Rev2 Timer Board Connector Reference

Rev2 Timer Board Connectors

Connector J1 - Serial Communication
GND	connects to pin 5 of a DB9 Serial RS-232 Connector
Rx	connects to pin 3 of a DB9 Serial RS-232 Connector
Tx	connects to pin 2 of a DB9 Serial RS-232 Connector

Communications Settings: 9600 Baud, 8-Bits, No Parity, Flow control=None

Board Serial Connector

Connector J2 - Power
GND	Common Ground (Negative voltage)
+	Positive power input, +9 to +24 volts

If you are not using the display driver board, a 9 to 12 volt power supply is recommended.
If you are using the display driver, you should use a power supply rated at at least 15 volts.

Annotated Power Connector Photo power connector diagram

Connector J3 - ICSP
1	MCLR
2	VDD
3	GND
4	PGD
5	PGC
6	PGM

The ICSP Connector type is the standard used by Olimex ICSP programmers.

IMPORTANT NOTE:
There are several different pin layouts used for ICSP connectors.
Be sure to verify your programmer uses the right type, or you could damage the chip, the programmer, or both!
Your programmer's ICSP connector must use the pin layout shown here.

Connector J4 - Lane Sensors
GND	Common ground for sensors - connects to all phototransistors
1	Connects to Lane 1 phototransistor
2	Connects to Lane 2 phototransistor
3	Connects to Lane 3 phototransistor
4	Connects to Lane 4 phototransistor
5	Connects to Lane 5 phototransistor
6	Connects to Lane 6 phototransistor

Unused lanes should be left unconnected and turned off in the firmware.

Connector J5 - Finish Line Tower
G	Common ground
Rdy	Connects directly to Ready LED
Res	Connects to (optional) Reset Switch Leave unconnected if you are not using a reset switch
+5v	+5v regulated power for finish line illumination LEDs

The Ready LED comes on (solid, not blinking) when the timer is ready to begin a race. When the race starts, the Ready LED will turn off until the race has completed. You should mount it so that it can be clearly seen by the starting gate operator. If something is wrong, the Ready indicator will blink. This is most often seen when the starting gate isn't closed. The Ready LED will also blink rapidly when the timer is in setup mode, or being configured through the setup software.

The reset switch can be used to force the timer to end a race before all cars have crossed the finish line, without waiting for the timer to time out. This can also be done through the computer software interface if your software supports it, so this switch is often unnecessary and not installed. If used, this should be a Normally-Open (NO) Momentary (push-button) type switch.

More information about this connector is available on the finish line illumination LEDs info page.

Connector J6 - Starting Gate
G	Common ground
Str	Connects to Starting Gate Detector Switch (REQUIRED)
Sol	Connects to (optional) starting gate solenoid driver circuit. Leave unconnected if you are not using a solenoid. DO NOT CONNECT THIS DIRECTLY TO A SOLENOID YOU WILL OVERLOAD THE CIRCUIT AND DAMAGE THE CHIP!

The starting gate switch can be the normally open (NO type), or normally closed (NC type) as long as you configure it properly in the timer firmware. The switch should be installed such that it stays pressed while the gate is closed, and is released when the gate is opened and the cars take off. You must have the start switch, or the timer will have no way to know a race has started.

The starting solenoid is optional, and can be triggered through software to open the starting gate and start the race.

If the gate is not closed before the race ends, the Ready LED will blink until the gate is closed, then go out. You must wait until it comes back on before starting the next race. This short delay is to insure a false start isn't triggered accidentally while closing the gate.

Display Connector

The display connector may be used to directly drive 1-inch high digits, or you can plug in the optional driver board to use large 3-inch digits. Note the "upside down" orientation of the display connector, with pin 1 at the lower right, and pin 16 at the top left. Viewed "right side up" from the front of the board it looks like this:

Display Connector pins
16	Segment G	15	unused
14	Segment F	13	Digit 6 Drive
12	Segment E	11	Digit 5 Drive
10	Segment D	9	Digit 4 Drive
8	Segment C	7	Digit 3 Drive
6	Segment B	5	Digit 2 Drive
4	Segment A	3	Digit 1 Drive
2	Unregulated power to display driver board (+12 to +24 depending on power supply)	1	GND - Common ground connection

The power pins, pins 1 and 2, are only used for the display driver board. They are not used when driving digits directly. Care must be take to insure they do not get shorted.

Details on the display driver board are available here.