Renato Grottesi / mbed-dev-bin

Microbit as a BLE gamepad

Dependents:   microbit-dal

Fork of mbed-dev-bin by Lancaster University

TARGET_NRF51_MICROBIT/TARGET_NORDIC/TARGET_MCU_NRF51822/Lib/nordic_sdk/components/libraries/util/app_util.h@4:bb4b3734941b, 2017-01-30 (annotated)

Committer:
rengro01
Date:
Mon Jan 30 08:23:23 2017 +0000
Revision:
4:bb4b3734941b
Parent:
0:e1a608bb55e8 
Microbit as a BLE gamepad

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jamesadevine 0:e1a608bb55e8 1 /* Copyright (c) 2012 Nordic Semiconductor. All Rights Reserved.
jamesadevine 0:e1a608bb55e8 2 *
jamesadevine 0:e1a608bb55e8 3 * The information contained herein is property of Nordic Semiconductor ASA.
jamesadevine 0:e1a608bb55e8 4 * Terms and conditions of usage are described in detail in NORDIC
jamesadevine 0:e1a608bb55e8 5 * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT.
jamesadevine 0:e1a608bb55e8 6 *
jamesadevine 0:e1a608bb55e8 7 * Licensees are granted free, non-transferable use of the information. NO
jamesadevine 0:e1a608bb55e8 8 * WARRANTY of ANY KIND is provided. This heading must NOT be removed from
jamesadevine 0:e1a608bb55e8 9 * the file.
jamesadevine 0:e1a608bb55e8 10 *
jamesadevine 0:e1a608bb55e8 11 */
jamesadevine 0:e1a608bb55e8 12
jamesadevine 0:e1a608bb55e8 13 /** @file
jamesadevine 0:e1a608bb55e8 14 *
jamesadevine 0:e1a608bb55e8 15 * @defgroup app_util Utility Functions and Definitions
jamesadevine 0:e1a608bb55e8 16 * @{
jamesadevine 0:e1a608bb55e8 17 * @ingroup app_common
jamesadevine 0:e1a608bb55e8 18 *
jamesadevine 0:e1a608bb55e8 19 * @brief Various types and definitions available to all applications.
jamesadevine 0:e1a608bb55e8 20 */
jamesadevine 0:e1a608bb55e8 21
jamesadevine 0:e1a608bb55e8 22 #ifndef APP_UTIL_H__
jamesadevine 0:e1a608bb55e8 23 #define APP_UTIL_H__
jamesadevine 0:e1a608bb55e8 24
jamesadevine 0:e1a608bb55e8 25 #include <stdint.h>
jamesadevine 0:e1a608bb55e8 26 #include <stdbool.h>
jamesadevine 0:e1a608bb55e8 27 #include "compiler_abstraction.h"
jamesadevine 0:e1a608bb55e8 28
jamesadevine 0:e1a608bb55e8 29 enum
jamesadevine 0:e1a608bb55e8 30 {
jamesadevine 0:e1a608bb55e8 31 UNIT_0_625_MS = 625, /**< Number of microseconds in 0.625 milliseconds. */
jamesadevine 0:e1a608bb55e8 32 UNIT_1_25_MS = 1250, /**< Number of microseconds in 1.25 milliseconds. */
jamesadevine 0:e1a608bb55e8 33 UNIT_10_MS = 10000 /**< Number of microseconds in 10 milliseconds. */
jamesadevine 0:e1a608bb55e8 34 };
jamesadevine 0:e1a608bb55e8 35
jamesadevine 0:e1a608bb55e8 36 /**@brief Macro for doing static (i.e. compile time) assertion.
jamesadevine 0:e1a608bb55e8 37 *
jamesadevine 0:e1a608bb55e8 38 * @note If the assertion fails when compiling using Keil, the compiler will report error message
jamesadevine 0:e1a608bb55e8 39 * "error: #94: the size of an array must be greater than zero" (while gcc will list the
jamesadevine 0:e1a608bb55e8 40 * symbol static_assert_failed, making the error message more readable).
jamesadevine 0:e1a608bb55e8 41 * If the supplied expression can not be evaluated at compile time, Keil will report
jamesadevine 0:e1a608bb55e8 42 * "error: #28: expression must have a constant value".
