SW21-EX17-Freq_Measure-Adv.BS2 - Math & Code

MichelB

Hi, in this program the constant Scale is $200 (512) for "2.0 µs per unit".
How this value (512) has been found? I tried with 65535 / ?

Franklin

How about ATTACHING the program to your next post so we can all see?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
- Stephen

MichelB

Please find attached program.

P.S.: In BSManual-v2.2 page 345, Demo Program (PULSIN.bs2) we can find:

Scale· CON· $200 (512)· ' 2.0 µs per unit

Where and how they found the value 512?

Post Edited (MichelB) : 11/29/2009 1:18:12 PM GMT

Franklin

' -----[noparse][[/noparse] Constants ]-------------------------------------------------------
#SELECT $STAMP
  #CASE BS2, BS2E, BS2PE
    Scale       CON     $200                    ' 2.0 us per unit
  #CASE BS2SX, BS2P, BS2PX
    Scale       CON     $0CC                    ' 0.8 us per unit
#ENDSELECT

If you read the manual the frequency used by the BS2 depends on the type you are using the two frequencies are 2us and .8us and will affect the timing of commands like PULSOUT, baud rate and other timing dependent commands.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
- Stephen

Tracy Allen

Bonjour Michel,

That scale factor is for use with the */ operator.

$200: 512/256 = 2
useconds = RCvalue */ scale ' multiplies RCvalue times 2 for BS2, E, or PE

$CC: 204/256 = 0.796875, call it 0.8
useconds = RCvalue */ scale ' multiplies RCvalue times 0.8 for BS2SX, P or PX

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Tracy Allen
www.emesystems.com

MichelB

Well understood, merci beaucoup Tracy.