Reading Array values into variables

[mister_e]

>>4 => shift byte 4 position to the right. so you keep only the 4 high bits
& $F => Bitwise and with hex F. so you keep only the 4 low bits

everything is in the PBP manual section 4.17

[Bruce]

It's no more difficult than copying data from a single variable to another.

X VAR BYTE
Y VAR BYTE

X = 3
Y = X

You can state X = SSMAX(23), Y = SSMAX(34), etc,,.

Since the resulting value will be a word, then use something like this;

SSMAX(23) contains 83h
SSMAX(34) contains 03h

Result VAR WORD

Result.LowByte = SSMAX(23) ' Place 83h into lowbyte
Result.HighByte = SSMAX(34) ' Place 03h into highbyte
HSEROUT [DEC Result] ' Print decimal value of 0383h = 899

[Tom Gonser]

Seems like I should be able to figure this out, but I can't ...

I have an array that contains 24 bits which equate to an altitude in tenths of meters.

alt[1]
alt[2]
alt[3]


I need to 1) display this, and 2) convert from meters to feet, so I need to stuff all these into a single variable which represents actual meters as opposed to tenths of meters, then convert to feet....

Any ideas out there? They way I am doing it now is not working. I am just reading these into alt1, alt2, alt2, and showing them as #alt1, #alt2, #alt3... I get 13130 which may be 131.30 meters,(which would be about right) but I am not sure. I am also not sure how to make this a single variable ..

Thanks !

Tom

[Demon]

I have no answer, but I do see an immediate problem.

A byte contains 8 bits, a word contains 2 bytes; that's a total of 16 bits.

There is a way to do 32 bit math, I saw a section in the manual. You work with 2 separate words or something, I didn't pay much attention.

Robert

[Demon]

Page 33, 4.17.1 - Multiplication.

Using * and **, / and //.

Good luck!

Robert

[Tom Gonser]

Exactly the problem.. I have 3 bytes that need to be put into one variable.. this is a 24 bit container that relates a number - the altitude in tenths of meters..

How to get this into ONE variable I can work with is the first issue..

Tom

[Acetronics2]

Hi, Tom

Let's have another view of the problem ...

You get an altitude measurement, ...but what is your sensor ??? and mostly what is its precision ???

I do not know lots of altitude sensors seriously able to give 1 cm on a hundred meters ... 1/10 000 precision, you sure ??? ... !!!

May be a little look here could reduce your number sizes ...and simplify you work.

24 and 32 bits arithmetics can be downloded from Melabs site ... if you really want to keep "ghost" centimeters !!!

Alain