[MTCB Android Head Units Q&A] firefly_hm:
Greetings, gurus and fellow users of android head units,

I recently took the plunge and bought myself one of these head units after much browsing of the forums and trying to read up as much as I can. The exact one is shown here: https://world.taobao.com/item/528347515585.htm?spm=a312a.7700714.0.0.3Y4Xhq#detail

For those who are unable to view the link/understand Chinese, here are some quick specs:

- 10.1 inch touchscreen, 1024x600 resolution

- RK3188

- 1GB ram, 16GB storage

- Android 5.1.1

- MTCC-KLD6-V2.97 Aug 02 2016 10:35:08

Interestingly, this is only unit I've seen so far that still comes with a DVD slot, plus it comes with an external mic, which pretty much solves the issue of the crappy internal mic that many of you have experienced in the past. Also, apart from 2 USB ports that are connected to the back of the unit, there is another USB port in front, just to the right of the sd card slot and below the DVD slot.

All went well with this head unit, but there are some minor issues that I would like to ask for your help or guidance:

- 3G USB dongle is not stable - If I turn on the unit with the dongle attached first, it does not work at all. If I attach it after the unit completes booting, it sometimes will lose 3G connectivity. I have downloaded the mobile network settings app and removed all but 1 APN. Searching on the forums tell me this should pretty much be a power issue. I'm currently looking around to see if I can find a USB hub that accepts 12V DC power so I can connect to the ACC circuit and see if the issue goes away. If anyone has any other suggestions, please feel free to let me know.

- Custom firmware - I decided to try Malaysk's rom from here: http://xdaforums.com/showpost.php?p=69114366&postcount=691 however, it didn't work. After updating the firmware from sd card and wiping the data/cache/etc a couple of times, all I got after rebooting the unit was a black screen and an unresponsive status bar. Booting into recovery shows me the "Block device required" message and a bunch of others that I've forgotten. Fortunately, I was able to restore via USB to a newer version of MTCC-KLD6 firmware posted here: http://xdaforums.com/showpost.php?p=69206883&postcount=165 and everything still works. However, I would still like to try Malaysk's rom, and possibly in the future try 7floor's sound mod.

- Steering wheel control - According to the shop where I went to get my unit installed, my 2007 Subaru Impreza comes with only 1 wire for swc. Using the default Key Study app I was able to map the vol+, vol-, mute, mode, previous ( |< ) and next ( >| ) keys successfully. However, I noticed that sometimes, the keys would not work. Also, the unit sometimes confuses the vol+ and mute signals. Is there anything I can do to make this better?

- Screen dimming - Is there any way to dim the display brightness using the signal from the car's lights? Currently, the soft touch buttons along the left edge of the display will light up automatically when I switch on the headlights, and go dark when I turn the lights off, but the display brightness does not change. End result, I have a screen that is either too bright at night, or too dark during the day.

Many thanks in advance to all who give me suggestions and answers to my questions above. :good: