Serial Secrets for PocketPC's

PDA2k Pinouts
Samsung i700 Serial
i700 KB/Power
i700 Audio Pin Outs
Jornada Pin Outs
Absolute Minimum
Double Headed Cable
USB Pin Outs
Combo Cable
36xx Series Pins
38xx Series Pins
Axim Pins
"RJ" Serial System

I've been battling with manufacturer's dumb decisions about accessory cables included with well designed tiny compact devices for years.

When I got my first digital camera, the tiny Kodak DC20, it's serial cable alone weighed more and required more storage space than the camera itself.  In some cases, cables for delicate devices look like they came out of the prop department for a 30's Frakenstein movie, big enough to power all of New York City.  It's rare to encounter any current device manufacturer who understands the need to minimize and streamline all components of their systems to make them as portable as possible.

The Jornada's serial cable is not the worst, but far larger and more expensive than it has to be. My approach to dealing with multiple connection issues is to set up all of the computers that I will be connecting with with easily available and inexpensive standard cables and then minimize a single adapter for the device that will allow it to connect with a minimum "carry weight"

This approach also allows future connecting to unexpected devices as simple and easy as possible, with either standard cables that I have with me or that can be found at almost any electronic store.

USB Mini Connector and Power

PDA2k Pinouts (Serial, USB, Power)

The following are my oberseravtions and no warranty is made as to it's accuracy... use the following information at your own risk.  The following may be relevant for other iMate devices, but I have no evidence of any kind that they use the same connectors and/or pin sequences.

The PDA2k uses a connector that is similar to the current IPaqs, but is wired very differently... DO NOT USE IPAQ CABLES AND CONNECTORS with the iMate Devices as they use totally different pin assignments incuding power input differences which may destroy your device if you do!

If you intend to make custom cables, I strongly recommend using premanufactured cables and modifying them to meet special needs as the soldering demands connecting directly to the connector solder lugs are high along with the dangers of leaving accidental connections within the connector shell that may destroy your device.  I recommend the "PDA2k Serial Sync" cable from Expansys for most needs as it incorporates a standard mini coaxial power jack into the shell that allows using common PPC power supplies such as those for the Ipaq series.

The image shows a "minimal" serial cable created from the PDA2k "Power Adapter" available at Expansys for $14.  It uses the "RJ Serial" connector system that I have been using for almost two decades that continues to serve me well, especially in mobile environments. My "carry kit" contains a variety of connectors that run from DB9 and DB25 connectors, to nulmodem modules, Mac serial connectors, multiple PDA adapters and even a few camera serial connectors.  The Black Cable is the Expansys "Serial Sync" cable, shown to underscore that custom cables can achieve a significant reduction in size, weight and flexibility.

The following pin numbers are derived by looking into the connector on the PDA2k lying on it's back screen up.  Note that the power connections use multiple pins to distribute the charging amperage load to prevent overheating.
PDA2k Pinouts

PPC Connecto
Viewed L-R
Screen Up











(1-4 pins for






Ring 1
Ring 2

The PDA2k audio connector is a "subminature audio" 3/32" diameter jack but with a total of four connector rings to provide stereo output.  These four conductor pins are both hard to find and wired differently for different devices, but in the case of the PDA2k, the additional stereo channel is achieved by dividing the base (ground) ring of the three connector plug into a separate ring connector for the left audio.

This means that "standard" monoral cellular headsets using the same diameter pin with only three connectors can be used with the PDA2k for any use that does not require stereo such as talking on the phone, recording and listening to voice notes, listening to audio books, etc.  This is beneficial since decent wired headsets can be found for prices in the low teens and sometimes less than $10.

An educated guess would indicate that the first four pins are audio connections, but I have not tested this as it is simpler to use the audio jack on the device.  It would make sense so that it could be used in a "hands free" carrier with speakerphone.

I would also assume where the audio jack on the top disables the speaker, using the audio connections on the 22 conductor connection might leave the speaker active.

I would request that anyone who has additional information or corrections to the above contact me so that this page can be corrected.

Samsung i700 Serial Info

The following info originated from the discussion on page two of the thread at which includes pictures and other additional tech info.

One note... the i700 does not ship with a serial driver... you _must_ use the propritary serial driver that ships with the cable from  Note that this connector uses circuitry to boost signal levels which my testing has shown to be unnecessary for short cable runs.

