* CommonCLI: "get " commands

src/helpers/TxtDataHelpers.cpp

@@ -18,3 +18,117 @@ void StrHelper::strzcpy(char* dest, const char* src, size_t buf_sz) {
     buf_sz--;
   }
 }
+
+#include <Arduino.h>
+
+union int32_Float_t 
+{
+  int32_t Long;
+  float Float;
+};
+
+#ifndef FLT_MIN_EXP
+#define FLT_MIN_EXP (-999)
+#endif
+ 
+#ifndef FLT_MAX_EXP
+#define FLT_MAX_EXP (999)
+#endif
+ 
+#define _FTOA_TOO_LARGE -2  // |input| > 2147483520 
+#define _FTOA_TOO_SMALL -1  // |input| < 0.0000001 
+ 
+//precision 0-9
+#define PRECISION 7
+ 
+//_ftoa function 
+static void _ftoa(float f, char *p, int *status) 
+{
+  int32_t mantissa, int_part, frac_part;
+  int16_t exp2;
+  int32_Float_t x;
+ 
+  *status = 0;
+  if (f == 0.0) 
+  {
+    *p++ = '0';
+    *p++ = '.';
+    *p++ = '0';
+    *p = 0;
+    return;
+  }
+ 
+  x.Float = f;
+  exp2 = (unsigned char)(x.Long>>23) - 127;
+  mantissa = (x.Long&0xFFFFFF) | 0x800000;
+  frac_part = 0;
+  int_part = 0;
+ 
+  if (exp2 >= 31) 
+  {
+    *status = _FTOA_TOO_LARGE;
+    return;
+  } 
+  else if (exp2 < -23) 
+  {
+    *status = _FTOA_TOO_SMALL;
+    return;
+  } 
+  else if (exp2 >= 23)
+  { 
+    int_part = mantissa<<(exp2 - 23);
+  }
+  else if (exp2 >= 0) 
+  {
+    int_part = mantissa>>(23 - exp2);
+    frac_part = (mantissa<<(exp2 + 1))&0xFFFFFF;
+  } 
+  else 
+  {
+    //if (exp2 < 0)
+    frac_part = (mantissa&0xFFFFFF)>>-(exp2 + 1);
+  }
+ 
+  if (x.Long < 0)
+      *p++ = '-';
+  if (int_part == 0)
+    *p++ = '0';
+  else 
+  {
+    ltoa(int_part, p, 10);
+    while (*p)
+      p++;
+  }
+  *p++ = '.';
+  if (frac_part == 0)
+    *p++ = '0';
+  else 
+  {
+    char m;
+ 
+    for (m=0; m<PRECISION; m++) 
+    {
+      //frac_part *= 10;
+      frac_part = (frac_part<<3) + (frac_part<<1); 
+      *p++ = (frac_part>>24) + '0';
+      frac_part &= 0xFFFFFF;
+    }
+ 
+    //delete ending zeroes
+    for (--p; p[0] == '0' && p[-1] != '.'; --p)
+      ;
+    ++p;
+  }
+  *p = 0;
+}
+
+const char* StrHelper::ftoa(float f) {
+  static char tmp[16];
+  int status;
+  _ftoa(f, tmp, &status);
+  if (status) {
+    tmp[0] = '0';  // fallback/error value
+    tmp[1] = 0;
+  }
+  return tmp;
+}