[Android Head-Units] edit:
Man, I do envy you a little, to be able to turn down the brightness till the screen gets dark :)

When I turned it down to 5% (without any issue) in 8MayFW from the Car Settings app, the brightness is almost to my liking, in the city, at night, with street lightning filling the cabin it's perfect.... when I drive outside the city, and it's pitch black inside my car, I feel the need to turn it down even more and I use a screen filter app from GPlaystore and I have to enable it manually. At least in the 8MayFW I can define that low point and once set I only joggle with the slider from the notification bar. What I like is that the my headlights are on auto and every time I get in an underground parking or passage (that happens everyday) it turns the brightness down automatically not to get blinded by the pretty powerful light (given that I use Waze daily and it has white background on daytime)

On 12MayFW no matter if I use the notification slider or I enter Settings (joying moded) and use the slider from the Display I can't go as low as in 8MayFW.... There is nothing stopping me, I go the the lowest point on the slider and the screen it's still very bright. There must be a way to tell the unit that the highest point on the slider is 100% and the lowest point is 5%. Now I feel like the highest point on the brightness slider is set at 100% LED power and the lowest is set at 40 or 50% LED power.

As I showed in the pictures they removed the menu from Car Settings that would allow you to define the lowest and highest points of the brightness slider and they defined some SAFE points that work for everyone. Bad move because what is very low for you at 33% it's pretty bright for me. What worked best for me at 5% is unusable for you.

I thought that all the displays are equal but after you told me that yours is very low at 33% i realized why they don't understand me. Because if they test on an unit like you the 12MayFW and turn the brightness down all the way the screen is pretty dark... on the other hand mine is pretty bright.

So I think it all comes down to this :

1. Either they restore the old Car Settings brightness menu, I am fighting for it but the chances are slim to none

or

2. I ask you guys EXTREMELY nicely to help me out on this one... else I will be stuck on 8MayFW... can't go back to android 5... cand't go forward.

I tried to replace the Car Settings app from 12MayFW with the one from 8MayFW, the missing menu did not show up and had some issues with the sound so it did not work.

There is another way, maybe you guys have an idea, when the headlights turn on the unit turnes down the brightness and maybe I could run automatically an screen filter app. It's not an elegant solution but What can I do... I need to compromise.

---------- Post added at 05:23 PM ---------- Previous post was at 05:18 PM ----------

Yes, correct! Now if you can find where and maybe discover how to define how low can it go it will make my day !

Pleaseee help a noobie ! :)

---------- Post added at 05:25 PM ---------- Previous post was at 05:23 PM ----------

I am just composing the tutorial. I do not take credit for any mod that's been presented here.

All thanks go to [MENTION=2550900]surfer63[/MENTION] and [MENTION=503463]AssassinsLament[/MENTION]

In oder to be able to do anything on the unit via ADB you NEED to enable ABD over Wi-Fi so download AoW_v1.0.apk from here https://xdaforums.com/showpost.php?p=71616884&postcount=273 , copy the apk to a stick run it in the unit and let it do it's job. (you can uninstall it at the end)

Part one - Root

1. Go to https://github.com/hvdwolf/Joying-RootAssistant

2. go to the green button "Clone or download" and choose Download ZIP, download the file

3. create folder c:\rootjoy and unpack the zip there

4. connect to a router (home or phone router), and check what IP your headunit has (something like 192.168.1.34)

4. open an command prompt with admin rights

5. type the following without the quotes

- "cd c:\rootjoy"

- "cd SuperSU_for_Joying_Intel"

- at this point restart the unit, once it has booted enter next line (don't let the HU IDLE too long once it has booted because you will get disconnect errors)

- copy_install.bat IP (example copy_install.bat 192.168.1.34)

- if there are no errors, reboot (I followed the steps above and never failed)

6. you are now rooted

Part two - Viper

01. go to this post https://xdaforums.com/showpost.php?p=72064749&postcount=41, click the Thanks button :) and download viper.zip

02. For the me last version of the Viper4Android works ok but the included EQ is broken for me so I used an older version of Viper4Android where the EQ section actually works and you can clearly hear the difference. If you want to use my version go to to step 12 if you want to install the [MENTION=503463]AssassinsLament[/MENTION] version go to step 03

03. unpack the viper.zip to C:\viper

04. open an cmd prompt with admin rights

05. "cd c:\viper"

06. restart the HU, just to be safe, after the reboot enter the next line in cmd prompt

07. enter "viper.bat IP" (example : viper.bat 192.168.1.34)

08. after it finished reboot the HU

09. after reboot ran the app, say yes when it wants to install the driver, wait, it takes a few minutes, if android wants to end the task press wait, be patient, when it's done reboot again.

10. ran the app again, from the left menu select settings, and lock on the heatset profile

11. select heatset profile and have fun tweaking the sound.

12. unpack the viper.zip to C:\viper

13. go to https://xdaforums.com/showthread.php?t=2191223 scroll down to v2.3.4.0 (Android 2.3~5.0)

and download the mediafire link next to it (http://www.mediafire.com/download/cnqqdme51qy9ft4/ViPER4Android_FX_v2340.zip)

14. inside the ViPER4Android_FX_v2340.zip there are 2 files, unpack the ViPER4Android_FX_A4.x.apk to the "c:\viper\viper" folder

15. rename it from ViPER4Android_FX_A4.x.apk to ViPER4Android_FX_v2505_A4.x-A7.x.apk and overwrite the original ViPER4Android_FX_v2505_A4.x-A7.x.apk

16. now you can follow the steps from 05 to 10 pretty much.

Good Luck !