jamesadevine 0:e1a608bb55e8 43 *
jamesadevine 0:e1a608bb55e8 44 * @note The macro is intentionally implemented not using do while(0), allowing it to be used
jamesadevine 0:e1a608bb55e8 45 * outside function blocks (e.g. close to global type- and variable declarations).
jamesadevine 0:e1a608bb55e8 46 * If used in a code block, it must be used before any executable code in this block.
jamesadevine 0:e1a608bb55e8 47 *
jamesadevine 0:e1a608bb55e8 48 * @param[in] EXPR Constant expression to be verified.
jamesadevine 0:e1a608bb55e8 49 */
jamesadevine 0:e1a608bb55e8 50
jamesadevine 0:e1a608bb55e8 51 #if defined(__GNUC__)
jamesadevine 0:e1a608bb55e8 52 #define STATIC_ASSERT(EXPR) typedef char __attribute__((unused)) static_assert_failed[(EXPR) ? 1 : -1]
jamesadevine 0:e1a608bb55e8 53 #elif defined(__ICCARM__)
jamesadevine 0:e1a608bb55e8 54 #define STATIC_ASSERT(EXPR) extern char static_assert_failed[(EXPR) ? 1 : -1]
jamesadevine 0:e1a608bb55e8 55 #else
jamesadevine 0:e1a608bb55e8 56 #define STATIC_ASSERT(EXPR) typedef char static_assert_failed[(EXPR) ? 1 : -1]
jamesadevine 0:e1a608bb55e8 57 #endif
jamesadevine 0:e1a608bb55e8 58
jamesadevine 0:e1a608bb55e8 59
jamesadevine 0:e1a608bb55e8 60 /**@brief type for holding an encoded (i.e. little endian) 16 bit unsigned integer. */
jamesadevine 0:e1a608bb55e8 61 typedef uint8_t uint16_le_t[2];
jamesadevine 0:e1a608bb55e8 62
jamesadevine 0:e1a608bb55e8 63 /**@brief type for holding an encoded (i.e. little endian) 32 bit unsigned integer. */
jamesadevine 0:e1a608bb55e8 64 typedef uint8_t uint32_le_t[4];
jamesadevine 0:e1a608bb55e8 65
jamesadevine 0:e1a608bb55e8 66 /**@brief Byte array type. */
jamesadevine 0:e1a608bb55e8 67 typedef struct
jamesadevine 0:e1a608bb55e8 68 {
jamesadevine 0:e1a608bb55e8 69 uint16_t size; /**< Number of array entries. */
jamesadevine 0:e1a608bb55e8 70 uint8_t * p_data; /**< Pointer to array entries. */
jamesadevine 0:e1a608bb55e8 71 } uint8_array_t;
jamesadevine 0:e1a608bb55e8 72
jamesadevine 0:e1a608bb55e8 73 /**@brief Perform rounded integer division (as opposed to truncating the result).
jamesadevine 0:e1a608bb55e8 74 *
jamesadevine 0:e1a608bb55e8 75 * @param[in] A Numerator.
jamesadevine 0:e1a608bb55e8 76 * @param[in] B Denominator.
jamesadevine 0:e1a608bb55e8 77 *
jamesadevine 0:e1a608bb55e8 78 * @return Rounded (integer) result of dividing A by B.
jamesadevine 0:e1a608bb55e8 79 */
jamesadevine 0:e1a608bb55e8 80 #define ROUNDED_DIV(A, B) (((A) + ((B) / 2)) / (B))
jamesadevine 0:e1a608bb55e8 81
jamesadevine 0:e1a608bb55e8 82 /**@brief Check if the integer provided is a power of two.
jamesadevine 0:e1a608bb55e8 83 *
jamesadevine 0:e1a608bb55e8 84 * @param[in] A Number to be tested.
jamesadevine 0:e1a608bb55e8 85 *
jamesadevine 0:e1a608bb55e8 86 * @return true if value is power of two.
jamesadevine 0:e1a608bb55e8 87 * @return false if value not power of two.
jamesadevine 0:e1a608bb55e8 88 */
jamesadevine 0:e1a608bb55e8 89 #define IS_POWER_OF_TWO(A) ( ((A) != 0) && ((((A) - 1) & (A)) == 0) )
jamesadevine 0:e1a608bb55e8 90
jamesadevine 0:e1a608bb55e8 91 /**@brief To convert milliseconds to ticks.
