Conversion to degrees help

[RFsolution]

Thank you skymath
I will give it a try this evening
I have PBP 2.50 need to patch to 2.50b, what is special in 2.50 regarding to
my conversion problem, dont find anything in the changes log that points to that

This might get you 2 behind the point...

scale = 1024
dummy = position << 6'wont overflow 16 bits, same as *64 but quicker
dummy = dummy * 360 'will overflow 16 bits
result_high = div32 scale 'but doesnt matter here
degrees_whole = result_high >> 6 'same as divide by 64 but quicker

scale = 1024
dummy = position << 6 'wont overflow 16 bits, same as *64 but quicker
dummy = dummy * 36000 'will overflow 16 bits
result_low = div32 scale 'again, doesnt matter here
degrees_fraction = result_low >> 6 'same as divide by 64 but quicker
degrees_fraction = degrees_fraction // 100 'take out the -whole- degrees and leave the fraction

lcdout $fe , 1 , "Degrees:" , DEC3 degrees_whole , ":" , DEC2 degrees_fraction

This should work for a 10 bit ADC, but for a 12 bit ADC, the 2nd chunk will overflow. Changing the 36000 to 3600 and 100 to 10 should let the 2nd chunk work with one digit behind the decimal point, or change 36000 to 9000 and 100 to 25 and you'll get 2 digits behind the decimal point but in steps of .04

And upgrade to PBP 2.50b

[mackrackit]

LONGS!!!!
Look in your manual on the different variable types. 2.5 can do 32 bit +numbers
or 31 bit - numbers. Something like that. The negative takes up a bit.

[Ingvar]

OK, You want to scale a number by a constant factor. This is pretty easy using the "*/" and "**" operators. This way you can save some time since the calculations are pretty easy to do for the processor, no divisions only one multiplication. You can learn more about them here http://www.emesystems.com/BS2math1.htm . A short way of describing them is that "*/" makes an invisible division by 256 and "**" divides by 65536.

Older versions(pre 2.50) can only use WORD sized(16 bits) variables, meaning your result must be 65535 or less.
1024 to 360. Degrees = position */ 90 or Degrees = position ** 23040
1024 to 3600. Degrees = position */ 900
1024 to 36000. Degrees = position */ 9000

4096 to 360. Degrees = position ** 5760
4096 to 3600. Degrees = position */ 225 or Degrees = position ** 57600
4096 to 36000. Degrees = position */ 2250

If you have PBP2.50 you can have your result bigger than 16 bits. 360000 is then possible.
1024 to 360000. Degrees = position */ 90000
4096 to 360000. Degrees = position */ 22500

/Ingvar

[RFsolution]

Thanks Ingvar or should I say "professor Math" !

give it a try this evening