Do I need a bitwise calculation?

rdrieder

NEC M300X Projector lamp runtime query says to concatenate a string in Windows Calc in Hex mode, switch to decimal mode and divide by 3600 to get lamp run time. Oh yeah, it's code for an Axcent3. Am I missing something? Any help would be appreciated.

DEFINE_VARIABLE
INTEGER LAMP_STRING[256]
PROJ_HOURS

(* IN THE FIND STRING CODE *)

LAMP_STRING= "$00,$00,$46,$50"
LAMP_HOURS = LAMP_STRING/$E10

PhreaK

To concatenate the returned value you will need to iterate over the characters and add them along with a bit shift. If it's always going to be four bytes this should do the trick:

/**
 * Load 4 bytes of big endian data contained in a character array into a long.
 *
 * @param	x		a 4 byte character array containg the data to load
 * @return			a long filled with the passed data
 */
define_function long raw_be_to_long(char x[4])
{
    return x[1] << 24 + x[2] << 16 + x[3] << 8 + x[4]
}

Otherwise if it's an unknown length you will need to set up a basic iteration.

Once you've got that it sounds like the device is just spitting back the lamp time in seconds, the divide by 3600 then just converts it to hours.

rdrieder

Great idea!

Unfortunately, I'm dealing with an Axcent3. I'm pretty sure Axcess code doesn't have the shift capability.

PhreaK

Ah to easy. Replace the left shift's with some multiplication:

return x[1] * $1000000 + x[2] * $10000 + x[3] * $100 + x[4]

And change it to a define call.

PhreaK

Or as a loop for an unknown length something like this should do the trick:

integer i
integer j
long multiplier
long ret
for (i = length_string(x); i; i--) {
	if (i > 1) {
		multiplier = $100
		for (j = i - 2; j; j--) {
			multiplier = multiplier * $100
		}
	} else {
		multiplier = 1
	}
	ret = ret + x[i] * multiplier
}

*untested

rdrieder

Thanks-got it working

This works:

((x[1] * (256*256*256)) + (x[2] * (256*256)) + (x[3] * 256) + x[4]) /3600

This does not:

x[1] * $1000000 + x[2] * $10000 + x[3] * $100 + x[4] / 3600

Nor does this:

((x[1] * $1000000) + (x[2] * $10000) + (x[3] * $100) + x[4]) /3600

Interesting...

Appreciate your help!