BYONICS TinyTrak4 User manual

- 1 -
BYONICS
TinyTrak4 Hardware Manual
Version 0.6
http://www.byonics.com/tinytrak4
Overview.................................................................................................................................................................................. 2
Acknowledgments................................................................................................................................................................ 2
Construction ............................................................................................................................................................................ 2
Schematic ............................................................................................................................................................................ 2
Parts List.............................................................................................................................................................................. 3
Parts List.............................................................................................................................................................................. 4
Printed Circuit Board............................................................................................................................................................ 2
Assembly Instructions.......................................................................................................................................................... 5
Assembly Completion .......................................................................................................................................................... 6
Interfacing ............................................................................................................................................................................ 7
Radio – J1 ........................................................................................................................................................................ 7
Serial – J2 ........................................................................................................................................................................ 7
Power – J3 (also J1 and J2)............................................................................................................................................. 8
Jumper JP1 – JP5............................................................................................................................................................ 8
Serial Power - Jumper JP6 .............................................................................................................................................. 8
Serial Level Jumpers - Jumper JP7A & JP7B.................................................................................................................. 8
PTT Control - Jumper JP8 ............................................................................................................................................... 8
TinyTrak4 Adjustment.......................................................................................................................................................... 8
Firmware Updates ................................................................................................................................................................... 8
Troubleshooting....................................................................................................................................................................... 9
Frequently Asked Questions ................................................................................................................................................... 9
Hints, Tricks, & Notes.............................................................................................................................................................. 9
From The N3UJJ.COM Document LibraryFrom The N3UJJ.COM Document Library

- 2 -
Overview
TinyTrak4 is a radio controller similar to a packet TNC, which can transmit and receive signals over a two-way radio. It
can receive and broadcast position reports from a GPS receiver, decode incoming packet tones, is field programmable,
and more. The TinyTrak4 is interfaced to a radio transceiver so it can cause the radio to transmit audio tones, and also
listen to the received audio from the radio and decode and react to that information. The TinyTrak4 can be re-
programmed at any time with a computer’s serial port as new functionality is created or problems are fixed. A common
use of the TinyTrak4 will be an APRS Tracker, which will take position information from a connected serial GPS and
transmit that over the APRS network. With TinyTrak4’s ability to also decode packets, the tracker can also display other
nearby stations on the display of the GPS (when supported), or be commanded from other packet stations. The TinyTrak4
APRS Tracker firmware will support the TinyTrak3 features, such as text, MIC-E, and NMEA output formats, altitude,
speed, and heading reporting, timestamps, burst after voice, time-slotting, and SmartBeaconing. Other TinyTrak4
firmware programs will provide different functionality. The TinyTrak4 microcontroller is not backward compatible to older
TinyTrak circuit boards. All TinyTrak devices have been created by Byon Garrabrant, N6BG. More information can be
found at the Byonics web site at http://www.byonics.com.
Acknowledgments
Thank you to all the testers and users of the TinyTrak4, TinyTrak3, TinyTrakII, and TinyTrak. Without your suggestions
and support, TinyTrak4 could not have been created. Special thanks to Sean Sheedy, AI4ID, Matt Krick, KC7GSA, and
Scott Evans, VK7HSE who each gave excellent help and suggestions during TinyTrak4 beta development. Finally, Extra
Big Thanks to the Wonderful Lara Garrabrant, KD6AYO, who kits and ships all the TinyTrak products.
Construction
Printed Circuit Board
The TinyTrak4 printed circuit board (PCB) is double sided, silk-screened, and solder masked.
From The N3UJJ.COM Document LibraryFrom The N3UJJ.COM Document Library

- 3 -
Schematic
From The N3UJJ.COM Document LibraryFrom The N3UJJ.COM Document Library
Vin
J3
Power I
e1s
1 8pf ~
01
20 MHz
e16
1 1 8pf
vee
vee
L1
10u H
R3 330 R2 330 R6 220K
e1 30. 1uf
r LM335Z
vee
R adio/ Power
J1
Vin
<J-------<J JP6
<J-------<) J
vee

