[MTCD Android Head Units General] RogerClark:
I've almost finished installing into my Subaru Forester (its installed but I have a few problems to resolve)

I found that I could buy an official Subaru "Gauge pack housing" (part number H0010SA950ML)

Which puts the unit in a much better position for it to be used for navigation.

The original location, of the radio (see photo) is OK for a radio / music player, but not good for navigation, as is far to far from the normal line of sight.

Currently I've left the old CD / Radio unit in its original location, until I can find a better alternative, ideally some sort of storage would be good, but it needs to look good.

For anyone else attempting to do the same sort of installation...

I found that the plastic clips on the housing, made it virtually impossible to remove the housing, once its clipped in place.

I tried clipping it in place before I had the head unit installed, and the only way I could remove it, was to use a Dremmel to cut away part of the clip.

Note, I didn't cut the clips off, I just ground away part of the side of the front 2 clips and I was then able to lever it out, and then use a sander to remove part of the other 2 large clips.

The housing still fits very tightly even without the sides of the clips sanded off, and does not come loose even when driving over substantial bumps in the road.

I initially thought I'd need to cut away the opening at the front of the housing, as its about 5mm smaller (width and height) than the Xtrons unit. But in the end I found it better to position the Xtrons behind the lip at the front of the housing, and its still possible to press the buttons on the left.

Note, As I'm in Australia, the car is right hand drive, and those buttons are on the left. For US and EU drivers, the buttons would probably be a bit difficult to access from the drivers seat, but as they are hardly ever used in normal operation, I don't think its a big problem.

I had to drill my own holes through the mounting brackets supplied with the housing, but that's easy. I offered it up. drew lines on the side of the xtrons, around the edge of the brackets. Took the unit and brackets out again. Opened the top of the Xtrons (Yes this voids warranty).

Held each bracket in the position it would be in the car.

Used a pen to mark from the inside of the Xtrons, into the bracket, for all matching holes.

Removed the bracket, choose 2 holes on each side and drilled them into the brackets.

Then finally screwed the brackets to the Xtrons, using a nut on the inside, rather than the built in (tapped) threads. (as those threads did not line up well with the brackets)

The steering wheel controls work fine. I found that 2 of the 4 wires on the secondary plug going to the existing radio, had a resistance of 4.7k between them, and pressing the buttons changed the resistance.

One of the wires always showed around 3 ohms to one of those two wires, but I don't know what that does.

The other wire didn't seem to be connected to anything, but potentially gets a signal under some circumstances.

Edit.

I'm using Nova Launcher. Works fine. I just need to sort out apps with larger widgets.

I tried the FCC launcher but I can't seem to get it to work, as it keeps asking for permissions to create widgets, and there does not seem to be an option to allow this

I also tried CarWebGuru launcher, and it looks nice, but the volume control buttons didn't seem to work.

Using Here WeGo for Navigation as Sygic does not seem to allow switching between it and other apps e.g. the radio, without starting the route all over again.

I presume I must be doing something wrong with Sygic, perhaps only the paid versions have features like allowing the app to continue to run in the background.

I had to install a separate app to access the developer settings as they have been removed (hidden) in Xtrons custom ROM.

I've enabled root access via ADB, but have not needed to actually use that level of access, as I don't need to root the device at the moment.

I'm using a 64Gb SD card for my music / audio book library, and that seems to work fine.

Audio output volume seems OK, but I think my car may have a power amplifier hidden somewhere.

Remaining problems

1. The radio reception is terrible.

However I'm pretty sure that's because I should have connected the wire from the Xtrons unit labelled "Auto Ant" to one of the wires on the old plug to the radio.

As I now understand that the "Auto Ant" wire, is actually used to power an antenna pre-amp (probably situated near the antenna, which is in the glass of the hatchback window).

I bought an adaptor cable from Subary <-> ISO, but it looks like the Xtrons unit does not connect the Power antenna wire to the ISO socket.

So I'll need to wire that myself.

Update.

I've now fixed the problem with the radio. (and corrected the names of the wires I wrote in the text above).

The problem is that the Xtrons does not have an output for antenna power at all.

There is a wire from the ISO socket supplied with the Xtrons, but bit doesn't connect to anything.

Ideally the Xtrons needs to be able to supply 12V when the radio app is running, but it does not have that feature.

I measured the current taken by my antenna amplifier and its less than 50mA, so I decided to just connect the Accessory power (after the fuse) to the Auto Ant wire.

This means the antenna amplifier is on, as soon as the key is turned onto the accessory position, regardless of whether you turn the Xtrons off or the Radio app is running.

But I think this is the best solution that can be easily achieved.

2. As posted on another thread.

I can't work out how to setup the list of apps that the Mode button on the steering wheel, cycles through.

Its not that I can't assign a function to the button, its just that I don't know how to assign apps to the "Mode" list. :(

3. The Here WeGo navigation app has audio problems with its navigation voice prompts.

I've tied changing the various audio / mix settings for navigation in the Settings (not the app) but it doesn't seem to make any difference.

The audio still seems to fade out and get crackly half way through each prompt.

I presume this is a compatibility problems between the way the Xtrons ROM handles the navigation audio fading, but I don't have any ideas on how to fix it

4. Cooling...

The unit is likely to get a lot of heat, as its right on the top of the dashboard.

Fitting a fan inside will not be a good solution in my case, as the air it would draw in from above the unit will be very hot.

So, my current plan is to remove the back panel, and drill a large hole in it somewhere (probably 1 inch in diameter), and then use a flexible conduit to feed air in from much lower down in the car.

I don't think normal fans are very good at sucking or blowing much pressure, so I may need to get a special fan for this.

Other thoughts

I thought potentially I may be able to use a combination of keys from the steering wheel control, at the same time, because in theory if each button just has a resistance in series with it (all in parallel with a 4.7k resistor).

The resistances (in Ohms) on my Subaru seem to be

Mode 336

Up 605

Down 1143

Volume + 90

Volume - 144

Mute 23.5

i.e in theory Mode and Volume up at the same time should be 70 ohms

and Mode and Volume down at the same time should be 100 ohms

But either it can't detect the difference between 90 and 100 ohms, or the sampling rate is so fast, that the small delay between pressing the 2 buttons down, is seen as only one of the buttons being pushed.

I suspect its a sampling speed issue.

Shame really, as Long press on Mode, followed by some other buttons being pressed could be useful e.g. Step forward or backward though the mode list and then just use the Mode button on its own as the Home button