How to send one bit at a time

QAH

Hello all! I am using the Basic Stamp 2 homework board and I would like to know, how can I output 1 bit at a time of a 16 bit word variable? I know how to use SHIFTOUT, but that sends all of the data. I need to send data, wait for an input pulse and if it gets it, send another bit. Can this be done? If so, how?

Thanks

Mike Green

You can access the individual bits of a variable by treating it as a bit array. Say you have a 16 bit variable called FOO declared "FOO VAR WORD". You can reference the individual bits by writing "FOO.BIT(i)" where "i" is a value from 0 to 15 (for the number of the bit).

Let's say you have your I/O pin defined as "SIGNAL PIN 6". You can have a FOR / NEXT loop that does "SIGNAL = FOO.BIT(i)" then waits for your input pulse before going on to the next bit.

Ron Czapala

Mike,
·Actually you get "Expected a variable modifier"· using FOO.BIT(I) -·you need to reference FOO.BIT0(i) or .... BIT15(i)

' {$STAMP BS2}
' {$PBASIC 2.5}

 
FOO VAR Byte
i VAR Nib
FOO = %11001001
 
FOR i = 7 TO 0
  DEBUG BIN1 FOO.BIT0(i)
NEXT

Post Edited (ronczap) : 7/16/2009 12:50:57 AM GMT

Mike Green

Sorry, I didn't really try it. Try this instead: FOO.BIT0(i)

Look at the BASIC Stamp Syntax and Reference Manual, pages 85-91.

QAH

Ok. Thanks for that info guys. I have another question reguarding bits. I will ask it here instead of creating an new thread. I am trying to get data from an N64 controller. On a diagram page it said that the controller sends out bits up to 4us wide. Is there a way I can set to recive data from a pulse that quick?

Thanks