utils.c

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#include <esp8266.h>
//#include "mqtt.h"
#include "config.h"
#include "user_config.h"
#include "debug.h"
#include "utils.h"
#include "tinyprintf.h"

// crc table
const uint16_t ccit_crc16_table[256] = {
    0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
    0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
    0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
    0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
    0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
    0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
    0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
    0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
    0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
    0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
    0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
    0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
    0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
    0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
    0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
    0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
    0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
    0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
    0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
    0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
    0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
    0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
    0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
    0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
    0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
    0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
    0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
    0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
    0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
    0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
    0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
    0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
};

// CRC-CCITT (XModem)
ICACHE_FLASH_ATTR
uint16_t ccit_crc16(uint16_t crc16, uint8_t *data_p, unsigned int length) {
    while (length--) {
        crc16 = (crc16 << 8) ^ ccit_crc16_table[((crc16 >> 8) ^ *data_p++) & 0x00FF];
    }
    return crc16;
}

ICACHE_FLASH_ATTR void w_to_kw_str(char *w, char *kw) {
    uint32_t result_int, result_frac;
    uint32_t w_int;
    
    w_int = atoi(w);
    
    // ...divide by 1000 and prepare decimal string in kWh
    result_int = (int32_t)(w_int / 1000);
    result_frac = w_int % 1000;
    
    tfp_snprintf(kw, 15, "%u.%03u", result_int, result_frac);
}

ICACHE_FLASH_ATTR void kw_to_w_str(char *kw, char *w) {
    uint32_t result_int, result_frac;
    uint32_t i;
    uint32_t len;
    
    bool dec_separator;
    
    char result_int_str[32 + 1];
    
    uint32_t pos_int;
    uint32_t pos_frac;
    
    len = strlen(kw);
    
    result_frac = 0;
    pos_int = 0;
    pos_frac = 0;
    dec_separator = false;
    for (i = 0; i < len && pos_frac < 3; i++) {
        if (kw[i] == '.') {
            dec_separator = 1;
        }
        else if (!dec_separator) {
            result_int_str[pos_int++] = kw[i];
        }
        else {
            //result_frac_str[pos_frac++] = kw[i];
            result_frac += (kw[i] - '0') * int_pow(10, 2 - pos_frac);
            pos_frac++;
        }
    }
    result_int_str[pos_int] = 0;    // null terminate
    result_int = 1000 * atoi(result_int_str);   // multiply by 1000
    
    result_int += result_frac;
    tfp_snprintf(w, 11, "%u", result_int);
}

ICACHE_FLASH_ATTR void mw_to_w_str(char *mw, char *w) {
    // just a wrapper
    kw_to_w_str(mw, w);
}

ICACHE_FLASH_ATTR void divide_str_by_10(char *str, char *decimal_str) {
    int32_t result_int, result_frac;
    int32_t value_int;
    
    value_int = atoi(str);
    
    // ...divide by 10 and prepare decimal string
    result_int = (int32_t)(value_int / 10);
    if (result_int < 0) {
        result_frac = -1 * (value_int % 10);
    }
    else {
        result_frac = value_int % 100;
    }
    
    tfp_snprintf(decimal_str, 8, "%d.%01u", result_int, result_frac);
}

ICACHE_FLASH_ATTR void divide_str_by_100(char *str, char *decimal_str) {
    int32_t result_int, result_frac;
    int32_t value_int;
    
    value_int = atoi(str);
    
    // ...divide by 100 and prepare decimal string
    result_int = (int32_t)(value_int / 100);
    if (result_int < 0) {
        result_frac = -1 * (value_int % 100);
    }
    else {
        result_frac = value_int % 100;
    }
    
    tfp_snprintf(decimal_str, 8, "%d.%02u", result_int, result_frac);
}

ICACHE_FLASH_ATTR void divide_str_by_1000(char *str, char *decimal_str) {
    // just a wrapper
    w_to_kw_str(str, decimal_str);
}

ICACHE_FLASH_ATTR void cleanup_decimal_str(char *decimal_str, char *cleaned_up_str, unsigned int length) {
    uint32_t value_int, value_frac;
    char *pos;
    uint8_t decimals = 0;
    uint8_t prepend_zeroes;
    char zeroes[8];
    
    memcpy(cleaned_up_str, decimal_str, length);
    cleaned_up_str[length] = 0; // null terminate
    
    pos = strstr(cleaned_up_str, ".");
    if (pos == NULL) {
        // non fractional number
        value_int = atoi(cleaned_up_str);
        tfp_snprintf(cleaned_up_str, length, "%u", value_int);
    }
    else {
        // parse frac
        while ((*(pos + 1 + decimals) >= '0') && (*(pos + 1 + decimals) <= '9')) {
            // count the decimals
            decimals++;
        }
        value_frac = atoi(pos + 1);
        prepend_zeroes = decimals - decimal_number_length(atoi(pos + 1));
        
        zeroes[0] = 0;  // null terminate
        while (prepend_zeroes--) {
            strcat(zeroes, "0");
        }
        
        // parse int
        strncpy(cleaned_up_str, decimal_str, (pos - cleaned_up_str));
        cleaned_up_str[cleaned_up_str - pos] = 0;   // null terminate
        value_int = atoi(cleaned_up_str);
        
        tfp_snprintf(cleaned_up_str, length, "%u.%s%u", value_int, zeroes, value_frac);
    }
}

ICACHE_FLASH_ATTR
unsigned int decimal_number_length(int n) {
    int digits;
    
    digits = n < 0; //count "minus"
    do {
        digits++;
    } while (n /= 10);
    
    return digits;
}

ICACHE_FLASH_ATTR
int int_pow(int x, int y) {
    int i;
    int result;
    
    if (y == 0) {
        return 1;
    }
    
    result = x;
    for (i = 1; i < y; i++) {
        result *= x;
    }
    return result;
}