Connectors of this type can be "popped" apart easily.  On all of the Samsung plugs, sliding a blade between the metal shield and outer case will separate the halves and most after market plugs have retainer "tabs" on the outside of the halves that can be spread with a small knifetip while separating.

i700 Serial
(looking at the i700 connector plug pins with the retainer hooks pointing up.)

    |-------------------- gnd
    ||------------------- rx
    |||------------------ tx
    |||  |--------------- ri
    |||  ||-------------- cts
    |||  |||------------- dtr
    |||  ||||------------ dsr
    |||  ||||    |------- vcc (pwr +5v see notes)
    |||  ||||    ||------ gnd
12  3456789|1234567  89
||  |||||||||||||||  ||

i700 KEYBOARD connector (three wires... USB???)

     |-Grn (Tx)  |-Red  (VDD or VDO printed on CB)
     |           |
     |           ||-Gnd
12  3456789|1234567  89
||  |||||||||||||||  ||
    |--res 44.5kohm--|

i500 POWER connector (works, but no charge indicator)

                10k   (10k resistor between pins 5,6)
12  3456789|1234567  89
||  |||||||||||||||  ||

i700 12v charger (w/charge detect circuitry)

#9 = +6v   blu
#8 = +.66v blk
#7 = gnd   blk
#6 = +4.2v red+yel
#5 = +1.5v grn

                |--------- +1.5v grn
                ||-------- +4.2v red+yel
                |||------- gnd   blk
                |||  |---- +.66v blk
                |||  ||--- +5.9v blu
                |||  ||
12  3456789|1234567  89
||  |||||||||||||||  ||

Additional i700 Power Notes

When Samsung Auto Adapter is attached and phone is OFF, moving between cells will turn PHONE ON (also charging is detected and unit will follow "AC" power off settings)

Using this (non Samsung) adapter as wired above (i500 charger,) the device will follow the "BATTERY" power off settings.

When the i500 auto adapter is used, phone will remain off when moving between cells (charging is NOT detected)  Because charging is NOT detected, the device will power off based on the "Battery" power off timer settings  ...a real pita when using it for GPS

i700 Audio Jack Pinouts

A quick look with a tester first didn't turn up much information, but I'm glad that I persued it again after giving up because it appears that they have accomplished something pretty damm neat

The connector is founded on a 2.5 mm (mini) audio jack plus the addition of a conductive collar ring around the base of the plug...

Initially, I assumed that this outer collar was ground and _nothing_ made sense... shifted gears and reset this assumption that possibly the base of the 2.5 pin was ground and things fell quickly into place.

tip = mike
ring = left audio
base = ground
outer ring = right audio

The brilliance of this is that _any_ standard monoral headset now being sold with a 2.5mm plug should work _without needing an adapter!_

I've used many inexpensive cellphone headsets and they work without a hitch, _including_ using it for notes recorder input, so, finally, a ppc with the capability of using an external mike.

How the "button" works, don't have a clue... assume that it is a signal or tone sent through the mike circuit.

Additional i700 "Clues"

gpio gps


APN Manager


Jornada 5xx Serial Info

When the "new" of the Jornada finally worn off... I attacked two of the Jornada's $30 serial cables to reduce their "carry weight" with the following findings that may be of interest to other techies.

Connector pins are as follows (note, colors should, but may not match)  The Jornada connector had no visible number or start markings, so the Jornada pin numbers below are looking into the unit (female) opening with the Jornada face up and counting from left to right.

There is one tiny clue that can provide valuable information for both the serial and power connector.  The Jornada internal connections are gold plated traces directly on the Jornada motherboard, and using a good light and magnifier, you can see that one connector on the serial side and one on the power connector is a fraction of a millimeter longer than the others.  These two connections are signal ground and power minus on the theory that these pins will connect first and provide a ground safety.

The Jornada pins 1-4 are USB and most, but not all, of the remainder for serial with pin 4 being used by both serial and USB (The only visible marks on the connector and shell are "DDK Thailand A")
Jornada 54x Serial Cable Pinouts

Anyone know what the Jornada pins 7 and 12 are? (Is one Carrier Detect?)

Cutting the Connector Fat

Better yet, a very close exam of the Jornada end connector disclosed that it was not an injected molded cover as I first thought, but two plastic shells that can be snapped off to expose a pc-board wire connector.  The shells are spot glued together

That meant that a single serial cable can be converted to a custom serial/USB unit for the serious minimalists out there.

