Database Users

Car charger Modding

I noticed a few complaints on this forum and others about Goggle Navigation being too much of a drain on the handset even with it plugged into a car charger.
My suspicion is that this is down to badly made car chargers, and on a previous occasion using the Testing menu, I noticed that my own charger was being reported by the phone as USB.
So I set about trying to rectify this, using my awesome rolleyes knowledge of how the phone recognises what it's being charged with and an 'I don't care if I kill the charger, it was free' attitude.
I took it apart and tested continuity between the 2 middle (data) pins on the USB plug, there was none, and the problem was identified. I simply flipped the board over and soldered these 2 pins together and reassembled the charger.
Took it out to the car, plugged it in and lo and behold, the Testing menu now reports that it is plugged into an AC source! As my phone is fully charged and I don't have any trips planned right now I don't know how much real world difference there is, but it's looking promising, at least the phone now knows it can draw 1000mA instead of 500mA, and for 5 minutes 'work' it was worth doing.
I didn't bother with a how-to as I figured chances of someone having the same charger as me were slim, but pics aren't a problem:
Here is my universal USB charger with the cover removed:
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and the reverse side with the 2 pins soldered together:
Probably doesn't tell you a huge amount unfortunately, but to be honest that's because it really is a simple procedure with not much to tell.

where did you get your universal charger? I'm wanting to chop one up and hide the nexus dock on the side of my GTI instead of blocking my 6" double din monitor..
Almost like you can do your radar detector..
-Chalrie

It was an Xmas present, part of a universal kit. It's made by Mountech if it helps though.

thanks I'll look it up, hopefully most universal ones are designed the same usb wise then I could dremel my dash and have a easy access usb port for nav.

Fail!
Despite the mod, it's still not enough to charge/sustain the N1 with Google Navigation running (screen on full brightness). Guess it's just not man enough to produce the required 1A.

I have a USB port installed in my car as per the headunit
at full brightness and while using google navigation AND streaming Slacker via bluetooth... I do not have a -% charge
in fact, the N1 stays fully charged at all times... (however if I have less than 100%, it does take a long time for the % to go up... might take 5 minutes for 1% increase)
sooo I'm not sure what the problem is with the car chargers (as I don't use one)

I have a USB headunit and never thought to try and charge from it! D'oh!

[A] - Hardware Hack - Solved the no-charging battery when everything else fails

My daughter's Nexus 7 wouldn't charge.
After trying ALL the tricks found here and elsewhere I bought a new battery for $40.
Replacing the battery gave me the ability to boot the tablet and I discovered that it was not charging anymore : when powered off, the white on black battery sign wouldn't show up and when booted, the small battery icon wouldn't show the lightning sign when plugged in.
I tried all the chargers and usb cables to no avail.
I then tried to power it using the pogo pins and THAT worked. :laugh: I was finally able to charge it but using the pogo pins.
Conclusion : sometimes the internal charging circuits that links the USB power to the battery is dead but another path exists between the pogo pins to the battery.
The best way to solve my problem was then to buy a dock but :
I couldn't find one below $40
My Daughter's cover wouldn't fit into a dock
So I decided to do a small hardware hack to resurect the Nexus 7 : to internally short-circuit the +5V pogo pin to the +5V USB pin.
It took me about 5 mn to do so and it's been working for a week now with no flaw.
Disclaimer :
I do NOT advise you to do this, Do not do this.
If you do, I'm not responsible of any damage you should encounter.
It really is a last chance option, and it only works if you have that (rare!) problem.
You can tell that you have the same problem if the tablet is charging with a dock and not charging with a USB cable.
If this is the case, you'd better buy a charging dock than doing this.
Hardware fix (see disclaimer)
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In the picture above, I just soldered the +5V pogo pin (bottom right when on the screen) to the USB +5V (right one when on the screen) using thin cable.
To do this I first removed the speakers (3 screws). The standard thin wire was preimpregnated with solder paste on both ends and I only briefly (2sec) heated the wire end on the pogo and usb pin to make them catch.
Problem solved.

How to plug a [Joying?] HU to a PC Power Supply?

Hello, I've just received a Joying Head Unit, and would like to 'prepare it' calmly at home.
I would like to plug a computer's power supply to the Head Unit to boot it up, and check it before starting to mess up with the car.
Can anybody point me in some direction as what to plug where? I guess basically I would need to plug the 12V entry and ground, but don't know exactly where...

