Basic electronics soldering skills and component identification are required to construct the kit if you order it unassembled.
You can download the complete printable manual in Adobe PDF format here.
You can also get a Timer Board Component Identification Guide with photos showing each part.
Rev2 Annotated Parts Placement Guide
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| Parts List | |||
|---|---|---|---|
| ID | Part | Part Type | Purpose |
| IC1 | 7805 | +5 Volt Voltage Regulator IC | voltage converter and power regulator |
| IC2 | MAX232 | RS-232 Level Line Driver IC | Serial Communication |
| IC3 | PIC16F877A | PIC Microcontroller IC | Processor (ALWAYS use a socket!) |
| C1 | 220uF 25v | Electrolytic capacitor (Polarized) | Power Supply (unregulated side) |
| C2 | 100uF 16v | Electrolytic capacitor (Polarized) | Power Supply (regulated side) |
| C3 | 100nF (0.1uF) | Monolithic capacitor (non-polarized) | Power filtration (0.1uF = 100nF) |
| C4 | 1uF | Electrolytic capacitor (Polarized) | for the MAX232 |
| C5 | 1uF | Electrolytic capacitor (Polarized) | for the MAX232 Note this polarized capacitor is reversed from the rest |
| C6 | 1uF | Electrolytic capacitor (Polarized) | for the MAX232 |
| C7 | 100nF (0.1uF) | Monolithic capacitor (non-polarized) | (0.1uF = 100nF) for power filtration |
| C8 | 1uF | Electrolytic capacitor (Polarized) | for the MAX232 |
| C9 | 1uF | Electrolytic capacitor (Polarized) | for the MAX232 |
| C10 | 100nF (0.1uF) | Monolithic capacitor (non-polarized) | (0.1uF=100nF) for power filtration |
| C11 | 22pF | Monolithic capacitor (non-polarized) | Goes with the crystal |
| C12 | 22pF | Monolithic capacitor (non-polarized) | Goes with the crystal |
| Q1 | 20MHz XTAL | Crystal (Parallel Cut) | Clock source for CPU the 16F877 requires a parallel cut crystal |
| D1 | 1N4004 | Diode | Reverse Voltage Protection |
| D2 | 1N4004 | Diode | ICSP Power Isolation |
| R1 | 470 ohm | Resistor | current limiting resistor for Ready LED |
| RN1 | 10k x 9 Resistor Network | nine 10k-ohm resistors in a single inline strip | Pull-Up resistors for inputs |
Rev2 board fully assembled
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Front view of Rev2 bare board
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Underside view of Rev2 board
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Rev2 Board Schematic
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This is a summary of the Connectors. For more details see the full Timer Board Connector Reference
| 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 |
| 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. | |
|
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 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 |
| 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 |
| Display Connector | |||
|---|---|---|---|
| 1 | GND - Common ground connection | 2 | Unregulated power to display driver board (+12 to +24 depending on power supply) |
| 3 | Digit 1 Drive | 4 | Segment A |
| 5 | Digit 2 Drive | 6 | Segment B |
| 7 | Digit 3 Drive | 8 | Segment C |
| 9 | Digit 4 Drive | 10 | Segment D |
| 11 | Digit 5 Drive | 12 | Segment E |
| 13 | Digit 6 Drive | 14 | Segment F |
| 15 | unused | 16 | Segment G |
Note the "upside down" orientation of the display connector. Viewed "right side up" from the front of the board it looks like this:
| Display Connector | |||
|---|---|---|---|
| 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 |
Details on the display driver board are available here.
