SimulCharge USB for Phones: Car Music Player

5th Wednesday, 2014  |  Life at LAVA  |  no comments

The LAVA SimulCharge USB charging and USB host mode adapter now exists in a version for Samsung phones; specifically, the Samsung Note 2/3/4 and S2/S3/S4 (see compatibility list for all supported devices). This charging adapter makes it possible for you to attach USB peripherals to your phone in USB Host mode, and to continue to charge/power your phone at the same time.

Here’s a scenario: you might find (as I do) that it’s nice to have the music I’m currently interested in all on one memory stick. I can easily update music on my memory stick and plug it into whichever computer I am using.  With the SimulCharge USB my phone becomes a useful part of that system.

It might also be that your phone has limited memory and no ability to add a micro USB card.

I can now plug my phone’s audio output into the car stereo’s “Aux” input, and use the SimulCharge USB to host my memory stick while still charging my phone. That way I don’t listen to music in the car and arrive with a depleted phone battery.

There is more than one way to skin this cat. In fact, there are three ways of connecting your phone to your car stereo, and four ways to inject USB power into the SimulCharge USB. Here are the pieces:

• car radio with auxiliary input (3.5 mm phono plug) AND a 3.5mm to 3.5mm audio patch cable
• car radio with auxiliary input (3.5 mm phono plug) AND a 3.5mm to Bluetooth adapter
• car radio with built-in Bluetooth

• phone with OTG capability (for the SimulCharge USB, a phone compatible with the SimulCharge USB)

• LAVA SimulCharge USB for Phones (PL-002)

• a USB A to micro USB B cable (your Samsung phone charger’s cable) AND a cigarette lighter-to-USB adapter (Note: these adapters typically supply 1 Amp power at 5 volts, which is less power than would be provided by your phone’s charging adapter)
• your Samsung phone charger with cable AND a cigarette lighter-to-AC inverter
• your Samsung phone charger AND a built-in AC inverter in your car

The whole system. in its variants, is shown below.

car_layoutsSome notes on this diagram:
1) the radio options available depend on the make and model of radio; most these days have at least an AUX input, and many have built-in Bluetooth. Indeed, many also have USB inputs that will take input directly from a USB memory stick.
2) The car powering options depend on what particular power sources a car has. The traditional cigarette lighter is pretty much universal, although some cars have built-in inverters to provide AC power as well. The advantage of power options 3 and 4 is that they use the Samsung USB power adapter, which supplies 5.3V at 2.0A, whereas the typical cigarette lighter to USB adapter (Power Option 1) outputs 5V at 1A. This difference in power output can make a significant difference in charging. The image shows the power connectors of a 2012 Lincoln Town Car, a vehicle which is particularly well equipped with power outlets.

Finally, if you want to take another approach altogether, here’s a hacker’s take on car audio, using the Raspberry Pi SBC: