MICRO-TRAK 8000 SETUP
The Micro-Trak is a fully assembled and populated printed circuit board. To use the Micro-Trak, all that is needed is some simple programming, a power source, an antenna, and a GPS unit. The following is a list of steps on how to set up your own Micro-Trak 8000.
You will need a low wattage pencil-type soldering iron with a small tip, some thin solder, and a pair of diagonal cutters. The microcontroller is static sensitive, so use standard precautions. For each item, insert on the component side (white silk-screened side), then turn the board over and solder the leads to the pads on the trace side. Be sure to only solder the correct pad, and do not let any solder touch any other pad or trace. Trim any excess leads with diagonal cutters after soldering each component. The following checklist will be useful to insure all components are properly assembled.
1. Before beginning, consider how the Micro-Trak will be mounted.
2. Install the 18-pin IC socket for U1. Be sure to align the notched end of the socket with the marked end on the silk screen. It may help to temporarily slide J1 into position without soldering to make the socket sit flat on with the PCB. First solder just two diagonally opposite pins of the socket, and check that the socket sits flat on the PCB. Then solder the remaining socket pins. Do not insert the chip into the socket at this time.
3. Install capacitors C1 – C5. (0.1uf, 104). Direction does not matter. If the leads need to be formed to 0.1 inch spacing, be careful not to bend too close to the yellow ceramic material. Bend the leads apart slightly after insertion to prevent them from falling out when the PCB is upside-down for soldering.
4. Install transistor Q1 (2N2222A), which provides Push-To-Talk (PTT) for the radio transmitter. Be sure to orient flat side to match the flat side shown on the silk-screen pattern. Q1 is just above C5.
5. Install voltage regulator U2 (78L05). Be sure to orient flat side to match the flat side shown on the silk-screen pattern.
6. Install ceramic resonator Y1 (10 Mhz), which provides the clock oscillation for the chip. Direction does not matter.
7. Install resistors R1 (8.2K gry-red-red), R2 (3.9K, org-wht-red), R3 (2K, red-blk-red), R4 (1K, brn-blkred),
8. R5 (220K, red-red-yel) which create the 4–bit digital to analog resistor ladder. For each resistor, bend one of the leads 180 degrees at the bulb of the resistor so that both leads are parallel and 0.1 inch apart. Install vertically on the board. Polarity does not matter. Bend the leads apart once inserted to hold in place.
9. Install resistors R7 and R14 (10K, brn-blk-org) using resistor instructions above.
10. Install resistor R8. (2.2K, red-red-red). Use instructions for resistors above. Note: If TinyTrak3 will be used with a radio that does not key via current through the microphone line, such as mobile radios and Kenwood handhelds, R8 will not be needed. If R8 is used, you should not wire PTT OUT to the radio.
11. Install resistors R10 – R13 (1K, brn-blk-red). These limit the current flowing into LEDs D1 – D4.
12. Install glass diodes D5 & D6. (1N4148) The black stripes should be nearest J1. Bend like resistors.
13. Install glass diode D7. (1N4148) The black stripe should be nearest LED D1. Bend like resistors.
14. Install potentiometer R6, (10K, 103) which adjusts audio output level.
15. Install potentiometer R9, (10K, 103) which adjusts carrier detect sensitivity.
16. Install Power Display LED D1 (red). This LED will light when device is powered. Be sure to align the
flat side of all LEDs with the shape on the silkscreen, nearest the top edge of the PCB. The short lead on an LED is nearest the flat side. The LED should be touching the PCB.
17. Install Carrier Detect LED D2 (yellow). This LED will light constant when audio is detected from the radio
receiver, and flash during the quiet time before transmitting.
18. Install GPS State LED D3 (green). This LED will light constant when receiving good (locked) GPS data, and flash when receiving bad (unlocked) GPS data. It will be off when no GPS data is received.
19. Install PTT LED D4 (red). This LED will light when the radio is keyed via PTT.
20. Install female DB-9 radio connector J1. This is the connector with the holes. Wedge the board in between the two rows of solder cups, with the 5 pins aligned with the 5 pads on the PCB. The connector must be completely against the PCB edge. Solder just one pin first, and insure the connector is on straight. Then solder on both sides of the PCB, all nine cups to the pads.
21. Install male DB-9 serial connector J2 as you did for J1. This is the connector with the pins.
Assembly Completion
After all components have been installed, inspect the solder side of the board for poor or cold solder joints. All pads should be shiny and smooth. Inspect for any undesired solder bridges. Use an ohmmeter to be sure power (socket pin 14) and ground (socket pin 5) are not shorted, and have about 3K ohms across them. You can then also provide power to the board (see below), and confirm +5 volts between socket pins 14 and 5. Pin 1 is nearest R14, pin 9 is nearest R4, pin 10 is nearest Y1, and pin 18 is nearest J6. If the board looks ready, complete the assembly as follows.
22. Insert programmed microprocessor U1. The chip is static sensitive, so ground yourself by touching a
large metal object before touching the chip. The rows of pins may need to be bent slightly. Be sure to align the notch on the chip with the notch on the socket, as well as the notch on the silk-screen
(nearest the LEDs). An improperly inserted chip may become permanently damaged. When powered, the green and yellow LEDs should flash 3 times, which means the Micro-Trak is running.
Interfacing
The following are the interface connections for the Micro-Trak, which are needed before operation.
