The time transmitted from ALLSTAR DATA SOURCE is doubletype,and wanted to display time to LCD,so I want to convert double type to float ,and want to uS.How can i do that? Thanks a lot!
"How can i do that?" Can you provide a link to a document that describes the data output from this device, or provide a better description of it yourself? What exactly do you mean when you say 'double' - a 64 bit IEEE binary floating point value, an ASCII representation of a floating point value, or what?
Sorry ,I couldn't described the question clearly at noon.My mean is pointing to 64bits IEEE binary floating point value ,which binary structure as following: Double Float (64 bits ) MSB (bit 63) = Sign Bit 62..52 = Exp Bit 51..00 = Mantissa 2exp(-1*bit51) + 2 exp(-2*bit50)....... Value = Sign * 1.mantissa * 2 exp(EXP-1023) Thanks for your help!
"My mean is pointing to 64bits IEEE binary floating point value" In that case you will have to write your own routine to convert it to a 32 bit IEEE754 float. There is a good description of the 32 bit format on this website - search for IEEE.