How to build a service cable?
A standard USB Mini B normally only has 4 wires connected (+5V, 0V/Gnd, and 2 x Data Wires). The Nuvi has a 5th Pin (Pin 5 or Pin 'X') which it uses to sense what type of Cable is connected, and controls the charging current.
Inside the Nuvi there will be a resistor connected to the +5V rail and the other end connected to the ID Sensor and Pin 5 (or pin 'X' as it otherwise referred to as).
External to the Nuvi this wire (white) will connect to a Resistor of about 18K ohm in value, and the other end of the resistor to Gnd/Ov.
These 2 resistance values (1 internal, the other external, via the cable), for a 'potential divider' such that changing the resitance of the externalk Resistor, changes the voltage to the ID Sensor pin inside the Garmin Nuvi.
As stated the Garmin Nuvi USB Mini B socket has a Cable ID circuit n Pin 5 (or Pin 'X').
There will no doubt be an internal resistor from the +5V rail to that ID Pin on the Min B USB, and external Resistor (18k Ohm) to Ground (Ov) completes the poential divider and the Voltage on that Cable ID Detect
I learned of this website from a Arvin on RoadGui9de.ph:-
[Only registered and activated users can see links. ] as has been quated here.
Here is my reply to that pinouts.ru website:-
[Only registered and activated users can see links. ]
Because I was using a Garmin Nuvi 255 in a wether resistant handlebar mount case, on my motorcycle, powered from a 12V Power outlet (marine version CIGAR LIGHTER SOCKET with waterproof cap), I did not want to use a standard USB A to USB- Mini B, as this causes it to go into Data Mode, then after 20 seconds it will finally go into GPS Navigation mode.
Sure the Garmin 12V PSU worked OK (but it sticks out rather far, and was prone to vibrating loose and power lost to Nuvi and I would have to push it back down to re-seat it, before the 15 sec count down to Power-Off.
I have since found I can tip the 12V Socket into a more vertical position, so less of a problem.
Regardless. running the Garmin Nuvi off a Dual USB Charger and a custom Cable with 90 Degree USB Min B (having 5P, with 18K resistor off that Pin5 (or Pin 'X'), gets it detected as a PSU Cable, is a cheaper alternative to buying a genuine Garmin 12V Charger (US$25 typically)
Some USB Mini B 5 have a 200K Ohm resistor to ground already fitted. I soldered a 20K Ohm in parallel to get a Garmin Nuvi accptable value to detect as Power Cable.
CDR King have low cost USB 12V Chargers:-
Seems CDR King have a new (cheaper) white version of that SBC-10 2000mAh Battery /Solar Charger
[Only registered and activated users can see links. ]
2000mAh Solar Charger
Php 480.00 (Php100 less than the SBC-10)
New Arrival
Can be charged on the Sun Or PC/Laptop
Polished case and LED power meter
Suitable for mobile phones, iPhone, iPad, Camera, MP3/MP4, PDZ, NDS, PSP and other gadgets
LED torchlight and charging indicator
Specifications:
Solar panel: 0.55W
Built-in Li-on rechargeable battery (3.7V/2000mAh)
Light distance: 3 meters
Charging times:
Sunlight: 9 ~10hrs
PC/Laptop: 3 ~4hrs
Mobile phone: 1 ~2hrs
Size: 100mm x 60mm x 15mm
3pcs. mobile connectors
Package Contents:
1 x Solar Charge (2000mAh)
3 x Mobile connectors
1 x Mobile connector cable
1 x Manual
Can be charged on the Sun Or PC/Laptop
Polished case and LED power meter
Suitable for mobile phones, iPhone, iPad, Camera, MP3/MP4, PDZ, NDS, PSP and other gadgets
LED torchlight and charging indicator
Specifications:
Solar panel: 0.55W
Built-in Li-on rechargeable battery (3.7V/2000mAh)
Light distance: 3 meters
Charging times:
Sunlight: 9 ~10hrs
PC/Laptop: 3 ~4hrs
Mobile phone: 1 ~2hrs
Size: 100mm x 60mm x 15mm
3pcs. mobile connectors
Package Contents:
1 x Solar Charge (2000mAh)
3 x Mobile connectors
1 x Mobile connector cable
1 x Manual
It seems to have all the features of the SBC-10 (unless I am missing something?), but is white color and Php100 less!
