GPO Perl or C code?

CTMacGyver · Post by **CTMacGyver** » Wed Mar 26, 2003 12:47 pm

Can anyone point me in the direction of some perl or C code for turning the GPOs on or off?

Thanks in advance!

Jim

Post by **Henry** » Thu Mar 27, 2003 11:06 pm

I'm no perl expert (or even close).

First of all, all you have to do is figure out how to send to the serial port. To turn on a GPO you will need to send 2 or 3 bytes depending on what module you have...

0xFE //Command Prefix
0x56 //GPO on command
1 //for GPO #1

pretty simple really, the hard part is getting perl to format the byte properly..

syswrite DisplayIO, sprintf ("%cX", 0xfe) ; # clear LCD

the above is from a perl example in the downloads section. It clears the LCD screen by sending 2 bytes, once hex and one ASCII. That should help too.

CTMacGyver · Post by **CTMacGyver** » Fri Mar 28, 2003 5:54 am

Thanks for the help.

I haven't had a problem clearing the display or turning the backlight on, but turning on the GPOs or setting the time off for the backlight where it carried the extra byte was confusing me.

I'll post the info here for the next guy.

One of the LCD manuals mentions that the # of the GPO needs to be specified in HEX so:

syswrite DisplayIO, sprintf ("%cW%c", 0xfe, 0x01); #Turns on GPO #1

Jim