[fpc-pascal]Embedded Linux Journal - ThinkNIC Contest

[Jeff Wormsley]

On 05/17/2001 at 12:07 AM Michael.VanCanneyt at wisa.be wrote:

>The only tricky thing might be controlling the bill validator.

I think that can be done fairly easily.  I plan on stripping a keyboard and tieing the relay of the validator to a key (like F6 or some other rarely used key).  So, each bill pulse will just be a keystroke.  There is an enable signal on the validator, and I plan to use the keyboard's scroll lock signal to control that.  There is a brief moment at power up that it is on, but no one should be using it when it is powering up.  When my program is ready to run, I can turn on the scroll lock (I know how to do it in DOS/Win32, shouldn't be difficult in Linux) and the validator should be enabled.  If the ThinkNIC had a serial port, I would use the more modern MDB (serial) validator, but as it is, that would entail buying a USB serial adapter and figuring out how to get USB support to work on the box, which is beyond my abilities.  (There are only USB drivers for about 5 printers included with the package, and several people have had no luck getting USB to parallel port drivers working with it.)  If worst comes to worst, Hagstrom Controls sells a Keyboard to I/O controller that is programmable.  But I would rather avoid the $120(US) it costs to buy such a thing.

Jeff.