ESP8266 Community Forum

Posted: **Thu May 18, 2017 9:55 pm**

Hey group,
I would like to toggle a flag on a button push.

btn = io(pi,3)
if btn = 0 then
  if flag = 0 then flag = 1
else 
  if flag = 1 then flag = 0
endif

is there a better / simpler way??

thanks in advance
dwight

Posted: **Fri May 19, 2017 12:07 am**

flag=flag xor 1

Posted: **Sat May 20, 2017 3:12 am**

From lightyears ago.
We always used to use the NOT function.
so toggle = ! toggle

Code: Select all

toggle = 1
button "switch", [switch]
wait

[switch]
toggle = ! toggle 
io(po,d2,(abs(toggle))
wait

Toggle wil avry betweem 0 and -1
By using the ABS value of toggle you will be able to set directly an I/O port

Same result as jimg only a bit easier to remember (for me)

Luc

Posted: **Sat May 20, 2017 3:46 am**

If you use an led pin as your flag you can have visual feedback of the state of your flag.
Remember that button interrupt only needs to do something on either the press or release, which is checked in [PRESSED].

Code: Select all

ledpin = 1     'Use ledpin as your flag variable
buttonpin = 0  'Uses gpio00 flashing button by default, change to suit (needs pullup resistor).
interrupt buttonpin, [PRESSED]
wait

[PRESSED]
if io(laststat,buttonpin) = 0 then gosub [TOGGLE]  'else do nothing
wait

[TOGGLE]
if io(laststat,ledpin) = 1 then io(po,ledpin,0) else io(po,ledpin,1)
return

ESP8266 Community Forum

Best way to toggle a flag 0 to 1 and back

Best way to toggle a flag 0 to 1 and back

Re: Best way to toggle a flag 0 to 1 and back

Re: Best way to toggle a flag 0 to 1 and back

Re: Best way to toggle a flag 0 to 1 and back