                        uint8_t                       max_timers,
-                        uint8_t                       op_queues_size,
-                        void *                        p_buffer,
-                        app_timer_evt_schedule_func_t evt_schedule_func)
-{
-    int i;
-
-    // Check that buffer is correctly aligned
-    if (!is_word_aligned(p_buffer))
-    {
-        return NRF_ERROR_INVALID_PARAM;
-    }
-    // Check for NULL buffer
-    if (p_buffer == NULL)
-    {
-        return NRF_ERROR_INVALID_PARAM;
-    }
-
-    // Stop RTC to prevent any running timers from expiring (in case of reinitialization)
-    rtc1_stop();
-
-    m_evt_schedule_func = evt_schedule_func;
-
-    // Initialize timer node array
-    m_node_array_size = max_timers;
-    mp_nodes          = (timer_node_t *) p_buffer;
-
-    for (i = 0; i < max_timers; i++)
-    {
-        mp_nodes[i].state      = STATE_FREE;
-        mp_nodes[i].is_running = false;
-    }
-
-    // Skip timer node array
-    p_buffer = &((uint8_t *)p_buffer)[max_timers * sizeof(timer_node_t)];
-
-    // Initialize users array
-    m_user_array_size = APP_TIMER_INT_LEVELS;
-    mp_users          = (timer_user_t *) p_buffer;
-
-    // Skip user array
-    p_buffer = &((uint8_t *)p_buffer)[APP_TIMER_INT_LEVELS * sizeof(timer_user_t)];
-
-    // Initialize operation queues
-    for (i = 0; i < APP_TIMER_INT_LEVELS; i++)
-    {
-        timer_user_t * p_user = &mp_users[i];
-
-        p_user->first              = 0;
-        p_user->last               = 0;
-        p_user->user_op_queue_size = op_queues_size;
-        p_user->p_user_op_queue    = (timer_user_op_t *) p_buffer;
-
-        // Skip operation queue
-        p_buffer = &((uint8_t *)p_buffer)[op_queues_size * sizeof(timer_user_op_t)];
-    }
-
-    m_timer_id_head             = TIMER_NULL;
-    m_ticks_elapsed_q_read_ind  = 0;
-    m_ticks_elapsed_q_write_ind = 0;
-
-    NVIC_ClearPendingIRQ(SWI0_IRQn);
-    NVIC_SetPriority(SWI0_IRQn, SWI0_IRQ_PRI);
-    NVIC_EnableIRQ(SWI0_IRQn);
-
-    rtc1_init(prescaler);
-    rtc1_start();
-
-    m_ticks_latest = rtc1_counter_get();
-
-    return NRF_SUCCESS;
-}
-
-
-uint32_t app_timer_create(app_timer_id_t *            p_timer_id,
-                          app_timer_mode_t            mode,
-                          app_timer_timeout_handler_t timeout_handler)
-{
-    int i;
-
-    // Check state and parameters
-    if (mp_nodes == NULL)
-    {
-        return NRF_ERROR_INVALID_STATE;
-    }
-    if (timeout_handler == NULL)
-    {
-        return NRF_ERROR_INVALID_PARAM;
-    }
-    if (p_timer_id == NULL)
-    {
-        return NRF_ERROR_INVALID_PARAM;
-    }
-
-    // Find free timer
-    for (i = 0; i < m_node_array_size; i++)
-    {
-        if (mp_nodes[i].state == STATE_FREE)
-        {
-            mp_nodes[i].state             = STATE_ALLOCATED;
-            mp_nodes[i].mode              = mode;
-            mp_nodes[i].p_timeout_handler = timeout_handler;
-
-            *p_timer_id = i;
-            return NRF_SUCCESS;
-        }
-    }
-
-    return NRF_ERROR_NO_MEM;
-}
-
-
-/**@brief Function for creating a timer user id from the current interrupt level.
- *
- * @return     Timer user id.
-*/
-static timer_user_id_t user_id_get(void)
-{
-    timer_user_id_t ret;
-
-    STATIC_ASSERT(APP_TIMER_INT_LEVELS == 3);
-
-    switch (current_int_priority_get())
-    {
-        case APP_IRQ_PRIORITY_HIGH:
-            ret = APP_HIGH_USER_ID;
-            break;
-
-        case APP_IRQ_PRIORITY_LOW:
-            ret = APP_LOW_USER_ID;
-            break;
-
-        default:
-            ret = THREAD_MODE_USER_ID;
-            break;
-    }
-
-    return ret;
-}
-
-
-uint32_t app_timer_start(app_timer_id_t timer_id, uint32_t timeout_ticks, void * p_context)
-{
-    uint32_t timeout_periodic;
-
-    // Check state and parameters
-    if (mp_nodes == NULL)
-    {
-        return NRF_ERROR_INVALID_STATE;
-    }
-    if ((timer_id >= m_node_array_size) || (timeout_ticks < APP_TIMER_MIN_TIMEOUT_TICKS))
-    {
-        return NRF_ERROR_INVALID_PARAM;
-    }
-    if (mp_nodes[timer_id].state != STATE_ALLOCATED)
-    {
-        return NRF_ERROR_INVALID_STATE;
-    }
-
-    // Schedule timer start operation
-    timeout_periodic = (mp_nodes[timer_id].mode == APP_TIMER_MODE_REPEATED) ? timeout_ticks : 0;
-
-    return timer_start_op_schedule(user_id_get(),
-                                   timer_id,
-                                   timeout_ticks,
-                                   timeout_periodic,
-                                   p_context);
-}
-
-
-uint32_t app_timer_stop(app_timer_id_t timer_id)
-{
-    // Check state and parameters
-    if (mp_nodes == NULL)
-    {
-        return NRF_ERROR_INVALID_STATE;
-    }
-    if (timer_id >= m_node_array_size)
-    {
-        return NRF_ERROR_INVALID_PARAM;
-    }
-    if (mp_nodes[timer_id].state != STATE_ALLOCATED)
-    {
-        return NRF_ERROR_INVALID_STATE;
-    }
-
-    // Schedule timer stop operation
-    return timer_stop_op_schedule(user_id_get(), timer_id);
-}
-
-
-uint32_t app_timer_stop_all(void)
-{
-    // Check state
-    if (mp_nodes == NULL)
-    {
-        return NRF_ERROR_INVALID_STATE;
-    }
-
-    return timer_stop_all_op_schedule(user_id_get());
-}
-
-
-uint32_t app_timer_cnt_get(uint64_t * p_ticks)
-{
-    *p_ticks = overflowBits | rtc1_counter_get();
-    return NRF_SUCCESS;
-}
-
-
-uint32_t app_timer_cnt_diff_compute(uint32_t   ticks_to,
-                                    uint32_t   ticks_from,
-                                    uint32_t * p_ticks_diff)
-{
-    *p_ticks_diff = ticks_diff_get(ticks_to, ticks_from);
-    return NRF_SUCCESS;
-}