Re: [DUG] RE: [DUG-Offtopic] Byte to Real conversion

[Phil Middlemiss]

Here is a very simple conversion from a dynamic byte array to a Single:   function BytesToSingle(Data: TByteDynArray;   Position: Integer): Single; {-------------------------------------------------------------------------  DESCRIPTION:  Accepts a byte array and returns a Single.  PARAMETERS:   The byte array and an integer specifying the position in the array to start.  RETURNS:      Single -------------------------------------------------------------------------} const   DATA_SIZE: Longint = 4; begin   if Position <= High(Data) - (DATA_SIZE - 1) then     Move(Data[Position], result, DATA_SIZE); end;   And a routine to convert from a Single to Bytes:   function SingleToBytes(Data: Single): TByteDynArray; {---------------------------------------------------------------------------    DESCRIPTION:    Converts the Single to a 4byte array.    PARAMETERS:     Data           The Single to convert    RETURNS:        TByteDynArray  The byte values separated into a byte array ---------------------------------------------------------------------------} const   DATA_SIZE : LongInt = 4; begin   SetLength(result, DATA_SIZE);   Move(Data, result[0], DATA_SIZE); end; The above routine could also easily be adapted to work with an existing byte array and take a pPosition parameter like the first routine.   ----- Original Message ----- From: Colin/Mina To: [EMAIL PROTECTED] Sent: Tuesday, August 31, 2004 9:29 PM Subject: [DUG] RE: [DUG-Offtopic] Byte to Real conversion Hi,   Any ideas please?   I am developing an embedded processor controller that needs to continuously communicate data over a link to another. The baud rate is limited to 9600 Bd. The numeric range of each data packet will need to be at least +/ 12 digits. I am concerned that the time taken to send this data may too high if sent as strings of characters and I would like to limit this.   My data values could be easily represented within the four bytes of a 'Single' which is the smallest Real type and would give me a range of 1.5 x 10 ^-45 .. 3.4 x 10 ^38. This being the case I could send the data as 4 x char(bytes) + a checksum and terminator.   My question is - What is the simplest way of doing the conversion in each direction. I have to deal with two different microprocessors, but the maths libraries I have in the compilers are not too bad. I've had a play but seem to be getting into problems with type casting.  A Pascal demo would be a great help.   Regards     Colin     _______________________________________________ Delphi mailing list [EMAIL PROTECTED] http://ns3.123.co.nz/mailman/listinfo/delphi

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