[Android Software Development] spocky12:
FAQ and more resources related to these devices

Differences between projector devices

Wemax One / Chinese Xiaomi Mi Laser:

They are (almost ?) the same.

Software-wise :

They are exactly the same (exaclty same codename, firmware, etc...)

Hardware-wise :

Wemax is black, Xiaomi Mi is white

Wemax is described to be 7000 lumens (1688 ansi lumens), Xiaomi mi 5000 lumens (1600 ansi lumens) (not sure if hardware is different or it's only a software parameter that changes its laser power)

Chinese Xiaomi Mi Laser/ International Xiaomi Mi Laser:

Software-wise :

Chinese one comes with android 6.0.1 and MiUI Tv (a Xiaomi UI dedicated to chinese users), International one comes with android 8.1 (more details below)

Hardware-wise :

Chinese one is equipped with DDR3 ram, International version DDR4

Chinese one has Amlogic T968 with onboard Mali T830 gpu, International one has Amlogic T962 with onboard Mali 450 gpu (somewhat less powerful, not sure it has any real world impact)

Also note than more often than not, International version will probably come with a warranty. It might be important, as few people complaining about dead white pixels seem to have a hard time getting their chinese projector repaired.

Pros/Cons of 8.1 international device / firmware (as of 10/10/2018)

This might help people choose between 02 international version and 01/wemax devices. Most of the information below come from this test. This is however subject to change as I believe Xiaomi will probably enhance their drivers in the coming monthes.

Pros

Complete software translations (no more chinese ressources)

Better user interface

Google Play Store availability

Better support of media apps that hardly work on 6.01 (Netflix, Prime Video...)

Better default colorimetry (but less configurable)

Less input lag (75,6 ms vs 126,6 ms) fixed on 1218+ firmwares

Cons

No 3d support

Less options related to display settings (missing RGB levels)

Worse image quality as noise reduction and sharpness seem to be less effective than on the 01 version

Judder and image tearing during media playback

Can devices international firmware be flashed on chinese models

No :

- devices hardware is not exactly the same

- partition layout is different (android 8.x requires a vendor partition)

- we don't have access to any international firmware

Supported video modes

EDID data here for "rainman" (1080p version) : View attachment 4841507

EDID data here for "batman" (2160p version) : View attachment 4841505

EDID data here for "jerry" (2160p version) : View attachment 5073709

EDID data extracted with HDMI 2.0 enabled from /sys/devices/hdmirx.28/hdmirx/hdmirx0/edid and analyzed with Advantiv EDID Editor 1.01.0268

Is my 4K device really displaying in 2160p ? Why does YouTube refuse to stream 4k ?

- Yes.

- Blame it on Google. Or AmLogic.

More details here.

Note : more recent devices such as Fengmi Cinema 4k pro (codename Jerry) based on Amlogic T972 soc don't have this limitation (they support VP9 hardware accelerated decoding)(but seem to lack 3D support)

ALR Screens

Interesting post from @servo386 regarding Ambient Light Rejection screens dedicated to UST devices.

Rainbow effect

I see many questions regarding rainbow effect (due to the DLP technology used). What I can say is that I never saw anybody complaining about it on the Mi laser projectors. A previous projector I owned (an Optoma) was also using DLP technology and I could see this rainbow effect from time to time. In the case of rainman/batman, I've never been able to see it.

Input lag

The Mi laser projectors have relatively high input lag (150/175 ms). Firmware updates sometimes help. As of september 2019, the lowest input lag can be obtained on "Monitor" or "Game" mode (approximately 100ms on batman, 75ms on rainman). If your device is rooted and you're using the ProjecTivy Tools, you can also use the "User" mode, and long press the "back" button to get down to the same input lag as "Monitor" mode, with the benefits of keeping your calibration settings.

Dead/black/white pixels

One owner of the chinese version here (french) who had a dead pixel managed to fix it by increasing RGB custom settings above 1500 for some time (don't know how long). When reverting to previous values, the white pixel had disappeared. Didn't work out for another user, but it might be worth a try.

This might change in the future (in this case, please keep me informed), but trying to manually repair by changing the chip is a dead end. It's not the usual Texas Instrument DLP4710FQL, but the DLP4711FQL (source), which is not compatible(source) and can't be bought online.

Display issues with MJJGTYDS01FM (Xiaomi branded 4k model)

Many display issues can affect this device : taking time (minutes) to start displaying something, displaying only half image or white lines/bands... Most issues appear when the device is cold and get fixed when it has heat up.

Seems like a hardware design issue that can be fixed by removing a few screws. More information here. After this, like your projector, you won't be screwed anymore :D

More details can be found here as well.

HDMI input ports don't work anymore in International devices after upgrade

Install the tools, launch engineering menu and select "HDCP key reset" (thanks @xthing)

Cross platform Remote Control

I also developped a simple web based remote control for MiUI TV (Xiaomi with chinese interface) based android devices (such as projectors, boxes, TVs).

