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/* 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.
*
*/
/** @file
*
* @defgroup app_util Utility Functions and Definitions
* @{
* @ingroup app_common
*
* @brief Various types and definitions available to all applications.
*/
#ifndef APP_UTIL_H__
#define APP_UTIL_H__
#include <stdint.h>
#include <stdbool.h>
#include "compiler_abstraction.h"
enum
{
UNIT_0_625_MS = 625, /**< Number of microseconds in 0.625 milliseconds. */
UNIT_1_25_MS = 1250, /**< Number of microseconds in 1.25 milliseconds. */
UNIT_10_MS = 10000 /**< Number of microseconds in 10 milliseconds. */
};
/**@brief Macro for doing static (i.e. compile time) assertion.
*
* @note If the assertion fails when compiling using Keil, the compiler will report error message
* "error: #94: the size of an array must be greater than zero" (while gcc will list the
* symbol static_assert_failed, making the error message more readable).
* If the supplied expression can not be evaluated at compile time, Keil will report
* "error: #28: expression must have a constant value".
*
* @note The macro is intentionally implemented not using do while(0), allowing it to be used
* outside function blocks (e.g. close to global type- and variable declarations).
* If used in a code block, it must be used before any executable code in this block.
*
* @param[in] EXPR Constant expression to be verified.
*/
#if defined(__GNUC__)
#define STATIC_ASSERT(EXPR) typedef char __attribute__((unused)) static_assert_failed[(EXPR) ? 1 : -1]
#elif defined(__ICCARM__)
#define STATIC_ASSERT(EXPR) extern char static_assert_failed[(EXPR) ? 1 : -1]
#else
#define STATIC_ASSERT(EXPR) typedef char static_assert_failed[(EXPR) ? 1 : -1]
#endif
/**@brief type for holding an encoded (i.e. little endian) 16 bit unsigned integer. */
typedef uint8_t uint16_le_t[2];
/**@brief type for holding an encoded (i.e. little endian) 32 bit unsigned integer. */
typedef uint8_t uint32_le_t[4];
/**@brief Byte array type. */
typedef struct
{
uint16_t size; /**< Number of array entries. */
uint8_t * p_data; /**< Pointer to array entries. */
} uint8_array_t;
/**@brief Perform rounded integer division (as opposed to truncating the result).
*
* @param[in] A Numerator.
* @param[in] B Denominator.
*
* @return Rounded (integer) result of dividing A by B.
*/
#define ROUNDED_DIV(A, B) (((A) + ((B) / 2)) / (B))
/**@brief Check if the integer provided is a power of two.
*
* @param[in] A Number to be tested.
*
* @return true if value is power of two.
* @return false if value not power of two.
*/
#define IS_POWER_OF_TWO(A) ( ((A) != 0) && ((((A) - 1) & (A)) == 0) )
/**@brief To convert milliseconds to ticks.
* @param[in] TIME Number of milliseconds to convert.
* @param[in] RESOLUTION Unit to be converted to in [us/ticks].
*/
#define MSEC_TO_UNITS(TIME, RESOLUTION) (((TIME) * 1000) / (RESOLUTION))
/**@brief Perform integer division, making sure the result is rounded up.
*
* @details One typical use for this is to compute the number of objects with size B is needed to
* hold A number of bytes.
*
* @param[in] A Numerator.
* @param[in] B Denominator.
*
* @return Integer result of dividing A by B, rounded up.
*/
#define CEIL_DIV(A, B) \
/*lint -save -e573 */ \
((((A) - 1) / (B)) + 1) \
/*lint -restore */
/**@brief Function for encoding a uint16 value.
*
* @param[in] value Value to be encoded.
* @param[out] p_encoded_data Buffer where the encoded data is to be written.
*
* @return Number of bytes written.
*/
static __INLINE uint8_t uint16_encode(uint16_t value, uint8_t * p_encoded_data)
{
p_encoded_data[0] = (uint8_t) ((value & 0x00FF) >> 0);
p_encoded_data[1] = (uint8_t) ((value & 0xFF00) >> 8);
return sizeof(uint16_t);
}
/**@brief Function for encoding a uint32 value.
