First off, I'd like to thank you for your input on MHL in this thread; I was able to learn more in 5mins than browsing through the net.
I recently acquired a Galaxy Nexus and a MHL Adapter from Monoprice. Although the combination works like a charm on my TV, with the MHL Adapter plugged in my wall AC Adapter, I still fail to understand how it determines the power source is an AC Adapter vs something else.
Here's my objective and here are a couple things I've attempted:
The objective is to be able to mirror the screen of my GNext onto my car nav monitor (All the car-related parts are there and tested already).
I do have a dual USB Car adapter
(Monoprice) and one of those external battery blocks which can charge at 2Amps as well from monoprice.
Here are also a couple tests performed:
Tweaked USB Cable = Cable with D- and D+ shorted together
1 - AC Wall adapter + MHL Adapter + Standard USB cable = Success (AC Charging)
2 - Power Cube + MHL Adapter + Standard USB cable = Failure (no charge reported)
3 - Car Adapter + MHL Adapter + Standard USB cable = Failure (No charge reported)
4 - Power Cube + Standard USB Cable = Success (USB Charging)
5 - Car Adapter + Standard USB Cable = Success (USB Charging)
6 - Power Cube + Tweaked USB Cable = Success (AC Charging)
7 - Car Adapter + Tweaked USB Cable = Success (AC Charging)
8 - AC Wall adapter + Tweaked USB Cable = Success (AC Charging)
9 - Power Cube + MHL Adapter + Tweaked USB cable = Failure (no charge reported)
10 - Car Adapter + MHL Adapter + Tweaked USB cable = Failure (no charge reported)
At this point, I don't see any additional tests I can perform and I still fail to understand why the MHL Adapter (Which requirement per the doc is:
An audio/video equipment with 5 volts and 500 ma, continue to provide power for portable devices and charging
)wouldn't work with either the Battery pack or the Car charger (which can both deliver up to 2Amps).
Would any of you be able to point me to the right direction to make this work?
Thanks for reading.