- 4 -
Parts List
Identifier Name
C1,C2,C3,C4,C5,C6,C7,C8,C9,C10,C11,C12,C13 0.1 uf capacitor (104)
C14 0.47 uf capacitor
C15, C16 18 pf capacitor
C17 100 uf electrolytic capacitor
D1 Red T1-3/4 5mm LED
D2 Green T1-3/4 5mm LED
D3 Yellow T1-3/4 5mm LED
D4 Blue T1-3/4 5mm LED (Clear Case)
U1
ATMEGA324P20U (40 pin DIP) microcontroller
programmed with TinyTrak4 firmware
U2 MAX232A (16 pin DIP)
U3 LM2940CT-5.0 LDO voltage regulator
Y1 20.0 MHz Crystal
R1 10K trimmer potentiometer (103)
R2, R3 330 ohm resistor (org-org-brn)
R4, R5, R6 220K ohm resistor (red-red-yel)
R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18 2.2K ohm resistor (red-red-red)
R19, R20, R21 1K ohm resistor (brn-blk-red)
R22, R23 10K ohm resistor (brn-blk-org)
L1 10uH inductor
J1 Female right-angle DB-9 connector
J2 Male right-angle DB-9 connector
JP1, JP2, JP3, JP4, JP5, JP8 1x2 0.1” header posts
JP6 1x3 0.1” header posts
JP7A, JP7B 1x4 0.1” header posts
D5 LM335Z temperature sensor
Q1 MPS2222A transistor
Shunts 0.1” jumper shunts (6)
Heat Sink TO-220 Heat sink
Screw #4-40 3/8” screw
Washer #4-40 washer
Nut #4-40 nut
PCB TinyTrak4 Printed Circuit Board
40 pin socket 40 pin DIP socket (for U1)
16 pin socket 16 pin DIP socket (for U2)
From The N3UJJ.COM Document LibraryFrom The N3UJJ.COM Document Library

- 5 -
Assembly Instructions
TinyTrak4 is a fairly simple construction project that can usually be built in less than an hour. You will need a low wattage
pencil-type soldering iron with a small tip, some thin solder, and a pair of diagonal cutters. You will also need small pliers
and Phillips head screwdriver for mounting U3. Desoldering braid (Radio Shack part 64-2090) may be required to correct
soldering mistakes. The chips (U1 and U2) are static sensitive, so do not remove the chips from the conductive foam, and
follow the steps for installing them carefully. Insert parts 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 batch of
components. The following checklist will be useful to ensure all components are properly assembled. This list is ordered
by component height, which is a convenient way to build because leads do not need to be bent apart to keep them from
falling out, but components can be added in any order. Build slowly and follow the instructions. Look at the photograph
and PCB image above to confirm component placement.
Install 13 capacitors C1 – C13 (0.1uf, yellow, marked with 104). Physical orientation is not important.
Install 2 capacitors C15, C16 (18pf, yellow). Physical orientation is not important. These two should delivered on
cardboard tape, and look similar to the 0.1uf caps above.
Install the 20.0 MHz crystal Y1 (marked with A200). Physical orientation is not important.
Install the 40 pin DIP socket for U1 and the 16 pin DIP socket for U2. Physical orientation is important. Be sure to
align the notched end of the socket with the notch end on the silk screen (nearest J2 on the right hand side of the
PCB). Insert both sockets before soldering, to keep them both flat on the PCB. First solder just two diagonally
opposite pins of the each socket, and check that the socket sits flat on the PCB. Then solder the remaining socket
pins. Do not insert the chips into the sockets at this time. You do not need to trim the short leads after soldering.
Install transistor Q1 (2222A). Physical orientation is important. Q1 looks similar to D5 below. The leads will need
to be adjusted with pliers to fit into the holes. Be sure to orient flat side to match the flat side shown on the silk-
screen pattern (nearest the 40 pin U1 socket).
Install temperature sensor D5 (LM335Z). Physical orientation is important. The leads may need to be slightly bent
to fit into the holes. Be sure to orient flat side to match the flat side shown on the silk-screen pattern (up, furthest
from the bottom edge of the PCB).
Install capacitor C14 (0.47uf, blue, marked with 474). Physical orientation is not important.
Install potentiometer R1, (10K, marked with 103) which adjusts audio output level. Make sure the short middle
lead pokes through the hole enough to be soldered.
Install 2 resistors R2, R3 (330 org-org-brn-gold). Polarity and physical orientation are not important. For each
resistor, bend one lead 180 degrees at the end of the bulb so that both leads are parallel and 0.1 inch apart. Install
vertically on the board.
Install 3 resistors R4 - R6 (220K red-red-yel-gold). Polarity and physical orientation are not important. Bend and
insert like R2.
Install 12 resistors R7 – R18 (2.2K red-red-red-gold). Polarity and physical orientation are not important. Bend and
insert like R2.
Install 3 resistors R19 – R21 (1K brn-blk-red-gold). Polarity and physical orientation are not important. Bend and
insert like R2.
Install 2 resistors R22 & R23 (10K brn-blk-org-gold). Polarity and physical orientation are not important. Bend and
insert like R2.
Install 6 jumper posts JP1 – JP5 & JP8 (1x2). Physical orientation is not important. These posts come as 1 or 2
strips which will need to be cut apart. JP1-JP5 can be cut as 5 1x2 posts or 2 1x5 posts. Insert the short side into
the PCB. The jumper shunts can be placed on the long side to help hold and align the posts. Solder just one pin
first on each strip, and check that the strip is straight and flat. Some users may wish to use right angle header
From The N3UJJ.COM Document LibraryFrom The N3UJJ.COM Document Library