The first conversion was an all out attack on size and eliminated the "cable" entirely.  Two lessions were learned from this design.  First, a few inches of flexible cable are desirable to remove any stress on the edge card socket on the Jornada itself.  without it, the "Walnut" design below could not easily be "handled" during a connect session.  The second was that the "Walnut" was too small and I subsequently lost it in one shuffle or another.

The serial cable pins are fully populated so that a single cable provides the fundamentals for both a serial connection and a USB connection as well.  (I havn't seen the USB cable, but I did note that the USB cradle only populates pins 1-4)

This concept allows the user to travel with a minimum connector and leave affordable cables at each work location or even obtain easily available standard cables if the need for a connection unexpectedly arises at a location without available cables.

First Project... too small... already lost it ;-)
This was not an easy project, but the HP end of the original cable now has a minimal DB9 plus a USB connector in a package about the size of a walnut.

If you elect to proceed with a similar project, do so at your own risk.   While the information here is as accurate as possible, you accept full responsibility for any damage that may come from your mistakes or from mistakes or misunderstandings of information posted on this page!  If you build this unit, please do not attempt to attach both serial and USB cables at the same time.

The image of the handbuilt connector unit above shows both the serial DB9 female connector (black, lower right) as well as the square (white) USB socket.  The above prototype has been successfully tested using both a serial and a USB connect sessions.  The layout shown above is functional but I would change it significantly for a molded production unit for an improved appearance as well as several functional discoveries found during testing.

Evolving to Something More Practical

The above turned out to be too small.  The short story is that I have already lost it, but the other truth was that since standard cables with standard connectors were the norm, the forces on the Jornada connector made it necessary to use the above connector only when the PPC was placed on a firm surface to avoid stress on the physical connection.

The second conversion design had another goal and retained about a foot and a half of cable for stress relief plus the ability to easily connect to devices such as routers without needing additional cable.

Because I seldom used the USB connector, I eliminated it, but a year of Jornada use underlined the fact that I often needed a standard serial connector in addition to the null modem "Sync" cable, so I built a single cable that had both, using the female/male logic to identify which was which and did so in a package that was about a third of the size and weight of a standard serial sync cable.

Double Head sync/serial Cable

The "female" side above retains the factory wiring for attaching to a PC as a nul modem "Sync" cable, but the male on the oppsite side is wired to provide a standard male DB9 serial port wired per the table above.

The male side should be ready for uses such as GPS receivers, cell phones and other standard serial devices.  In addition to serial sync connections, I have found that the female nul modem wiring is already correct for many serial devices such as routers who's connectors are wired to use null modem cables.

To round out the flexibility, I always carry a matched set of DB9 "gender changers"  and a db9 to db25 converter which normally cover all wiring circumstances.

Note also, that the above connector genders match the "standard" DB9 serial connectors on most computers and serial devices... i.e. the female will plug into a computer for syncing or other data/terminal connection, and the male will connect to most devices that would normally connect to a desk or laptop... modems, gps, cellphones, etc.

After wiring, the two connectors were joined back to back by the crude but effective application of hot glue.  In addition, the metal "shells" of the connectors were removed by simply snipping off the grommet holes that served as rivets to hold the halves together and the two molded plastic inserts were secured together with glue as well.

Some tips from this experience;

After you separate the plastic case halves, cut the cable about 2-3" from the strain relief and gently extract the colored strands from inside the braided shielding.  Unless you are very good at soldering on a previously populated circuit board, you want to avoid as much work on the CB as possible, so don't desolder the wires from the connector CB board.  (I did, and should not have)  If there is solder in the empty connection holes for pins 1-3, you will need a solder sucker to clear them.

De-solder only the braided shield wire from the connector CB.  Your goal is to connect the existing wires from the CB to a female DB-9 connector.

Take a bare DB-9 connector and with a metal shear or strong pair of sissors, cut the mounting holes off of the flange as close as possible to the connector body.  You will then be able to part the metal halves with a knife or small screwdriver.  When the metal shell is removed, you will find that the plastic body can also be parted, but do so only far enough to glue the halves with a good glue.

Cut an additional 6" length from the remaining serial cable and extract the brown wire, cut it in half and and solder one piece to pin 5 of the DB-9 connector then connect all of the remaining wires from the CB per the table above.  Note, that you will also need to bridge pins 1 and 6 on the DB-9.  Note, also, that the colors will probably match but may not, so test!