jamesadevine 0:e1a608bb55e8 92 * @param[in] TIME Number of milliseconds to convert.
jamesadevine 0:e1a608bb55e8 93 * @param[in] RESOLUTION Unit to be converted to in [us/ticks].
jamesadevine 0:e1a608bb55e8 94 */
jamesadevine 0:e1a608bb55e8 95 #define MSEC_TO_UNITS(TIME, RESOLUTION) (((TIME) * 1000) / (RESOLUTION))
jamesadevine 0:e1a608bb55e8 96
jamesadevine 0:e1a608bb55e8 97
jamesadevine 0:e1a608bb55e8 98 /**@brief Perform integer division, making sure the result is rounded up.
jamesadevine 0:e1a608bb55e8 99 *
jamesadevine 0:e1a608bb55e8 100 * @details One typical use for this is to compute the number of objects with size B is needed to
jamesadevine 0:e1a608bb55e8 101 * hold A number of bytes.
jamesadevine 0:e1a608bb55e8 102 *
jamesadevine 0:e1a608bb55e8 103 * @param[in] A Numerator.
jamesadevine 0:e1a608bb55e8 104 * @param[in] B Denominator.
jamesadevine 0:e1a608bb55e8 105 *
jamesadevine 0:e1a608bb55e8 106 * @return Integer result of dividing A by B, rounded up.
jamesadevine 0:e1a608bb55e8 107 */
jamesadevine 0:e1a608bb55e8 108 #define CEIL_DIV(A, B) \
jamesadevine 0:e1a608bb55e8 109 /*lint -save -e573 */ \
jamesadevine 0:e1a608bb55e8 110 ((((A) - 1) / (B)) + 1) \
jamesadevine 0:e1a608bb55e8 111 /*lint -restore */
jamesadevine 0:e1a608bb55e8 112
jamesadevine 0:e1a608bb55e8 113 /**@brief Function for encoding a uint16 value.
jamesadevine 0:e1a608bb55e8 114 *
jamesadevine 0:e1a608bb55e8 115 * @param[in] value Value to be encoded.
jamesadevine 0:e1a608bb55e8 116 * @param[out] p_encoded_data Buffer where the encoded data is to be written.
jamesadevine 0:e1a608bb55e8 117 *
jamesadevine 0:e1a608bb55e8 118 * @return Number of bytes written.
jamesadevine 0:e1a608bb55e8 119 */
jamesadevine 0:e1a608bb55e8 120 static __INLINE uint8_t uint16_encode(uint16_t value, uint8_t * p_encoded_data)
jamesadevine 0:e1a608bb55e8 121 {
jamesadevine 0:e1a608bb55e8 122 p_encoded_data[0] = (uint8_t) ((value & 0x00FF) >> 0);
jamesadevine 0:e1a608bb55e8 123 p_encoded_data[1] = (uint8_t) ((value & 0xFF00) >> 8);
jamesadevine 0:e1a608bb55e8 124 return sizeof(uint16_t);
jamesadevine 0:e1a608bb55e8 125 }
jamesadevine 0:e1a608bb55e8 126
jamesadevine 0:e1a608bb55e8 127 /**@brief Function for encoding a uint32 value.
jamesadevine 0:e1a608bb55e8 128 *
jamesadevine 0:e1a608bb55e8 129 * @param[in] value Value to be encoded.
jamesadevine 0:e1a608bb55e8 130 * @param[out] p_encoded_data Buffer where the encoded data is to be written.
jamesadevine 0:e1a608bb55e8 131 *
jamesadevine 0:e1a608bb55e8 132 * @return Number of bytes written.
