dtostrf in Energia

[spirilis 1,265]

Good work!  I usually like to allocate at least 16 bytes for any sprintf type of stuff like that.  (even on MSP430)

[jcR 6]

Hello all

 

Mikal Hart has developed two libraries for arduino that are easily portable to the platform Stellaris / Tiva.
They are called PString and Streaming, and are available on its website:

http://arduiniana.org/libraries/pstring/
PString solves  with a very smart way the   floating point conversion to  characters  string, following this example:

 

#include "PString.h"
#include "Streaming.h"

 

char buffer[10];

double pi=3.141592;

void setup()
{
  PString   str(buffer, sizeof(buffer));// create the string str in buffer
 
   Serial.begin(115200);  


  Serial << "PI in a string: ";
  // Print PI to a string with 6 decimals
  // sprintf(buffer, "%.6f", pi);
  // Print the string to the serial terminal
  //Serial.println(buffer);

 str.begin();// reset str
 str.println  (pi,6);// store pi to str with 6 decimals
 Serial << str  << endl; // print à la C++

}

The advantage is that the memory consumption is lower by more than 20 kbytes over the sprintf function and in addition there is no risk of having a memory overflow with dynamic strings

I use these two libraries in all my programs without any problem

Cordially.

[Rickta59 589]

[edit] ... heh .. never mind .. I had the wrong board selected [/edit]

The advantage is that the memory consumption is lower by more than 20 kbytes over the sprintf function and in addition there is no risk of having a memory overflow with dynamic strings

I've not seen a 20kbyte overhead associated with Energia's sprintf and floating point. Can you explain how you see that?

 

-rick

[jcR 6]

As exemple you can compile the simple WebServer.ino exemple for the CC3000 Wifi module (exemple in Energia IDE).

The binary sketch size is 42828 bytes .

If you remove the printHex(num,precision) wich use the sprintf routine, you have the Binary sketch wich down to 22656 bytes.

this is exactly what I describe in the above example.

Do you have read the exemples on the Mikal Hart web site for the PString usage.

I think this is the most elegant of solutions, with the advantage of not using sprintf.

Cordially

JC

Compiled with Energia 0101E0011 on W7 OS.