"Mini" USB Charger Pin Outs

Since the increased use of the "standard" mini usb connector to provide both sync and charge connections, thought I would post the following info which relates to the charging use of this type cable/connector.

As far as I can determine, there are only two "standard" mini usb connectors in addition to a raft of other small propritary usb connectors.

The larger of the two "standards" has five "pins" and the smaller has four.

The mini usb five pin connector plug looks like;

5 Pin Mini USB Pinouts
| |       | |
\ | | | | | /
  | | | | |
  | | | | |
  | | | | |
gnd | dat +5v
      \pwr sense?
(Viewing the connector end of a mini usb cable)

It is important to note that many if not MOST 5 pin mini usb cables DO NOT connect the fifth pin to the USB +5v pin in the USB A connector.  This means that even if a cable appears identical to the charging cable that ships with a device using this connector, it may not work to provide power to the device.

The other end of the cable (USB A male, looking into the connetor on the end of the cable) appears;

    |     |--usb +5v
  | _ _ _ _ |

where the right-most pin shown above is USB +5v.

Using the above information, it's also easy to build a short adapter cable which will allow the use of a charger using the coaxial power plugs found on most pocketpc chargers such as the Ipaq series chargers... again, a miswired charger connection can destroy an expensive device, so do so at your own risk.

Some of the newer PPC's are being shipped with only a "Mini USB" I/O connector in place of common propritary multipin connectors that have dominated the PPC's since their introduction.  While this is a step toward "standardization" it still obsoletes allmost all connectors and adapters collected over the years.

The closest thing the ppc community has come to standardization is the 4x1.7mm barrel power connector used by the original Ipaqs.

It was then a simple matter to add an inline 4mm jack to a spare mini connector.  These are available from Altex part# 262...suggest calling the San Antonio Store.

USB Pin Outs

The female USB B connector (may be hard to find... you can scrounge one from a dead USB device or DigiKey has them) connects to the first four pins of the HP 54x connector as follows.  The numbers shown match the HP edge connector positions and may not match standard USB pin numbers.  The connector is shown from the BACK side (away from the plug receptacle)

/ 1 2 \
|     |
|_4_3_|view from behind connector

Attach another length of brown wire to pin 4 and attach pins 1-3 to the corresponding spots on the HP connector CB.

Solder the three brown wire ends together and insulate.

Thoroughly test the connections to assure that they match the above and test all pins to assure that none of them are bridged to another or the ground bar.

fwiw,  pin 1 is +5v, pin 2 is "data-," pin 3 is "data+," and pin 4 is Ground.

Time to run a preliminary connection test between the HP and desktop.  In both cases, power the HP down, insert the edge connector,  attach a standard serial cable to the DB-9 and then plug it into the desktop.  The HP should power up and connect.

Disconnect, power the HP down, connect a standard USB cable and repeat.  Note... there may be some ActiveSync issues switching to USB.

When done, glue the connector shells back over the CB.  The half with the two small ridges should be on the same side of the CB as the connecting pins.

The final step is to physicall mount the connectors to the top shell half.  I recommend that the connectors be oriented as shown so that it is possible to connect either cable with the HP either lying on it's back or propped up resting on the new connector.

I use a hot glue gun, but you may have a better option.  I like the hot glue approach primarily because of ease and availability, but also because it is easier to remove the glue if necessary.

Twist the wires on each connector together, then lay a bed of glue on the top shell and bed the DB-9 facing to the left as shown above.  The DB-9 should be mounted on the side away from the HP power connector since the smaller USB connector is easier to position over the power cord.

Note, also, that the DB-9 needs to be far enough away from the edge connectors to provide space for the mounting lugs that exist on all standard serial cables.

Do the same with the USB connector on the other side.  On this side you will need to keep the USB connector high enough to clear the HP power cord connector with the new unit plugged in.  When the glue hardens, fill in the space between the connectors, re-enforce the bond between edges and smooth out the final fill.

If anyone has gone into the 540 case, I would be interested in information on possible connection between the power jack + pin and any pin on the interface side.