jamesadevine 0:e1a608bb55e8 133 */
jamesadevine 0:e1a608bb55e8 134 static __INLINE uint8_t uint32_encode(uint32_t value, uint8_t * p_encoded_data)
jamesadevine 0:e1a608bb55e8 135 {
jamesadevine 0:e1a608bb55e8 136 p_encoded_data[0] = (uint8_t) ((value & 0x000000FF) >> 0);
jamesadevine 0:e1a608bb55e8 137 p_encoded_data[1] = (uint8_t) ((value & 0x0000FF00) >> 8);
jamesadevine 0:e1a608bb55e8 138 p_encoded_data[2] = (uint8_t) ((value & 0x00FF0000) >> 16);
jamesadevine 0:e1a608bb55e8 139 p_encoded_data[3] = (uint8_t) ((value & 0xFF000000) >> 24);
jamesadevine 0:e1a608bb55e8 140 return sizeof(uint32_t);
jamesadevine 0:e1a608bb55e8 141 }
jamesadevine 0:e1a608bb55e8 142
jamesadevine 0:e1a608bb55e8 143 /**@brief Function for decoding a uint16 value.
jamesadevine 0:e1a608bb55e8 144 *
jamesadevine 0:e1a608bb55e8 145 * @param[in] p_encoded_data Buffer where the encoded data is stored.
jamesadevine 0:e1a608bb55e8 146 *
jamesadevine 0:e1a608bb55e8 147 * @return Decoded value.
jamesadevine 0:e1a608bb55e8 148 */
jamesadevine 0:e1a608bb55e8 149 static __INLINE uint16_t uint16_decode(const uint8_t * p_encoded_data)
jamesadevine 0:e1a608bb55e8 150 {
jamesadevine 0:e1a608bb55e8 151 return ( (((uint16_t)((uint8_t *)p_encoded_data)[0])) |
jamesadevine 0:e1a608bb55e8 152 (((uint16_t)((uint8_t *)p_encoded_data)[1]) << 8 ));
jamesadevine 0:e1a608bb55e8 153 }
jamesadevine 0:e1a608bb55e8 154
jamesadevine 0:e1a608bb55e8 155 /**@brief Function for decoding a uint32 value.
jamesadevine 0:e1a608bb55e8 156 *
jamesadevine 0:e1a608bb55e8 157 * @param[in] p_encoded_data Buffer where the encoded data is stored.
jamesadevine 0:e1a608bb55e8 158 *
jamesadevine 0:e1a608bb55e8 159 * @return Decoded value.
jamesadevine 0:e1a608bb55e8 160 */
jamesadevine 0:e1a608bb55e8 161 static __INLINE uint32_t uint32_decode(const uint8_t * p_encoded_data)
jamesadevine 0:e1a608bb55e8 162 {
jamesadevine 0:e1a608bb55e8 163 return ( (((uint32_t)((uint8_t *)p_encoded_data)[0]) << 0) |
jamesadevine 0:e1a608bb55e8 164 (((uint32_t)((uint8_t *)p_encoded_data)[1]) << 8) |
jamesadevine 0:e1a608bb55e8 165 (((uint32_t)((uint8_t *)p_encoded_data)[2]) << 16) |
jamesadevine 0:e1a608bb55e8 166 (((uint32_t)((uint8_t *)p_encoded_data)[3]) << 24 ));
jamesadevine 0:e1a608bb55e8 167 }
jamesadevine 0:e1a608bb55e8 168
jamesadevine 0:e1a608bb55e8 169 /** @brief Function for converting the input voltage (in milli volts) into percentage of 3.0 Volts.
jamesadevine 0:e1a608bb55e8 170 *
jamesadevine 0:e1a608bb55e8 171 * @details The calculation is based on a linearized version of the battery's discharge
jamesadevine 0:e1a608bb55e8 172 * curve. 3.0V returns 100% battery level. The limit for power failure is 2.1V and
jamesadevine 0:e1a608bb55e8 173 * is considered to be the lower boundary.
jamesadevine 0:e1a608bb55e8 174 *
jamesadevine 0:e1a608bb55e8 175 * The discharge curve for CR2032 is non-linear. In this model it is split into
jamesadevine 0:e1a608bb55e8 176 * 4 linear sections:
jamesadevine 0:e1a608bb55e8 177 * - Section 1: 3.0V - 2.9V = 100% - 42% (58% drop on 100 mV)
jamesadevine 0:e1a608bb55e8 178 * - Section 2: 2.9V - 2.74V = 42% - 18% (24% drop on 160 mV)
jamesadevine 0:e1a608bb55e8 179 * - Section 3: 2.74V - 2.44V = 18% - 6% (12% drop on 300 mV)
jamesadevine 0:e1a608bb55e8 180 * - Section 4: 2.44V - 2.1V = 6% - 0% (6% drop on 340 mV)
jamesadevine 0:e1a608bb55e8 181 *
jamesadevine 0:e1a608bb55e8 182 * These numbers are by no means accurate. Temperature and
jamesadevine 0:e1a608bb55e8 183 * load in the actual application is not accounted for!
