Diff: float2str.h

Revision:

0:d8558b73ffd7

Child:

1:89abb5f1c2fd

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/float2str.h	Fri Sep 02 15:04:03 2016 +0000
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+/*
+    Copyright (c) 2016 Jens Strümper
+ 
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+ 
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+ 
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+*/
+
+#ifndef MBED_H
+#include "mbed.h"
+#endif
+
+#ifndef FLOAT2STR_H
+#define FLOAT2STR_H
+
+namespace js {
+
+/** float2str converts floating point numbers to a character array. Its purpose is to 
+ * have a character representation of floating point numbers when printf floating point support
+ * is not enabled by compiler options. 
+ *
+ * This is done by:  . 
+ *  <ul>
+ *  <li> Separating the integer from the fract part of the floating point number. </li>
+ *  <li> Casting both parts to integer </li> 
+ *  <li> Convert the integers to char arrays </li>
+ *  <li> Add the "." seperator and padding zeros behind the "." </li>
+ *  <li> return the compile charater array </li>
+ *  </ul>
+ * The toString function takes two arguments:
+ *  <ul>
+ *  <li> Floating point number that shall be converted </li>
+ *  <li> Number of digits after the "." </li> 
+ *  </ul>
+ *
+ * Only callbacks that have been attached will be called by the library.
+ *
+ * Example:
+ * @code
+ * #include "mbed.h"
+ * #include "float2str.h"
+ *
+ * float number = 13.467472;
+ * char *string;
+ *
+ * int main(){
+ *
+ * while(1){
+ *   float number = static_cast <float> (rand()) / (static_cast <float> (100000));
+ *   charArray = toString (number, 5);
+ *   printf ("Char Array: %s Float: %f \r\n", charArray, number );
+ *   wait(1);
+ * }    
+ * @endcode
+ *
+ * This example will convert randomly generated floating point numbers to a character array of fixed lenght [10]. 
+ *
+ */
+
+
+/*
+** reverse string in place 
+*/
+void reverse(char *s) {
+char *j;
+int c;
+ 
+    j = s + strlen(s) - 1;
+    while(s < j) {
+        c = *s;
+        *s++ = *j;
+        *j-- = c;
+    }
+}
+/*
+** itoa:  convert n to characters in s 
+*/
+void itoa(int n, char s[])
+{
+    int i, sign;
+    
+    if ((sign = n) < 0)                 /* record sign */
+        n = -n;                         /* make n positive */
+        i = 0;
+    do {                                /* generate digits in reverse order */
+         s[i++] = n % 10 + '0';         /* get next digit */
+        } while ((n /= 10) > 0);        /* delete it */
+    if (sign < 0)
+        s[i++] = '-';
+        s[i] = '\0';
+    reverse(s);
+}
+
+/*
+** toString:  convert floating point number to 
+*/
+
+char *toString(float number, int digits)
+{
+    int d1;
+    int d2;
+    char buf_d1[10];
+    char buf_d2[10];
+    static char buf_out[10];
+//    char padzero[10];
+    double fractpart, intpart;   
+    int multiplier=1;
+    
+    for (int j=0; j < digits; j++){
+        multiplier = multiplier * 10;
+        } 
+    fractpart = modf (number , &intpart);
+    d2 = int(fractpart*multiplier);
+    d1 = int(intpart);    
+    itoa(d1, buf_d1);
+    itoa(d2, buf_d2); 
+       
+    strcpy(buf_out, buf_d1);
+    strcat(buf_out, ".");
+    
+    if (strlen(buf_d2) < digits) {      /* adding n padding zero's if nessesary */
+        for (int k=0; k < (digits - strlen(buf_d2)); k++){
+            strcat(buf_out, "0");
+        }
+    }
+    strcat(buf_out, buf_d2);  
+
+    return buf_out;  
+}
+
+}; 
+
+using namespace js;
+
+#endif
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