Now the Ipaq (36xx series mod... 38xx table below)

Ipaq 36xx Series Combo CableInside View (Per Request)

Navstation's GPS capabilities finally spurred me to finish modification of the $19 Radio Shack USB Ipaq "Power Tip" part# 25-948

The original RS part is a USB sync/charge combo cable despite the package description that appears to indicate that a separate power supply is required, it does charge from a usb connection.

It does have a jack to accept the 36xx series or Rat Shack charger, and it does charge the Ipaq from a usb connection alone. Note, an additional USB A-B cable is needed but allows you to easily
customize the length to meet your needs.

The Ipaq connector on this unit can be disassembled and customized (assuming you have the skills and itch ;-) to add a serial cable connection.  The solder lugs in the Ipaq connector are large enough to easily add connections.

The finished unit provides significant flexibility in a small package.

USB Sync
USB Power
Serial Sync (Female DB-9 - null modem)
Serial Port (Male DB-9)
External Power port (i.e. when using a serial GPS unit plus a standard 36xx power supply)

The Ipaq end connector disassembles by lifting the shell cover off of the two tabs on the bottom of the connector with a small blade and pushing the wire into the connector, then removing the metal shells by popping them off of the small tabs. (note the orientation for re-assembly)

The black plastic main case on the other end separates using "standard glue popping techniques."

I elected to desolder and discard the inline connector inside the main case and solder the new cable directly to the CB and DB-9's

Took a while, but realized that old Laplink parallel transfer cables contained 12 conductors in a suitably small cable.

3 feet turns out to be a good length to assure that the connections will not constrain a hand held pocketpc connected to GPS, routers, cellphones, etc.  My Jornada dual serial cable is 18" and works in most cases but could be an issue with a gps or cell connection.

Standard DB-9 shells were separated, the back half used for a 9 hole drill template through the plastic shell, then the front half with pins were epoxied onto the case with the solder lugs ready to connect inside the case.

The "Carrier Detect" line is used by both the usb and serial line apparently to trigger a sync wakeup... I have yet to have time to persue this but think that, since the connection appears to be to be protected by a transistor, should be possible to connect to the serial pins as well.

Fun, fun, fun,
Ipaq 36xx, 37xx Connector Pins
From This very useful  Data Page
Pin# db9
Use Descrip
r V_ADP  AC adapter power in
br V_ADP AC adapter power in
3 4 gy DTR RS-232 Data Terminal Ready
4 5? bk GND Power ground
5 8 pk  CTS RS-232 Clear To Send
6 7 u RTS RS-232 Request To Send
7 3 or TXD RS-232 Transmit Data
8 2 wt RXD RS-232 Receive Data 
9 1 y DCD RS-232 Data Carrier Detect
gr GND Power ground
bu UDC_P USB positive data signal
pr USB_N USB negative data signal

FG Frame Ground

FG Frame Ground

FG Frame Ground

Connector pin numbers Looking at the bottom of the Ipaq placed face up on flat surface.

 2  4  6  8  10 12
 1  3  5  7  9  11

Note that since Compaq elected to use this connector with such tiny connector strips, they had to use two pins for each of the power connections... two each for 5v+ and two each for power ground.

iPAQ 3800 Series Pin-outs:
This includes all models other than the 36xx & 37xx series as of this writing in Nov 2005

With the advent of the 3800 series, HP/Compaq changed the sync connector on the bottom of their units to a similar, but smaller cable connector  The new connector is not interchangable with the original 3600 series connector.

Several Ipaq models (notably the 19xx series) sold since the 3800 do not have serial circuitry on the motherboard and therefore cannot communicate via a serial cable.

Also, some other PocketPC's such as some of the IMate brand use the same connector but they are wired completely unlike the Ipaq connector.  Plugging one of these cables into your device could potentially destroy your Ipaq and vise/versa!
  Pin 1 V_ADP

  Pin 2 V_ADP

  Pin 3 V_ADP

  Pin 4 V_ADP

  Pin 5 Reserved - Do Not Use
  Pin 6 RS232 DCD

  Pin 7 RS232 RXD

  Pin 8 RS232 TXD

  Pin 9 RS232 DTR

  Pin 10 GND

  Pin 11 RS232 DSR

  Pin 12 RS232 RTS

  Pin 13 RS232 CTS

  Pin 14 RS232 RING

  Pin 15 GND

  Pin 16 No Connect - Do Not Use
  Pin 17 USB Detect

  Pin 18 No Connect - Do Not Use
  Pin 19 USB - UDC +

  Pin 20 No Connect - Do Not Use
  Pin 21 USB - UDC -

  Pin 22 GND

  Shield Tied to Ground

Axim Serial Pinouts

The pin numbers listed below are arbitrary as there were no pin markings on the 40 pin connector for me to reference.  Looking at the connector on bottom of the Axim with the device lying on it's back, the pins are numbered left to right and noted as being either top (screen side) or bottom row of connect surfaces within the connector.  Conversely, looking at the cable end connector, the pin numbers would be right to left.