- 6 -
posts. After soldering, a jumper shunt should be placed on JP8 if using a non-Kenwood hand held radio. No
jumpers should be left on JP1-JP5.
Install 2 jumper posts JP7A & JP7B (1x4). After soldering, jumper shunts should be placed on the left 2 pins of
JP7A, and another on the 2 right pins of JP7A. Two more should be placed on the left and right pin pars of JP7B.
Install jumper posts JP6 (1x3). This jumper is normally pre-cut.
Install LED D4 (blue, but case is clear when not lit). Physical orientation is important. Be sure to align the flat or
notched side of all LEDs with the shape on the silk-screen, nearest the top edge of the PCB. The short lead on an
LED is nearest the flat or notched side (square hole). The LED should be touching the PCB. Note that the LED
order on the PCB from left to right is D4, D3, D2, D1. The color order of the LEDs, left to right, will be blue, yellow,
green, red.
Install LED D3 (yellow). Physical orientation is important. Align the flat or notched side as was done for D1.
Install LED D2 (green). Physical orientation is important. Align the flat or notched side as was done for D1.
Install LED D1 (red). Physical orientation is important. Align the flat or notched side as was done for D1.
Install inductor L1 (10uH, brn-blk-blk-gold). Polarity and physical orientation are not important. This component
looks like the resistors, but is larger. Bend one lead 180 degrees at the end of the bulb so that both leads are
parallel and 0.1 inch apart. Install vertically on the board.
Install the voltage regulator U3 (LM2940CT-5.0). Physical orientation is important. This will be mounted with the
heat sink, and the screw, washer, and nut. The heat sink should be between the regulator and the PCB, with the
fingers pointing up. Bend the regulator leads so that the printed text is facing up and the large mounting hole at
the top is aligned with the hole in heat sink and the hole in the PCB and flat against the PCB. Prior to soldering,
add the #4-40 screw through the holes. If the screw is inserted from the underside of the PCB, it will fit in the
case. On the other side, use the washer and nut. Do not over tighten. Mount with screw before soldering leads
Install capacitor C17 (100uf). Physical orientation is important. There is a stripe on the capacitor to mark the
negative side, which should be nearest the center of the PCB through the round pad. Push C17 down as close as
possible to the board to be sure it will fit in the case.
Install female DB-9 J1. This is the connector with the holes. Do not confuse with J2, as these are difficult to
remove. Solder all 9 pins, plus the mounting tabs on either side. The 9 pins do not need to be trimmed after
soldering, but the mounting tabs should be.
Install male DB-9 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 in, ground,
and 5V (the 3 pins of U3) are not shorted together. There should be about 12K ohms resistance between power in and
ground, and about 8K ohms between 5V and ground. You can then provide power to the board and confirm +5 volts at U3
between the center pin (ground) and lower pin, closest to C17 (+5V). If the board looks ready, remove power, and
complete the assembly as follows.
Insert programmed microprocessor U1. The chip is static sensitive, so ground yourself by touching a large metal
object before touching the chip. The 2 rows of pins may need to be bent slightly to be parallel to each other. 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
JP1-JP5). An improperly inserted chip may become permanently damaged. The chip comes pre-programmed
with the diagnostic program.
Insert MAX232A chip U2. 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.
From The N3UJJ.COM Document LibraryFrom The N3UJJ.COM Document Library

