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sama · 01-12-2007, 08:20 AM

ok, I was on my lunch break and it just hit me! It's a lot easier than I thought...

the number coming back is not an 8 bit, nor is it a 10 bit. It's 16bit! and we don't need to do anything to it. just need to read it as a 16 bit short integer!

so:

assume the sign byte is 254 and the value byte is 0. We know that 254 means the second-lung and negative. So this should be -255

now we create a short (initialised to 0)
0000 0000 0000 0000

assign the first number (the one that is 0, 1, 254 or 255 - 254 is used as an example):
0000 0000 1111 1110

shift it by 8 bits to the left
1111 1110 0000 0000

do a bitwise xorOR (EDIT:xor would be totally wrong!) with the value (assume 1)

Code:

1111 1110 0000 0000
OR
          0000 0001
--------------------
1111 1110 0000 0001 = -255 (assuming singed short)

Bob's your uncle!

01-12-2007, 08:20 AM	#28
sama FLAC sama's CarPC Specs Join Date: Feb 2006 Location: London, UK Vehicle: BMW 850CSi Posts: 1,280 My Photos: ()	ok, I was on my lunch break and it just hit me! It's a lot easier than I thought... the number coming back is not an 8 bit, nor is it a 10 bit. It's 16bit! and we don't need to do anything to it. just need to read it as a 16 bit short integer! so: assume the sign byte is 254 and the value byte is 0. We know that 254 means the second-lung and negative. So this should be -255 now we create a short (initialised to 0) 0000 0000 0000 0000 assign the first number (the one that is 0, 1, 254 or 255 - 254 is used as an example): 0000 0000 1111 1110 shift it by 8 bits to the left 1111 1110 0000 0000 do a bitwise xorOR (EDIT:xor would be totally wrong!) with the value (assume 1) Code: 1111 1110 0000 0000 OR 0000 0001 -------------------- 1111 1110 0000 0001 = -255 (assuming singed short) Bob's your uncle! __________________ ///Mputer - Velocity - TomTom - Vision - Bezel - CarPC Last edited by sama : 01-13-2007 at 07:31 AM.