The Dell part number(s) for the serial cable are 01Y239 (on the package) 5Y054 (on the invoice) or  SKU# 310-3474 for $19
Fnct  Color Pin(s)
txd grey Bottom-10
rts  red  Bottom-9
dtr  brn  Bottom-8
dcd  yel  Bottom-6
rxd  grn  Bottom-5
cts  org  Bottom-4
dsr  blue Bottom-7
pwr  purp Top-10
gnd  shield Top-1, 15, 20
Bottom-1, 3, 11, 14, 17, 20
sel  blk  Top-14

There is a small "module" about 4" from the Axim connector with snap together halves that can be easily opene with a small knife or screwdriver that exposes the circuit board shown below.

The Sipex SP3243ECA chip shown is described as an "RS-232 Converter" which would seem to indicate that the Axim does not have complete RS-232 circuitry on the motherboard.  While the text describing the pads is hard to read (the cb on the right is just over half an inch high) the markings match the sequence in the table above.  Additionally, the top of the left image matches the right side of the right image.

The use of the above chip and circuitry appears to meet a "standards" rather than technical need.  The RS-232 standard specifies 12volt signals where the base PPC uses 5 volt circuitry, so the above apparently only boosts the 5v signals provided from the PPC to the standard 12v signal level.

Testing has confirmed that connecting serial communications directly to the PPC connector on the Axim and i700 will provide serial communications to and from most serial devices.

There are about 25 other descrete surface mount components, most of which appear to be resistors or diodes and one transistor.

Almost immediately after this cable shipped, it was discovered that devices using only the Tx/Rx/Gnd connections (no hardware flow control) would not work with the Axim and this cable.  It appears that the cable circuit is expecting voltage on the DTR line to power up the cable.

This posting is preliminary, but I think cracked this problem with no electronics, just jumpering connector pins.  Here is my investigation process;

I intitially confirmed a serial connect session between a Jornada and Axim using vxHPC, settings 4800,8,n,1 using a null modem connection... communication occurs in both directions with no issues.

Using a Magellan GPS (which has only tx/rx/gnd connections) I confirmed that the Jornada received the Magellan's serial NMEA output, but the Axim did not.

On a hunch, I inserted my RJ-11 serial connector schema  between the Magellan and Axim and clear NMEA output from the Magellan appeared on the Axim's terminal screen... problem solved.

The db-9 pin jumpering can be seen in the wiring diagram for the RJ-11 serial adapter diagram below (the db-9 pins 1, 6 and 8 are connected) and you can make your own decision as which connection did the trick.

The trick is to loop one of the the Axim's serial state pins signal to power the GPS "DTR" pin and trick the Axim cable into powering up... since you will need to deal with the null modem requirement for a GPS connection, the needed gender change, null modem and pin loop can be built into a single adapter or you can customize the GPS connector.  Would suggest against jumpering the cable from the Axim as PC connection's flow control would be impacted.

I would, however, suggest considering creating the two headed serial cable using the same information that is posted above for the Jornada serial cable.  I cannot tell you how many times this cable has saved me time and trouble when serial connections to other devices were necessary.


RJ Serial

The serial connection system that I have been using for about 20 years has proven to be a real asset in connecting a wide variety of devices to both the Jornada and the LX. The basis of this system are six conductor RJ-11 "modular" telephone type cords which provide an "automatic" null modem (or not) connection to a wide variety of serial connectors.

In the image below all of the connectors shown use telephone type six pin "RJ" connectors, wired in a way that provides significant flexibility. Most of the connectors below that were used with the LX are now serving with the Jornada.
HP Mimimalist's Travel Kit

The LX serial connector is 10 pin, two rows of 5 pins.