- 7 -
Interfacing
The following are the interface connections for the TinyTrak4, which are needed before operation.
Radio – J1
Pin Function Description
1 Audio out Generated packet or other audio tones to be transmitted via the radio microphone jack.
2 Carrier Detect Digital carrier detect state from radio. Can either be active high or active low.
3 PTT Out This line is grounded when the radio should transmit. Connect to radio PTT input.
4 JP1 Optional J1 interface to the JP1 line. Can be an analog or digital input, or output,
depending on firmware.
5 Audio in Audio received from the radio via the earphone or speaker jack.
6 Ground Ground return for power, audio, PTT and all other signals.
7 Power In Power input to the TinyTrak4. Can be 6V to 18V.
8 PTT In State of optional external microphone PTT switch. Grounded during transmit.
9 No connection May be end-user wired for custom features.
Female DB-9 connector J1 is used to interface TinyTrak4 to a radio transceiver. It is compatible with the radio connector
on the TinyTrak3 and Kantronics TNCs, such as the KPC-3. Connect Audio Out (J1 pin 1) to the radio’s microphone input.
If the transmitter transmits when the microphone input is grounded (most handheld (HT) radios do, except the Kenwood
brand), jumper JP8 must be installed, but PTT Out (J1 pin 3) will not need to be connected to the transmitter. For all other
transmitters, PTT Out (J1 pin 3) will be needed, and should be connected to the transmitter’s PTT input. If JP8 is closed,
you should not wire PTT Out to the radio. PTT Out is grounded when the transmitter is to be keyed. To prevent
transmissions over other stations, connect the receiver’s audio out (earphone or speaker) jack to the Audio In (J1 pin 5).
Also connect Ground (J1 pin 6) to the radio’s ground. 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 TinyTrak4 is interfaced in a similar
manner.
J1 is usually used to supply TinyTrak4’s power, via pin 6 and pin 7. Current draw is approximately 50ma, and it can be
feed with a voltage between 6 volts and 18 volts.
J1 also provides an optional PTT Input (J1 pin 8) to allow TinyTrak4 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
Detect input (J1 pin 2). To use this option, Carrier Detect should be grounded when the channel is busy. Some example
radio interface diagrams are available at http://www.byonics.com/.
JP1 is available on the J1 connector at J1 pin 4 to add an optional interface point for that signal. Various firmware can use
this as an option switch, an analog input, or a digital output.
Serial – J2
PIN Function
1 No Connection
2 Primary Serial data in from a GPS or computer
3 Primary Serial data out to a GPS or computer
4 Power out for GPS (Vin or 5V), or alternate power input
5 Ground
6 No Connection
7 Secondary Serial data out to a computer
8 Secondary Serial data in from a computer
9 No Connection
The male DB-9 J2 serial connector is used to connect to a computer, or a serial GPS, or both. The primary serial port is
on pins 2 and 3. J2 pin 3 is used to transfer serial data from the TinyTrak4 to a GPS or a computer. J2 pin 2 is used to
transfer serial data from the GPS or computer to the TinyTrak4. J2 pin 5 is serial ground. Both a gender-changer (female-
to-female) AND a null-modem adapter will be needed to interface a computer to TinyTrak4. 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 TinyTrak4 directly to the computer 9-pin serial port.
From The N3UJJ.COM Document LibraryFrom The N3UJJ.COM Document Library

