In car USB

[Clive]

Hello,

Just looking for some opinions on this.

A few months ago I installed in my Yaris a combined radio/Cd/mp3 player to replace the venerable radio cassette supplied in my 10 year old car. And very pleased I am with it.

I have splashed out on a Galaxy Ace phone (think Galaxy S2 for cheap skates) and happy again. Now I wanted to be able to use the phone for Sat Naving and charge at same time while having mp3s played via a USB connection to the radio (all the technology here). I have two different cigarette lighter to USB adapters =96 one rated at 2.1 Amp. Neither can deliver enough voltage / current (?) to the Galaxy Ace phone to charge it while in use =96 and on a long trip the combination of Sat Nav and phone display pretty much drains the battery of the phone in two hours. However, surprisingly(?), the USB socket from the radio delivers a high enough voltage/current(?) to charge the phone via its micro-USB socket. Good, except I then can't plug a different mass storage/mp3 device into the radio for playing music. I can use the phone simultaneously as a USB mass storage device providing mp3 to the radio and a Sat Nav, which I think is amazing (I am always amazed by technology). However, I am limited to 8GB storage on the phone because of the memory chip on the phone. Really want to use a little hard drive to store all the music, play that through the radio while using the cigarette lighter to simply keep the phone charged. I suppose this isn't possible, or at least with the devices I have. I can't have two devices (phone and hard drive) plugged into the USB outlet from the radio at the same time as that will then confuse it as to which device is actually the storage device. Any other suggestions on things I can try?

[airsmoothed]

Personally I'd stick a microSD card in the phone if 8GB is not enough, and use it as mass storage via the radio's USB - assuming thge radio could recognise both internal and external phone memory as mass storage.

[John Rumm]

Can you change the usb mode of the phone to MTP device or similar rather than mass storage, then plug a hub into the radio, and a hard drive + the phone into the hub. Since there will only then be one mass storage device it should be ok.

Alternatively, have you actually tried the radio with two mass storage devices - it may well let you select files from either.

Finally, have you thought about sticking a larger memory card in the phone?

[Theo Markettos]

If you hub it, it'll break fast charge for the phone.

Here's an idea. Buy a USB extension cable (USB A male to female). At the female end, carefully snip open the insulation and foil, and attach 2 wires to the red and black (power) wires. Take these off to a micro USB connector (probably butcher another cable). Of the micro USB cable, join together the green and white (signal) wires.

The hard drive should plug into the USB socket, and the phone into the micro USB plug. The phone should be fast-charged, and the music will come off the hard drive.

BTW, you may wish to experiment with different resistor values on the phone data port, as you can make it do other things like switch into car dock mode (at least on the Galaxy S you can):