2
Features
The PIC18F252 core of the APP-II has 5 channels of 10-bit A/D,
up to 19 digital I/O, and a hardware serial port usable by your
programs. The device has 1.5K bytes of RAM, 256 bytes of
EEPROM, and nearly 16K of program words (32K bytes minus
512 bytes). This processor is much more powerful than, for
example, the older PIC16F87x series. It includes a more
sophisticated interrupt system, an accessible stack, hardware
multiply, and more.
Assembly
Please refer to the enclosed GPMPU28 manual for assembly
instructions. There is only one modification required on the board.
Place a two pin male header in pins 3 and 4 of the ICSP connector.
Leave the other holes of this connector empty. Remember, pin 1 of
the ICSP connector is closest to the DB9 – be careful not to get this
connector backwards.
The two-pin header you install will allow you to select
programming mode or execution mode by placing (or removing) a
jumper on these two pins. With the jumper in place, the APP-III
will allow programming (via the download software). When the
jumper is not present, the APP-III will run your program.
The APP-III is shipped with a test program already on board.
Remove the shorting cap on the programming header and observe
the onboard LED. When you apply power to the circuit, the LED
will blink indefinitely. If this doesn't happen, disconnect the power
immediately and check all connections.
Once the test is successful, connect your PC to the board's
connector. Start a terminal program (such as Hyperterminal, which
comes with Windows). Make sure that the port you want to use is
not in use, and that the complimentary port is also not in use (many
PCs can't use COM1 and COM3 or COM2 and COM4 at the same
time).