BCTRAK VER 1.5 INSTRUCTIONS

This software is written for the PIC 16F628A micro. It is meant to be an application specific
replacement for the PIC program that is normally used with the FreeTrak encoder.
The firmware receives RS232 serial data at 4800 or 9600 baud 8 bit no parity. When it receives a
carriage return or has filled it's 150 byte buffer, the data is converted to a AX.25 unconnected
packet modulated at 1200 baud. The radio PTT is applied, sending 45 flags before send the data.

Configuration:
If the BCTrak has never been configured and powered up with the A:4 (pin #3) jumper open,
the red LED will be blinking. Remove power and close jumper.
You will need to run a serial terminal program like HyperTerminal or similar.
The 4 pin jumper block shown in schematic allows you to reverse data lines (null modem)
by moving jumpers in 90 degrees.
This allows serial communication with either a computer or GPS.
Powering the BCTrak up with the A:4 (pin #3) jumper shorted low invokes the configuration menu.
This version of the software uses the message bit jumpers (PORTB:6,7).
If PORTB:5 are grounding (0) then data speed is 9600 baud else data speed is 4800 baud.
The computer terminal program should be set for 4800-8-1 or 9600-8-1 no handshaking.
You should see this on your computer:

BCTrak v1.5 (c)2011 by OM3BC
Enter TOCALL
>

This is the destination call sign. Enter the call sign and SSID (if any).
This is often set to APRS.
Press <ENTER>.

Next will be Enter MYCALL. Enter your call sign and desired SSID (if any). Example: OM3BC-9.
Press <ENTER>

Next are the DIGI entries (if any).
Press <ENTER> after each one.
There are up to three digipeater entries available.
These are optional and pressing <ENTER> without any data will skip ahead to the
HOLDOFF entry.

The HOLDOFF is a timer which counts down the number of sentences from the GPS. When
it reaches zero it transmits and resets itself to the value you enter here.
Most GPS send once per second so a number like 30 would equal 30 seconds.
The number must be between 1 and 99.

Next it will ask: Compressed Report Y/N?
If you want to transmit mic-e compressed format type Y else type N.
Press <ENTER>

If you choose Y:
It will ask: Enter symbol code - <CR> for default car
Consult with the Mic-E specification for an entire list.
Some common ones are:
    -     house
    >     car (default)
    <     motorcycle
    Y     sailboat
    b     bicycle
    R     rec vehicle
    O     balloon
    r    tower with VHF antenna
    y    house with yagi antenna
Press <ENTER>

Compressed mode requires the GPS send RMC type sentences configured to DDMM.mm
(minutes in hundredths) format.

Next it will ask: Enter tail text (max 32 char. lenth)
You can type a tail text, what will be sent every given transmission which can be
set up in the step afterwards.
Type <CR> for no tail text.
If you set up a tail text, then it will ask: Tail text every X transmission (1-9)
You must type a number from 1 to 9.

You should now see; Successful Configuration, adjust busy detect now
At this time the busy detect circuit is active and it's trigger threshold can be set.
Connect the audio to a radio at normal listening volume and open squelch.
Adjust the BUSY DETECT pot until the green LED comes on solidly and goes out when unsquelched.
This normally gives a reading at PIC pin B:4 of about 1.2 volts DC.

Remove OPTION jumper and power down.
The next time the unit is powered up without the option jumper, it will be in
transmit mode, waiting for data. The first valid GPS datas are transmitted immediately.
The active state of the PTT is signalized with the red LED.
Momentarily shorting the option jumper during normal operation will force a transmission.
Message bits are selected by either grounding (0) or applying +5V (1) to PORTB pins 6
and 7 in the following combinations.
    pin 6 pin 7
        0     0     returning
        0     1     in service
        1     0    en route
        1     1     off duty

If position data from GPS receiver is valid, the green LED is light permanently.

if PORTB pin 3 is grounded, holdoff time is calculated from speed of vehicle acquired from
GPS data. Holdoff time is aproximately:
0        > 2     > 6      > 13    > 27    > 54    > 81           knots
0        > 4     > 11     > 24    > 50   > 100   > 150        km/h
     256      224     112       56       28         14       7     seconds

As this is presently BETA software, please send bugs and other useful info to my email address
at the bottom of the document.

Good luck and 73
Joe Illes OM3BC
om3bc@om3bc.com

schematic, printed circuit board 65x62 mm, silk snap of the board, firmware