It still comes with the multi-Tip Connectors also
It is fairly easy to add a 20k Ohm Resistor in parallel with the 200K Ohm one fitted inside the USB Mini B 'Tip'.
I also cut the plastic case at 45 Degree and inverted one half amd using superglu to join them into 90 Degree Connector
(Filling with Epoxy resin/car body filler to make it stronger if required, once confirmed working).
The only problem is the DC Plug Lead of the Multi-Tip is rather short!
Most USB - DC Power cables are to a DC Plug not socket!
So how about this, as a possible 'fix' to that problem - solder a USB cable of the required length, in place of the solders DC Power 'protrusion'!
For those not so good at DIY and soldering, and want to buy something costing less than a genuine Garmin 12V PSU check this out on eBAY:-
For those with motorcycles, perhaps ands not having a 12V Power Outlet (Cigar Lighter Socket) there is this alternative to genuine Garmin wired supply:-
Pin 4 is X not 5.
Pin 1 = +5V ( 5 volts DC )
Pin 2 = data
pin 3 = data
pin 4 = GND ( empty not connected )
pin 5 = GND ( ground )
Look here:
[Only registered and activated users can see links. ]
Above link seem dead now as domain no longer exists, so try the Wayback Machine: [Only registered and activated users can see links. ]
To make a simple usb charging cable just do this. (No Resistor Needed)
(You can use your nuvi while charging.)
After this mod your cable cannot be used for usb access ever again so make sure it's a spare cable.
Tut:
Take a spare nuvi usb cable.
Somewhere in the middle of the cable carefully cut open the insulation using a sharp Stanley knife or razor blade (Be Careful not to cut open your fingers.)
Cut the 2 data lines (2 colored wires, usually white and green ) Do not cut the RED or Black wires.(Power)
Now Insulate the cut wires on both sides using some shrink tube.
Tape up the cable neatly.
On Nuvi 1xxx the Nuvi will boot into Mass Storage mode for a short while and then boot again to where to screen.
On 3490 the Nuvi will work normally.
The difference between stupidity and genius is that genius has its limits.
Albert Einstein.
Will nuvi go in data mode with this cable?
Does anyone know if it works with an Oregon? I would like to make a long USB cable which I could connect it to an USB-Car-Charger
I cut open a Garmin TA10 power cord. This cigarette lighter cord will charge and power the Garmin in navigation mode. This cord is not a traffic reciever or a traffic antenna but is a traffic activator that has the ability to turn on the traffic receiver in Garmin models that have a built in traffic receiver. I own Garmin Drivesmart models 50 LMTHD and 51LMTHD and can only speak to those specific models.
1. Removing the Cigarette lighter end of the TA10 power cord and connecting a USB type A plug in its place works perfectly (including traffic receiver activation) with all USB charging sources I tried.
2. Cutting open the Garmin USB Mini B plug I discovered a small circuit board with a single surface mount resistor marked "24C" (17.4K) that connects ID pin 4 to the shell of the connector (not to GND). The VCC and GND pins of the Mini B plug are isolated from the shell and all other pins. Data Pins 2 and 3 are connected together on this small board. There are no Data wires going to the USB A connector.
3. I cut a standard USB A cable to about 9 inches and soldered the Red and Black leads to VCC and GND of the Garmin Mini B plug respectively. Again this works perfectly for charging, traffic and navigation.
4. Why a 9" cord? I Modified an old rechargeable battery pack by adding 4 stick-on silicone rubber feet and several coats of clear lacquer on the solar panel so the Garmin suction mount would hold. I now have a portable GPS with active traffic that sits firmly on the dashboard and navigates for over 8 hours.
Spoiler: image
Last edited by timsley; 12th June 2023 at 10:25 PM.
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