D Flip-flop to Stamp 2

Rosalina1011

Is there away to make a Stamp 2 to perform like a D flip-flop ? I tried every type of coding nothing works

Rosalina1011

@Rosalina1011 said:

Is there away to make a Stamp 2 to perform like a D flip-flop ? I tried every type of coding nothing works. The D flip-flop is a 74LS74

JonnyMac

Seems like you could debounce the input button and then use TOGGLE for the output.

tomcrawford

Must be an interesting situation where you want to use a $40 Stamp to replace a 40 cent ‘74.

Tracy Allen

' This as a state machine
newstate VAR bit
oldstate VAR bit
upchange VAR bit
outstate VAR bit

main:
  oldstate = in0
  do
    newstate = in0
    upchange = newstate ^ oldstate & newstate    ' the XOR ^ detects change, the AND & restricts to low to high
    outstate = outstate ^ upchange.   ' the output toggles only when the input does low to high
    oldstate = newstate
  loop

The input is not debounced, but that is also true of a D flip-flop. A little pause in the loop might work for debounce, just like a small capacitor on the input of the flip-flop.

Tracy Allen

I still love coming back to the BASIC Stamp. It is the cat's meow for BASIC programming skills. Here is the minimalist program, a full version for the BS2pe (or any). The LED is connected to pin p8 and the pushbutton is on p0 with pullup.

' {$STAMP BS2pe}
' {$PBASIC 2.5}
oldstate VAR Bit
newstate VAR Bit

DIR8=1        ' output for led
oldstate=IN0     ' input for pushbutton
DO
  newstate=IN0
  OUT8=newstate^oldstate&newstate^OUT8.   ' logic for D flip-flop, execution left to right
  oldstate=newstate   ' update the state machine
  PAUSE 10     ' for debounce, too much, too little?
LOOP

Buck Rogers

@tomcrawford said:
Must be an interesting situation where you want to use a $40 Stamp to replace a 40 cent ‘74.

It is. I would do things in reverse. Use the Stamp to configure the 40 cent '74. And produce an output.

Never mind the fact that there are still four families of bobcats making themselves at home on the backlawn of Parallax.