Two buttons muti functions

bennettdan

Hello,
···· I want to be able to have two buttons one up and one down and have it output to only four different outputs. Would this work?

Position···· Var·· byte

Main:
· If ButtonUp = 1 then
Position = Position max 4
Position = Position + 1
Elseif ButtonDown = 1 then
Position = Position min 1
Position = Position - 1
endif
If Position = 1 then
outputA = 1
elseif Position = 2 then
outputB = 1
elseif Position = 3 then
outputC = 1
elseif Position = 4 then
outputD = 1
endif
· GOTO Main

Bean

I think you want something like:

position     Var   byte
 
Start:
  position = 1
  OutputA = 1
Main:
  IF ButtonUp = 1 THEN
    position = position + 1 
    position = position MAX 4
    ' Wait for button to be released
    PAUSE 50
    DO
    LOOP UNTIL ButtonUp = 0
  ELSEIF ButtonDown = 1 THEN
    position = position - 1
    position = position MIN 1
    ' Wait for button to be released
    PAUSE 50
    DO
    LOOP UNTIL ButtonDown = 0
  ENDIF
  IF position = 1 THEN
    OutputA = 1
    OutputB = 0
    OutputC = 0
    OutputD = 0
  ELSEIF position = 2 THEN
    OutputA = 0
    OutputB = 1
    OutputC = 0
    OutputD = 0
  ELSEIF position = 3 THEN
    OutputA = 0
    OutputB = 0
    OutputC = 1
    OutputD = 0
  ELSEIF position = 4 THEN
    OutputA = 0
    OutputB = 0
    OutputC = 0
    OutputD = 1
  ENDIF
  GOTO Main

If the outputs are sequencial on the same port you could just use the shift operator instead of having to set each on individually.

Bean.


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·

JonnyMac

If you keep things zero-indexed (0 to 3 instead of 1 to 4) you can also do this:

Check_Buttons:
  IF BtnUp = 1 THEN
    INC pos
  ELSEIF BtnDn = 1 THEN
    pos = pos + 3
  ENDIF
  pos.2 = 0

In this case the pos.2 = 0 does the same thing as pos = pos // 4 -- without the division.

bennettdan

Thanks Bean I didnt think about turning off the other outputs.

JonnyMac That is a little less code and it should work I cant test it right now my SX blitz is not working after my Three year old assitant technician spilt her Cola on it..lol but the SX48 protoboard survived..

JonnyMac

You should still debounce your buttons as Bean demonstrated in his code. And if you go with the zero index and keep your outputs in a contiguous group (e.g., RB.0 - RB.3) you could do something like this:

RB = RB & $F0
tmpB1 = 1 << pos
RB = RB | tmpB1

The first line clears your outputs; the second sets the correct bit of a temporary variable; the final line sets that bit on the port.

bennettdan

Thanks again JonnyMac
Your code steps the 1 of tmpB1 through the pos variable that way their would only be one output on at a time right?

JonnyMac

Right. If you don't have an SX-Key that you can run in Debug mode, hook up some LEDs and try it. Experimenting is an important part of the learning process.

bennettdan

JonnyMac,
I have an extra prototype board and I plan to solder a ribbon cable header to the SX48 proto board and then run the wires to the prototype board so I can hook up some leds to tes with.
Thanks again

JonnyMac

I am forever suggesting to those interested in the SX to save their pennies and buy the Parallax Professional Development Board. I use it all day, every day, and am never wanting for the ability to create something with the SX. If I do need to use the SX48/52 I plug an old SX Con Carne module into the PDB breadboard and I'm set. I know it costs a couple dollars, but I can tell you from experience that the time and hassle saved by having it handy is worth every penny you spend on it.

bennettdan

What do you mean by the SX Con Carne module I do not know what that is? Is that some type of TQPF to Dip module?