- 8 -
The secondary serial port is available on pins 7 and 8. A “Y-adatper cable” can be built to separate the primary and
secondary serial ports to separate connectors.
If using a GPS that normally plugs directly into a computer serial port, that GPS can be plugged directly into TinyTrak4’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. If GPS serial input will be
used, it should be wired to pin 3. J2 can also be used to supply or receive TinyTrak4’s power. If this is desired, JP6 can
jumpered to Vin (the right 2 pins) to send in incoming voltage (usually 12V) to the GPS via J2 pin 4. Set a jumper shunt on
the left 2 pins of JP6 to make 5V available on J2 pin 4. When selecting 5V, do not use a GPS that draws more that about
120ma. The TinyTrak4 may get warm when providing 5V to most GPSs. If JP6 is jumpered to Vin (the right two pins),
power can be supplied to the TinyTrak4 via J2 pin 4.
The secondary serial port (J2 pins 7 and 8) can be set for either RS-232 levels, or TTL levels via jumper JP7A and JP7B.
Power – J3 (also J1 and J2)
TinyTrak4 must be powered with an external source of 6-18 volts DC, such as a 9-volt battery, or a 12-volt cigarette lighter
plug. TinyTrak4 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 TinyTrak4. 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. JP6 must be set for Vin to apply power via J2 and 5V out will not be
available on J2. To use J3, apply positive voltage to the plus (+) hole, nearest J1, and ground to the minus (-) hole. Only
one of the three jacks J1, J2, and J3 should be used to supply power to the TinyTrak4. 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, power can be retrieved via J2 to
power a GPS, if JP6 is set properly. Be sure not to draw more current than your supply can handle.
Jumper JP1 – JP5
These jumpers are available for input or output, depending on the firmware loaded. They can be used for analog
telemetry, selection of options, or driving external loads. JP1 is connected to J1 pin 4. JP5 is connected to pull-up resistor
R7.
Serial Power - Jumper JP6
This jumper controls what power is connected to the GPS via J2 pin 4. When the left two pins are connected, 5V is
available on J2 pin 4. When the right two are connected, Vin is available there. When none of the pins are connected (no
jumper) J2 pin 4 is not connected.
Serial Level Jumpers - Jumper JP7A & JP7B
This jumper sets the level for the secondary serial port (J2 pins 7 & 8) to either TTL levels or
RS-232 levels. When jumpers connect the two left and two right pairs of pins on JP7A and
JP7B, the level is set to RS-232. When 2 jumpers are placed between the 2 middle pins of
JP7A and JP7B, the level is set to TTL. Jumpers should NOT be placed connecting any pins
from JP7A to JP7B.
PTT Control - Jumper JP8
This jumper adds the resistor R15 (2.2K) to the radio mic line to allow PTT via the mic audio connector. It should be
closed (shorted) for use with handhelds other than Kenwood. For mobile radios and Kenwood radios, J8 should be open.
TinyTrak4 Adjustment
There is only one hardware adjustment required for proper operation of TinyTrak4. The transmit audio level should be
adjusted at R1 for proper deviation. If using the TinyTrak tracker firmware, use the transmit tones buttons (1200 Hz/2200
Hz/Send Both) in the configuration software to cause the TinyTrak4 to transmit while adjusting. You can listen on a
separate receiver, and start the potentiometer at maximum drive. Lower the drive level until there is a noticeable change in
the receiver. Overdriving the transmitter is a common cause of failure to decode.
Firmware Updates
The TinyTrak4 firmware can be updated at any time to new and improved functionality with just a computer serial port.
This is done with the .TT4 files, which are new programs which can be burned into the main TinyTrak4 chip. See the
TinyTrak4 Firmware Manual for more information.
From The N3UJJ.COM Document LibraryFrom The N3UJJ.COM Document Library

- 9 -
Troubleshooting
Frequently Asked Questions
Hints, Tricks, & Notes
•JP6 is a jumper to GPS power output. It is not a power input.
•TinyTrak4 DB-9 connectors are pin compatible with TinyTrak3, so GPS and Radio/Power cables for one will work
with the other.
•A Null modem adapter and gender changer, or a similar LapLink cable is needed whenever TinyTrak4 is
connected to a computer serial port.
•R6 can be changed to 100K, or even shorted out (0 ohm) to increase audio output level if setting R1 to the
maximum is not enough.S
From The N3UJJ.COM Document LibraryFrom The N3UJJ.COM Document Library