jamesadevine 0:e1a608bb55e8 184 *
jamesadevine 0:e1a608bb55e8 185 * @param[in] mvolts The voltage in mV
jamesadevine 0:e1a608bb55e8 186 *
jamesadevine 0:e1a608bb55e8 187 * @return Battery level in percent.
jamesadevine 0:e1a608bb55e8 188 */
jamesadevine 0:e1a608bb55e8 189 static __INLINE uint8_t battery_level_in_percent(const uint16_t mvolts)
jamesadevine 0:e1a608bb55e8 190 {
jamesadevine 0:e1a608bb55e8 191 uint8_t battery_level;
jamesadevine 0:e1a608bb55e8 192
jamesadevine 0:e1a608bb55e8 193 if (mvolts >= 3000)
jamesadevine 0:e1a608bb55e8 194 {
jamesadevine 0:e1a608bb55e8 195 battery_level = 100;
jamesadevine 0:e1a608bb55e8 196 }
jamesadevine 0:e1a608bb55e8 197 else if (mvolts > 2900)
jamesadevine 0:e1a608bb55e8 198 {
jamesadevine 0:e1a608bb55e8 199 battery_level = 100 - ((3000 - mvolts) * 58) / 100;
jamesadevine 0:e1a608bb55e8 200 }
jamesadevine 0:e1a608bb55e8 201 else if (mvolts > 2740)
jamesadevine 0:e1a608bb55e8 202 {
jamesadevine 0:e1a608bb55e8 203 battery_level = 42 - ((2900 - mvolts) * 24) / 160;
jamesadevine 0:e1a608bb55e8 204 }
jamesadevine 0:e1a608bb55e8 205 else if (mvolts > 2440)
jamesadevine 0:e1a608bb55e8 206 {
jamesadevine 0:e1a608bb55e8 207 battery_level = 18 - ((2740 - mvolts) * 12) / 300;
jamesadevine 0:e1a608bb55e8 208 }
jamesadevine 0:e1a608bb55e8 209 else if (mvolts > 2100)
jamesadevine 0:e1a608bb55e8 210 {
jamesadevine 0:e1a608bb55e8 211 battery_level = 6 - ((2440 - mvolts) * 6) / 340;
jamesadevine 0:e1a608bb55e8 212 }
jamesadevine 0:e1a608bb55e8 213 else
jamesadevine 0:e1a608bb55e8 214 {
jamesadevine 0:e1a608bb55e8 215 battery_level = 0;
jamesadevine 0:e1a608bb55e8 216 }
jamesadevine 0:e1a608bb55e8 217
jamesadevine 0:e1a608bb55e8 218 return battery_level;
jamesadevine 0:e1a608bb55e8 219 }
jamesadevine 0:e1a608bb55e8 220
jamesadevine 0:e1a608bb55e8 221 /**@brief Function for checking if a pointer value is aligned to a 4 byte boundary.
jamesadevine 0:e1a608bb55e8 222 *
jamesadevine 0:e1a608bb55e8 223 * @param[in] p Pointer value to be checked.
jamesadevine 0:e1a608bb55e8 224 *
jamesadevine 0:e1a608bb55e8 225 * @return TRUE if pointer is aligned to a 4 byte boundary, FALSE otherwise.
jamesadevine 0:e1a608bb55e8 226 */
jamesadevine 0:e1a608bb55e8 227 static __INLINE bool is_word_aligned(void * p)
jamesadevine 0:e1a608bb55e8 228 {
jamesadevine 0:e1a608bb55e8 229 return (((uintptr_t)p & 0x03) == 0);
jamesadevine 0:e1a608bb55e8 230 }
jamesadevine 0:e1a608bb55e8 231
jamesadevine 0:e1a608bb55e8 232 #endif // APP_UTIL_H__
jamesadevine 0:e1a608bb55e8 233
jamesadevine 0:e1a608bb55e8 234 /** @} */