OK, these are the cables:
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I see a red 'thick' cable that is labeled as 'ACC'. That one I guess goes to the 12V.
There is another orange one that has a cilinder labeled as "JY-VWA V01". I guess that could be an aerial fuse. I would connect it to 12V too
Then I miss a black cable to connect to ground (maybe I can connect the power supply black 0V cable to the metallic frame of the Head Unit) but I think maybe there should be a cable to achieve this.
Another question that I have: the 'thick red cable' labeled as VCC is the male of another thick red cable labelled "Note: if install in high configuration car, please disconnect label area connector" (WTF does it mean?)
I guess both red cables should be connected when I connect the unit in the car to the VW harness, but not sure there as I cannot understand what can that label try to say...
Any ideas?

Ok, finally I figured out.
1st, I unplugged the CANBUS module
2nd, I plugged the red male-female VCC cable
3rd, I took from my computer PSU out a yellow line (+12V) and a black line (GND).
4th, I plugged the PSU's yellow line (+12V) to the RED and YELLOW
It's working now...

thanks for posting this, I could never figure it out. Everyone just says "any 12v power source will work", which is true but, leaves out a bunch of steps

CadillacMike said:
thanks for posting this, I could never figure it out. Everyone just says "any 12v power source will work", which is true but, leaves out a bunch of steps
Click to expand...
Click to collapse
The principal is the same for all head units. You can view this clip that should help you:

N7 + Carplay dongle needs constant ignition start/stop uninterrupted source of power

I have almost conquered my carputer solution. Everything works pretty great as long as the car is running:
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But there is one critical issue occurring during stop and start of the engine. My "wireless carplay dongle" from Carlinkit is very finicky about having a constant source of power and when I get a split second power drop during ignition stop or start, the dongle loses power over the OTG cable. Once this happens, I have to restart the tablet to get the OTG device to be recognized again.
This dongle is connected to the micro USB port of the N7 via an OTG+Charger splitter cable. I need to somehow feed a constant source of power to the dongle via the car. Otherwise, it resets and has to be manually resynced for the tablet to recognize it.
I've tried to use my little Jackery 3200mAh battery pack to serve as backup power to the tablet while the ignition is off, and this does keep the tablet and the dongle powered, but whenever I start the car, their is a split second power interuption and the dongle shuts off and has to then be manually re-synced to the tablet.
I need to figure out if its possible to avoid this power interruption, either with a more sophisticated USB battery pack/charger with more advanced circuitry that doesn't drop power when the ignition is toggled or alternately, a non interuptible power tap from the fusebox or from the battery terminal itself.
Thoughts? Any help much appreciated. I'm almost there!

As a workaround, is there a one-touch or one gesture means of restarting the tablet? Granted, its not too difficult to restart the tablet by pressing the power button and then clicking the "OK" link on the screen to confirm reboot/restart. However, when you are driving, that's way too precise and complicated to do. If there was a gesture or pattern I could swipe on the tablet, or perhaps even a triple click to instantly restart the tablet, that would make this whole power cycle issue much easier to deal with until I can find a solution (assuming one exists)

UIS8141E based head unit, L818_168-Ver_K5 motherboard problem.

Hello,
First of all, thank you for taking your time and reading my post.
Recently I purchased the android head unit for my car. During the installation process, I quickly connected the cables to test the unit before mounting it. The unit turned on and booted without a problem, but the screen was upside down, so in order to mount it, I had to rotate the screen. I disconnected the screen cable and the digitizer cable, rotated the screen and reconnected the cables. After testing the unit again, there was no display! The backlight was randomly flashing and I was even able to hear the radio. So the unit was turned on, I had a problem with display. I made a mistake: I didn't take a photos of screen connectors, so I think I incorrectly connected these cables. After several attempt, I pressed the RST button for a while. I thought I was a software problem and pressing the RST button would RESTART the device. But after pressing the RST button, the unit is dead. It doesn't turn on, anymore., the screen is black, no backlight. When connecting power cable, the LED lamp near the CPU is turned off. I tried to connect it to the PC using a USB cable. When I connected it, nothing happened, no new device was detected on PC. I checked the fuse and it is OK. I also recognized some testing points on the motherboard and these points appear to have correct voltage, 3,3v and 5v.
However, the LED_VCC is 0 and LED+ has 0 voltage.
I haven't flashed any custom firmware. Is there any chance to recover the device? Maybe I need to follow some instructions after pressing the RST button?
I've attached some photos of the device.
The CPU is: UIS8141E,
4GB RAM, 32 GB ROM.
It should have android 12, however I didn't have a chance to properly identify the OS.
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