> From: Tam?s Fekete <tomy11proconsul@gmail.com>
>=20
>  I am using a dspic33fj128mc802 with mplab xc16 compiler. I have to read
> data from an ADC at about 1ms intervals. The data that I get is a floatin=
g
> point number. I convert this number into a string using the function
> sprintf. Send out the string. At the PC side I receive and save the data
> with putty.exe. Then save the session in a .dat file. I can use this .dat
> file with matlab to plot the results.
>=20
> The problem is that sprintf really slows down the process. I should be
> taking samples at about 1ms intervals and because of the sprintf function
> this is between 5-7 mseconds. I checked this with an oscilloscope and
> without the sprintf function I can get down to even less than 1ms interva=
ls
> easily.
>=20
> If anybody could suggest a faster way to make a string out of a floating
> point number or another way to send and receive the data I would be very
> thankful.
>=20
> Cheers
> Tomi
>=20

The output from the ADC is probably in Fractional notation, the dsPIS33F do=
es not support floating point notation. If you wish to convert that with an=
y speed then it would be better to write your own code. You should read up =
on the particular fractional notation that is used, I'm 99% certain that it=
 is Q15 but the information will be in the datasheet. Alternatively you can=
 send binary data directly to MATLAB if you use MATLAB's serial port object=
 and then convert the data once received.
regards
James
 		 	   		 =20
--=20
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