*
* @param[in] value Value to be encoded.
* @param[out] p_encoded_data Buffer where the encoded data is to be written.
*
* @return Number of bytes written.
*/
static __INLINE uint8_t uint32_encode(uint32_t value, uint8_t * p_encoded_data)
{
p_encoded_data[0] = (uint8_t) ((value & 0x000000FF) >> 0);
p_encoded_data[1] = (uint8_t) ((value & 0x0000FF00) >> 8);
p_encoded_data[2] = (uint8_t) ((value & 0x00FF0000) >> 16);
p_encoded_data[3] = (uint8_t) ((value & 0xFF000000) >> 24);
return sizeof(uint32_t);
}
/**@brief Function for decoding a uint16 value.
*
* @param[in] p_encoded_data Buffer where the encoded data is stored.
*
* @return Decoded value.
*/
static __INLINE uint16_t uint16_decode(const uint8_t * p_encoded_data)
{
return ( (((uint16_t)((uint8_t *)p_encoded_data)[0])) |
(((uint16_t)((uint8_t *)p_encoded_data)[1]) << 8 ));
}
/**@brief Function for decoding a uint32 value.
*
* @param[in] p_encoded_data Buffer where the encoded data is stored.
*
* @return Decoded value.
*/
static __INLINE uint32_t uint32_decode(const uint8_t * p_encoded_data)
{
return ( (((uint32_t)((uint8_t *)p_encoded_data)[0]) << 0) |
(((uint32_t)((uint8_t *)p_encoded_data)[1]) << 8) |
(((uint32_t)((uint8_t *)p_encoded_data)[2]) << 16) |
(((uint32_t)((uint8_t *)p_encoded_data)[3]) << 24 ));
}
/** @brief Function for converting the input voltage (in milli volts) into percentage of 3.0 Volts.
*
* @details The calculation is based on a linearized version of the battery's discharge
* curve. 3.0V returns 100% battery level. The limit for power failure is 2.1V and
* is considered to be the lower boundary.
*
* The discharge curve for CR2032 is non-linear. In this model it is split into
* 4 linear sections:
* - Section 1: 3.0V - 2.9V = 100% - 42% (58% drop on 100 mV)
* - Section 2: 2.9V - 2.74V = 42% - 18% (24% drop on 160 mV)
* - Section 3: 2.74V - 2.44V = 18% - 6% (12% drop on 300 mV)
* - Section 4: 2.44V - 2.1V = 6% - 0% (6% drop on 340 mV)
*
* These numbers are by no means accurate. Temperature and
* load in the actual application is not accounted for!
*
* @param[in] mvolts The voltage in mV
*
* @return Battery level in percent.
*/
static __INLINE uint8_t battery_level_in_percent(const uint16_t mvolts)
{
uint8_t battery_level;
if (mvolts >= 3000)
{
battery_level = 100;
}
else if (mvolts > 2900)
{
battery_level = 100 - ((3000 - mvolts) * 58) / 100;
}
else if (mvolts > 2740)
{
battery_level = 42 - ((2900 - mvolts) * 24) / 160;
}
else if (mvolts > 2440)
{
battery_level = 18 - ((2740 - mvolts) * 12) / 300;
}
else if (mvolts > 2100)
{
battery_level = 6 - ((2440 - mvolts) * 6) / 340;
}
else
{
battery_level = 0;
}
return battery_level;
}
/**@brief Function for checking if a pointer value is aligned to a 4 byte boundary.
*
* @param[in] p Pointer value to be checked.
*
* @return TRUE if pointer is aligned to a 4 byte boundary, FALSE otherwise.
*/
static __INLINE bool is_word_aligned(void * p)
{
return (((uintptr_t)p & 0x03) == 0);
}
#endif // APP_UTIL_H__
/** @} */
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