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helper.h
// helper functions for embedded projects // to be used when either the math functions are missing from libc // or when space is at a premium and snprintf is overkill // // author: Petre Rodan <2b4eda@subdimension.ro> // available from: https://github.com/rodan/reference_libs_msp430fr5x // license: GNU GPLv3 #ifndef __HELPER_H__ #define __HELPER_H__ #define PI 3.14159265358f #define PI_FLOAT 3.14159265f #define PIBY2_FLOAT 1.5707963f #define PREC 5 #define CONV_BASE_2_BUF_SZ 19 #define CONV_BASE_8_BUF_SZ 12 #define CONV_BASE_10_BUF_SZ 12 // -2147483648 + ending 0 is 12 bytes long typedef enum { PAD_NONE, PAD_ZEROES, PAD_SPACES, } pad_type; #ifdef __cplusplus extern "C" { #endif // math functions /** @param @return */ float _atan2f(float y, float x); /** calculate sine of an input @param input value (float) @return sin(input) */ float _sin(const float x); /** calculate the cosine of an input @param input value (float) @return sin(input) (float) */ float _cos(const float x); /** calulate the square root of an input @param input value (float) @return sqrt(input) (float) */ float _sqrt(const float number); /** convert degrees to radians @param degree value to be converted (float) @return resulting radians (float) */ float radians(const float x); /** return the square of a float @param input value to be squared (float) @return input^2 (float) */ float sq(const float x); // string functions /** return a binary string for an uint16_t integer @param temporary buffer used to build up the string. buf[CONV_BASE_2_BUF_SZ] needs to be pre-allocated @param uint16_t value @return pointer to the string */ char *_utob(char *buf, const uint16_t val); /** return a hex string for an uint32_t integer @param temporary buffer used to build up the string. buf[CONV_BASE_8_BUF_SZ] needs to be pre-allocated @param uint32_t value @return pointer to the string */ char *_utoh(char *buf, const uint32_t val); /** return a decimal string for an uint32_t integer @param temporary buffer used to build up the string. buf[CONV_BASE_10_BUF_SZ] needs to be pre-allocated @param uint32_t value @return pointer to the string */ char *_utoa(char *buf, const uint32_t val); /** return a decimal string for an int32_t integer @param temporary buffer used to build up the string. buf[CONV_BASE_10_BUF_SZ] needs to be pre-allocated @param int32_t value @return pointer to the string */ char *_itoa(char *buf, const int32_t val); /** return a string with prefixed padding @param pointer to originally allocated buffer @param pointer within the originally allocated buffer where the conversion is stored @param type of padding @param target total length of resulting string @return pointer to the resulting string. *converted_buf is returned on parameter error */ char *prepend_padding(char *buf, char *converted_buf, const pad_type padding_type, const uint8_t target_len); /** convert a string to a 32bit unsigned integer @param pointer to string to be converted @param pointer to resulting uint32_t value [min .. max] @param how many chars to skip [0 .. len-1] @param length of string to parse @param minimal value for result @param maximum value for result @return EXIT_FAILURE if resulting value is outside the limits, EXIT_SUCCESS otherwise */ uint8_t str_to_uint32(char *str, uint32_t * out, const uint8_t seek, const uint8_t len, const uint32_t min, const uint32_t max); /** convert a string to a 16bit unsigned integer @param pointer to string to be converted @param pointer to resulting uint16_t value [min .. max] @param how many chars to skip [0 .. len-1] @param length of string to parse @param minimal value for result @param maximum value for result @return EXIT_FAILURE if resulting value is outside the limits, EXIT_SUCCESS otherwise */ uint8_t str_to_uint16(char *str, uint16_t * out, const uint8_t seek, const uint8_t len, const uint16_t min, const uint16_t max); /** convert a base-10 integer value to a binary-coded decimal (BCD) @param input decimal value to be converted @return BCD conversion */ uint8_t dec_to_bcd(const uint8_t val); /** convert a binary-coded decimal (BCD) to a base-10 integer value @param BCD integer to be converted @return input decimal value to be converted */ uint8_t bcd_to_dec(const uint8_t val); #ifdef __cplusplus } #endif #endif
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