The LX serial connector pins on the LX match "standard" PC serial DB9 connectors...

pins 1-9 will match the db-9's pins 1-9 and pin 10 is protective ground... I _think_ pin one is the upper left when looking into the connector with the LX bottom down.  (shouldn't matter, if you wire it exactly as a DB-9 and it doesn't work one way, invert the connector)

While the LX connector "looks like" the same spacing as a standard ide hard drive connector, it is NOT

...however, it is the same spacing as the small laptop ide connectors, so, if you can obtain a laptop ide connector, it is possible to cut off a ten pin "chunk" and fabricate a working connector.

The second part of the system are DB-9 (or 25) connectors with modular RJ-11 (6 or 8 connector) DB shells. These can be found in most electronic shops, but are generally either wired pin to pin or with a pigtail that goes only to a single pin that you decide in which pin position to plug it into. The following requires a bit of cutting, stripping and soldering.

I wire these as follows. NOTE! since I have found a great deal of descrepancy in how RJ connectors are numbered and colored so the following is a "Back side (wire lead side) view" of an RJ-11 jack.

While the colors accurately represent the traditional wire "pairs" it is extremely common for the sequence to be reversed, which is OK for phone connections, but not for serial connections.

  RJ-11 as viewed from
  the connection lead "Back (wire lead) Side"
  of an "DB-RJ shell" jack
 white   | -- |
 black   | -- +-+
 red     | --   |
 green   | --   |
 yellow  | -- +-+
 blue    | -- |

Then wire the connections to a DB-9 or other serial
connector as follows.

 db-9   RJ-11              DB-25
 -----  --------           -----
 1,6,8  black              5,6,8
 2      red                3
 3      green              2
 4      yellow             20
 5      white and blue     7

The six conductor telephone type cords should have six pin RJ-11 modular connectors attached so that the connections on each end are "flipped" after crimping. In the case of the LX connector, after soldering the wires to it, I crimped a modular "plug" on the other end of the wire to keep size to a minimum.

"Flipping" means if you hold the ends side by side so you can see the wire colors through the clear plastic, the colors in the connectors will connect to the pins on each end in reverse order.

That's all there is to it. I orignally used a single 10 pin LX serial (shown in the picture) connector with a few inches of six conductor telephone cord ending in a 6 pin telephone type RJ-11 modular connector, but after the camera entered my life, I made a similar cord that included a 4" cord and 1/8" audio plug (from a dead stereo headset) in addition to the HP serial connector and modular RJ-11 crimp. This allows me to start a download using Itoh's LXDC software and put the connected units into the belt pouch. Both the camera and computer automatically shut down after the download.

As for the RJ-11 to DB9 adapter shown in the picture, I was able to cut it's size in half by removing the metal shell from the DB9, then cutting the RJ-11 portion of the plastic shell off and gluing the essential pieces back together. A good molding company could probably cut that size in half again.

The "Carry Kit" shown above includes a 6pin modular coupler and a six foot section of six conductor telephone cord. The cord serves both as a serial cord and as a modem telephone connector.

In addition to the DB-9 unit shown, I have an RJ to DB-25, an RJ to Mac Mini Din plus mini DB-9 and DB-25 gender changers that gives me full null modem connection capability at a fraction of the size and weight of most cables.

I have also replaced the standard serial connectors on a variety of serial devices such as the Tripmate, the X-10 CP290 and other serial devices with an RJ-11 modular crimp connector to provide a simple easy small connection to the LX. Not only the LX, but each of the desktop computers I sit at has at least one RJ-11 cable on the desk next to the keyboard for a variety of uses including LX file transfers.

Coupla notes. The beige modular RJ "End to End" connectors must have six pins and be wired so the pins on the same side of the connector are connected to each other. That provides a continuity of the "null modem" wiring if one or more cables are connected in series. I have successfully run serial with these connections in excess of 200' with no problems. It is also easy to customize connectors to directly connect printers and modems with the same modular cables.

In addition, I carry a short 1" section of "unflipped" telephone cable with modular connectors plus an additional"End to End" connector. When this is included in any cable connection, it serves to effectively remove the "nul modem" effect of any cable/connector combination.

However, the above will system will work almost anywhere except for an ActiveSync serial connection which apparently actively uses all of the flow control signals to maximize serial throughput.

Finally, no picking nits about the RJ-"11" description. While I know that there is a different number designation for each "RJ Modular" connector depending on the number of pins and other configuration issues, my experience has shown me that most of the world only responds to "RJ-11"