Hello,
I am trying to use BLE to transfer orientation from a BNO055 sensor data to an app on a tablet. My orientation data from the sensor has double data type but for programming of the app it is much easier to receive the 4 components (w,x,y,z) as a string. At first I thought this would be easy using the dtostrf() function, however, now I am realizing that is only part avr library and will not work for my mkr wifi 1010. has anyone made or found a simple function to convert doubles to strings with this board?
Worded differently: I have 4 double variables and I want to convert them to a string with commas seperating each variable.
What I have
double w = 0.12
double x = -3.45
double y = 6.78
double z = -9.10
and I want to convert this to a string "0.12,-3.45,6.78,-9.10"
I have done some looking around the forum without much luck, if you know a simple solution or where i can find one it would be greatly appreciated.
Thanks,
Chris
If anyone else is interested in this after about 5 more hours of digging i found this thread which at the end gives the following dtostrf function which seems to work so far.
char * dtostrf(double number, signed char width, unsigned char prec, char *s) {
if (isnan(number)) {
strcpy(s, "nan");
return s;
}
if (isinf(number)) {
strcpy(s, "inf");
return s;
}
char* out = s;
int fillme = width; // how many cells to fill for the integer part
if (prec > 0) {
fillme -= (prec+1);
}
// Handle negative numbers
if (number < 0.0) {
*out++ = '-';
fillme--;
number = -number;
}
// Round correctly so that print(1.999, 2) prints as "2.00"
// I optimized out most of the divisions
double rounding = 2.0;
for (uint8_t i = 0; i < prec; ++i)
rounding *= 10.0;
rounding = 1.0 / rounding;
number += rounding;
// Figure out how big our number really is
double tenpow = 1.0;
int digitcount = 1;
while (number >= 10.0 * tenpow) {
tenpow *= 10.0;
digitcount++;
}
number /= tenpow;
fillme -= digitcount;
// Pad unused cells with spaces
while (fillme-- > 0) {
*out++ = ' ';
}
// Print the digits, and if necessary, the decimal point
digitcount += prec;
int8_t digit = 0;
while (digitcount-- > 0) {
digit = (int8_t)number;
if (digit > 9) digit = 9; // insurance
*out++ = (char)('0' | digit);
if ((digitcount == prec) && (prec > 0)) {
*out++ = '.';
}
number -= digit;
number *= 10.0;
}
// make sure the string is terminated
*out = 0;
return s;
}
dtostrf does not seem extremely popular, so I had my troubles and started to write my own, just in case someone else need it: