Parallax BASIC Stamp 2e Programming Manual page 223

5: BASIC Stamp Command Reference – POLLMODE
POLLIN 0, 1
POLLOUT 1, 0
POLLMODE 2
Loop:
DEBUG "Looping...", CR
GOTO Loop
In this example, the first two lines configure I/O pin 0 as a polled-input
(looking for a high state) and I/O pin 1 as a polled-output (going low if
I/O pin 0 goes high, and vice versa). The third line, POLLMODE, initiates
the polling process and configures polled-outputs to be active. From then
on, as the BASIC Stamp executes the rest of the program, it will check for a
high level (logic 1) on I/O pin 0, in-between instructions and will set I/O
pin 1 accordingly.
If, in the above example, the poll mode was set to 1 (which means
deactivate polling but save configuration) I/O pins 0 and 1 would still be
defined the same way, and I/O pin 1 would still be set to output mode,
but no polling would take place during the rest of the program.
Here's another example that demonstrates mode 1 (deactivate but save
configuration).
POLLIN 0, 1
POLLOUT 1, 0
POLLMODE 2
DEBUG "Polling configured", CR
Main:
POLLMODE 1
DEBUG "No polling allowed here...", CR
PAUSE 1000
POLLMODE 2
Loop:
DEBUG "Polling now...", CR
GOTO Loop
In this case, polling is configured and activated before "Polling configured"
is printed on the screen.
polling is disabled (via the POLLMODE 1 command) and no polling
occurs during the printing of "No polling allowed here..." or during the 1
second pause afterward. Finally, polling is activated again, and since the
configuration was saved (because of mode 1, before) the polling activity
Once we reach the Main routine, however,
BASIC Stamp Programming Manual 2.0c • www.parallaxinc.com • Page 221