Just a little update from my end. I also used an Axxess swc, only mine was the universal add on one since i didn't have swc to begin with. It works okay, and gets me around but its not great. Reprogramming the buttons is an utter joke and resulted in just leaving them how they are in the default setting. I still can't access the app with my tablet but I can atleast cycle through the audio sources/change songs/volume etc. I'm still not %100 happy with it, but it is atleast functional.
Bit of a thread revival, but I was going to do a very similar install to the OP in my MK1 Audi TT.
The only problem I have is that here in the UK, none of the available Sony App Remote HUs have DAB - I could stream my favourite radio station by tethering to my phone, but the coverage isn't always great.
So frustrating that everything is ALMOST there. I may have to drop SONY an email, but won't hold my breath.
Hey dlbogdan - come back! Now you have enough posts. Did you finally build your "button Press" electronic contraption?
treetop you can read about dlbogdan's adventures in this post http://www.mp3car.com/show-off-your-...custom-hu.html SNO
Assuming that appmode could be activated via the Sony remote, it seems like an Arduino board could be used to clone the Sony remote. Once the Arduino board has the instructions to activate appmode, theoretically, you wouldn't ever have to touch the head unit again.
Again, if any of this stuff that I'm writing is stuff that you guys already know, I apologize. Go to your tablet's Bluetooth settings and find something like "Sony Automotive" in the list of available devices. Connect and pair the Bluetooth audio from the tablet to the HU. You should be able to do this without touching the HU assuming you have connected and paired to the HU via Bluetooth in the past. When you hold down the menu (sound) button on the remote, does it show "SET SOUND" on the display of the HU? If you keep hitting the down arrow button on the remote after holding down and then releasing the menu (sound) button, it should go through these options:
SET APP REM
Once it shows "SET APP REM", you press Enter on the remote, and the AppRemote app should connect to the HU from the tablet. I can confirm this works with the p3100 and the Nexus 7 2013 (both of which I have, but I can't speak to other hardware). Not only does this work using the remote, but I was able to record the remote codes from the Sony remote, and put together an Arduino that replicates this sequence. So now, when the car starts, power is supplied to the Arduino which is programmed to send the connect code to the HU and we never have to touch the HU to connect AppRemote. The HU can stay tucked behind the tablet. Let me know if this doesn't work for you, and I'll do the video demonstration. Also, I'm happy to post the Sony remote codes\sketch for any Arduino folks out there that want to build their own.