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"C" or "O" input condition is true. If "C," the entire time the input is closed, if "O," the entire time the
input is open. If triggered without a "P," the file will play indefinitely or until another sound is played.
If an "S" is used in the filename, an optional contact closure will be activated when the file is played.
(version 1.5 and later firmware only)
Sample Filenames
"01C.WAV" - This file would play once, when triggered by input #1 closing
"02O.WAV" - This file would play once, when triggered by input #2 opening
"04CP.WAV" - This file would play once, when triggered by input #4 closing and play only while in-
put #4 was closed without repeating.
"07CPR.WAV" - This file would play and repeat, the entire time input #7 was closed
"01OPR.WAV" - This file would play and repeat, the entire time input #1 was open
Compact FLASH Card Loading and Scanning
Once programmed with the desired sounds and correct filenames, the card is inserted into the slot on
the front of the Compact FLASH Digital Audio System. The green LED indicator should begin to flash
indicating that the unit is scanning and loading the files from the card. When the card is correctly loaded
and scanned, the green LED should glow steadily. Problems are indicated by flashes on the red LED indi-
cator.
The contact inputs are debounced by sampling them using a periodic interrupt. The sample rate is 50
Hertz (20 milliseconds). Valid input closures are detected by reading a 0 - 0 - 1 (open, open, closed) sam-
ple sequence. Valid input opens are detected by reading a 1 - 1 - 0 (closed, closed, open) sample sequence.
After the Compact FLASH Card is loaded and scanned, the Compact FLASH Digital Audio System
forces a re-read of its contact inputs by clearing its sample history to activate any sounds associated with
contacts that are already active. Contacts on the optional expansion board read as closed when the board is
not installed, thus sounds assigned to those contacts as closures will play when the Compact FLASH Card is
inserted or the unit is reset.
The card may be removed at any time. In that case, both the green and red LED indicators should turn
off.
The status of the unit while loading and scanning is also displayed via messages sent out the serial port.
Using a PC with "HyperTerminal" or other terminal emulator software connected to the Compact FLASH
Digital Audio System the card loading and scanning messages may be viewed. The serial data format is
2400 baud, 8 data bits and 1 stop bit. Samples of these messages are shown in the Appendix.
Background Audio track
If a sound file is copied onto the Compact FLASH Card with the name "BACKGRND.WAV," this
sound file will play only when no other audio tracks are being played. It will cease playing when the com-
mand is issued to play another sound file. Once that sound file is finished playing, the BACKGRND.WAV
file will resume play from the point where it was interrupted and continue to play until again interrupted.
Compact FLASH Digital Audio System
7
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