Time counter (20 hours)

Pierre20

Hi

with BS2

How can I make a time counter of 20 hours.

Exemple: I want that when 1 is high for 20 hours, a buzzer turns on.

Thank you

Mike Green

A PAUSE statement can produce maximum delays of about a minute. By putting a PAUSE in a loop, you can produce longer delays. Unfortunately, the Stamp can't do anything else while it is waiting although your program can test an I/O pin. 20 hours is 1200 minutes, so you could have a program somewhat like this:

testInput PIN   1
theBuzzer PIN   2
minutes  VAR  WORD

input testInput   ' make sure pin 1 is an input
startOver:
low theBuzzer   ' make sure pin 2 is a low output
minutes = 0   ' start the 20 hour interval
waitForMinute:
pause 60000 ' wait for a minute to pass
minutes = minutes + 1   ' keep count of minutes
if testInput = 0 then goto startOver  ' if test input turns off before 20 hours, start over again
if minutes < 1200 then goto waitForMinute
high theBuzzer  ' 20 hours has gone by with test input always on
pause 10000 ' let buzzer sound for 10 seconds
goto startOver

Note that this doesn't take care of the case where the test input goes off briefly while the Stamp is waiting for a minute to pass. You may need external hardware for that sort of situation. It's possible to use shorter "ticks", but you start running into accuracy problems.

PJAllen

Using precision components (R, C), you could make a long period oscillator with a 7555 and count its transitions. Might be advantageous to use SLEEP, too.

[Something or other about some blasted thing from ehkss-mawss will likely follow.]

Post Edit -- A super low-power CMOS crystal counter/divider, lots of ways to make it happen.
** I'm violating my policy of not making suggestions. I'm back-sliding, must... stop. **

Pierre20

PJ Allen wrote: »

Using precision components (R, C), you could make a long period oscillator with a 7555 and count its transitions. Might be advantageous to use SLEEP, too.

[Something or other about some blasted thing from ehkss-mawss will likely follow.]

Post Edit -- A super low-power CMOS crystal counter/divider, lots of ways to make it happen.
** I'm violating my policy of not making suggestions. I'm back-sliding, must... stop. **

Thank you for your help. I will try the both.