No need to install anything special on your controlled device, this website/webapp communicates with the MiUI TV internal web server to send events to your device.

It should be compatible with anything running a web browser (provided it's quite up to date): Android, iPhone/iPad, PC/Mac computers...

Just head to http://mireco.hopto.org, configure your device local IP address and you're good to go.

More details on GitHub.

Other Tools

MiiInfo from 4PDA user Loly, shows various details concerning your projector.

Firmware updates after rooting and/or installing Google Apps

Firmware updates won't install if files on your system or kernel partition are modified. Using the ProjecTivy Tools and installing the Google apps won't modify existing system files, but rooting with magisk will modify the kernel. So before any update, you have to restore your kernel (aka "boot") partition using TWRP, and then reapply Magisk once update is done.

Google Apps Issues / not yet working

Amazon Prime video : it's been reported that Amazon purposefully blocks the app on projectors. The app loads, but refuses to stream videos. Some previous versions (requiring mouse for some features) work fine though. You can install the most recent compatible one using the ProjecTivy Tools.

Netflix : No recent Tv version seems to work. Some previous versions (requiring mouse for some features) work fine though. You can install the most recent compatible one using the ProjecTivy Tools. Anyway, due to missing full widevine support, full hd / 4k will probably never work.

Chromecast framework (Google Cast Server, aka AndroidMediaShell) isn't supported (devices need to be approved by Google to be supported)

Recovery

To go into recovery, turn off your projector, unplug it, hold down OK and BACK buttons simultaneously (OK and HOME for anglee) on your remote and plug back your projector while still holding them down.

Warning : don't "hot-unplug" it, turn it off before, or it won't work.

If you're looking for TWRP, have a look a few points below :D

Unroot

Start the Magisk Manager app and select uninstall

OR

Boot Twrp and reflash the Boot (kernel) backup you made just before installing Magisk

Factory Reset

Reflash the full stock firmware available below in this post. This doesn't require any intervention on your part so it should work even if you can't see the display

OR

Boot the stock recovery and select the "reset device" (not sure of the exact terms) option

Root

Note : both methods below work for rainman as well as batman (4k) devices.

Easy Method:

This method doesn't require any special hardware, only the TWRP I made (3.2.2.0, based on stock recovery files), along with another config file.

Thanks to @cr4zyw3ld3r who made a video tutorial based on the following instructions.

For french people, here you can find a tutorial made by Pierre. Thanks to him.

Extract this file View attachment 4800989 (for "batman" 4k), this file View attachment 4782569 (for "zodiac"), or this file View attachment 4703214 (for "rainman" 1080p and most other devices such as conan) at the root of your (FAT32 formatted) USB drive, where you also place the latest magisk version (magisk 20+ version support has been added on tools v3.5+), and plug it into your projector (I used the right USB port)

I also built (but not tested) a twrp for Vava projectors here : View attachment 4985707 (please report if it works).

Download ADB for your computer (check here)

Start command line (terminal)

Enable USB debugging in Android settings / developer options (you can access them from the projectivy tools)

Type "adb connect IP_OF_YOUR_DEVICE:5555" to connect through the network

Type "adb reboot update" (This will restart your device and make it boot the TWRP on the USB drive.)

Once in TWRP a mouse will be required. Make backups if you wish (at least "boot" partition that you'll need to restore before applying any OTA update), and then mount SYSTEM, and install magisk in order to root the device (it will be in "/udisk" and will be called Magisk-......zip)

Note : to thank the donors, I also developed an application that installs on your Android smartphone, which automates steps 1 to 6. There is no need for computer or custom command lines in this case. Once the app is connected to your projector, you're only one button click away from TWRP.

Note : if it still boots to stock recovery and not twrp, make sure you extracted the zip and not only copied it to your usb drive. If it's extracted correctly but still doesn't work, try another usb drive, a few people reported that this fixed their issue (some users had to try 3 or 4 usb devices before finding one the works).

Old Method:

With the correct hardware, you can root your device, following this tutorial from @servo386

To simplifiy the rooting process described in the link above :

Extract this file View attachment 4799614 at the root of your USB drive, where you also place the latest magisk version (as of now 19.3), and plug it into your projector

Follow the steps described in the tutorial, up to the point where you have a root console access in recovery

Then, according you've plugged your USB drive before starting your device, just type ". /udisk/twrp.sh" in the root console. This will copy the necessary files and automatically run twrp, reducing the number of steps (and potential mistakes) to root your device.

Once in TWRP, make backups if you wish, and then mount SYSTEM, and install magisk in order to root the device (it will be in "/udisk" and will be called Magisk-.....zip)

Roms / Dumps

Due to issues on the new XDA 2021 website (preventing edition of long posts containing many links), full firmwares and OTA have been (temporarily ?) moved to post #4.

You'll have to scroll down by yourself, I can't even add a link to it 🤔