Radio – J1
Female DB-9 connector J1 is used to interface Micro-Trak to a radio transceiver. It is compatible with the radio connector on Kantronics TNC, such as the KPC-3. Connect AUDIO OUT (J1 pin 1) to the radio’s mic input. If the transmitter transmits when the microphone input is grounded (most handheld (HT) radios do, except the Kenwood brand), resistor R8 must be installed, but PTT OUT (J1 pin 3) will not need to be connected to the transmitter. For all other transmitters, PTT OUT (pin 3) will be needed, and should be connected to the transmitter’s PTT input. PTT OUT is grounded when the transmitter is to be keyed. To prevent transmissions over other stations, connect the receiver’s squelched audio out (earphone) jack to the AUDIO IN (pin 5). Also connect J1 GROUND (pin 6) to the radio’s ground. Note: Micro-Trak cannot
decode the incoming packet data. Instead, it just watches for audio energy (voice, data, or static) to hold off transmitting over other stations. Refer to the transceiver’s manual for more information, and look for a section on installing a terminal node controller (TNC) for packet operation, as Micro-Trak is interfaced in a similar manner. J1 can also be used to supply or receive Micro-Trak’s power, via pin 7 and pin 6. J1 also provides a PTT INPUT (pin 8) to allow Micro-Trak to transmit a data burst after the microphone is unkeyed after voice traffic. This input should be grounded when PTT is pressed, and floating when PTT is released. This input is not needed for normal operation. J1 also can optionally interface to a radio’s carrier detect output via the CARRIER DET input (pin 2). To use this option, CARRIER DET should be grounded when the channel is busy. If the radio asserts CD output high when the channel is busy, use the Invert CD option in the configuration program. R9 should be removed, or set to center when using J1 pin 2. In addition, SW1 is available on J1 via pin 4.
Serial – J2
Micro-Trak must be connected to a computer for configuration of call sign and other operating parameters, and then connected to a GPS to receive position data. The male DB-9 J2 serial connector is used for this purpose. J2 pin 3 is used to transfer serial data from the Micro-Trak to the computer. J2 pin 2 is used to transfer serial data from the computer or GPS to the Micro-Trak. J2 pin 5 is serial ground. Both a gender-changer (female-to-female) AND a null-modem adapter will be needed to interface the computer to Micro-Trak. A null-modem adapter swaps pins 2 and 3, and connects pin 5. Use a DB-9 serial extension cable if it is difficult to connect the gender-changer, null-modem adapter, and TinyTrak3 directory to the computer 9-pin serial port. Due to the TTL voltage levels used, some laptop computers may not be able to communicate with the Micro-Trak. If using a GPS that plugs directly into a computer serial port, that GPS can be plugged directly into TinyTrak3’s J2 serial connector. If the GPS does not connect directly into a computer’s serial port, an interface will need to be built. The GPS should have a female DB-9 with GPS serial data out wired to pin 2, and ground to pin 5. GPS serial input is not used. J2 can also be used to supply or receive TinyTrak3’s power. If this is desired, short J7 on the back of the PCB by dropping a
bead of solder across the two square pads. After this, J2 pin 4 will be connected to J3 and J1 pin 7. The GPS must output the $GPRMC sentence or the $GPGGA sentence or both at 4800 baud N81. The $GPRMC sentence provides position, speed and direction. The $GPGGA sentence provides position and altitude.
Power – J3 (also J1 and J2)
Micro-Trak must be powered with an external source of 7-35 volts DC, such as a 9-volt battery, or a 12-volt cigarette lighter plug. Micro-Trak is NOT powered via a computer’s serial port. Power can be applied via J1, J2, or J3. J1 is the most common way to power the TinyTrak3. To use J1, connect pin 7 to positive voltage and pin 6 to ground. To use J2, connect pin 4 to positive voltage and pin 5 to ground. Also, short J7 on the back of the PCB by dropping a bead of solder across the two square pads. To use J3, apply positive voltage to the plus (+) hole, nearest the LEDs, and ground to the minus (-) hole. Only one of the three jacks J1, J2, and J3 should be used to supply power to the TinyTrak3. If power is applied via J2 or J3, the same power will be available on J1 to power a radio. If power is supplied via J1 or J3, the same
power can be retrieved via J2 to power a GPS, if J7 is shorted. Be sure not to draw more current than your supply can handle. At 12 volts, current draw is 6.6ma + 3ma for each LED lit. If desired, the 4 1K LED resistors can be replaced with 10K resistors, which will cause the LED to only draw about 0.5 ma each.
LED Control – J4
This optional jumper is normally bridged on the PCB, but if desired, can be cut, and replaced with a true jumper. This will allow easy disconnection of the LEDs if current saving is important. If desired, cut the trace between the two J4 holes, and insert a 1x2 header.
Primary/Secondary Switch SW 1 – J5
This switch input will select the primary or secondary operating parameters. When left floating, or at 5 volts, the primary parameters are used. When grounded, secondary parameters are used. Whenever this switch is changed, the timers are reset, the Carried Detect LED (D2) will blink rapidly for a short time, and then a transmission will be sent. SW1 is also available on J1 pin 4. This switch input is optional, and can be left unconnected.
Power Switch – J6
J6 can be used to control power to the radio and/or GPS. Micro-Trak can be configured to assert J6 with 5V just before a transmission is sent. After the transmission, J6 will drop back to 0 volts until the next transmission is ready. Be sure to choose a relay that can handle the power requirements of the radio and GPS. A Radio Shack 5VDC Reed Relay (275-232) can be used to control power to a radio that draws less than 1 amp. J6 can only supply 25ma. This output is optional, and can be left unconnected. See the Power Switch section in the Configuration Software.
Serial Power Enable – J7
To bridge serial power J2 pin 4 to Micro-Trak power J3 and J1 pin 7, this jumper on the bottom of the PCB should be shorted by dropping a bead of solder across the two square pads. This will allow the GPS to receive power from the Micro-Trak power source, or let the TinyTrak3 be powered from the serial connector. If serial power is not needed, leave this jumper open.
