yashsingh1/xdaforums huggingface dataset:
[Android General] alexderev:
After long hesitation I decided to continue experiments and ordered new device. It is no-DVD version with 7" screen. Now I'm waiting the delivery of the order. While waiting I had some questions rised mostly of a theoretical nature.

1. Which IC can contain the bootloader? Can the bootloader be in flash memory chip with other parts of OS? Maybe there is a chance to get the raw memory dump from working device IC and flash it to dead one by some hardware programming device. Seems theoretical but may it be put in practice?

2. Now the screen of the device has 800x480 resolution. But I find many offers of 1024x600 screens on ebay and aliexpress. I think it not so hard to replace the screen of the device but I'm not sure that firmware and/or MCU will support it correctly without any modification. So the question is how large the modifications can be? Or may it be better to wait when the new devices with higher resolutions will appear and take the firmware from them?
[Android General] Miwer:
I'm pretty sure (not 100% though), that the the MCU (STM8AH ST) chip is responsible for the bootstrapping process, and a great many other low level things. Without that chip, nothing works.

In theory, you've nailed it. A raw code dump from the MCU would provide a lot of useful information about how the device works (booting, firmware upgrading (and encryption/obfuscation), communication between the various hardware components, etc.).

However in practice, that's easier said than done.

You see, most MCU's have a feature called memory protection (this chip is no exception), which prevents any readout of the code programmed into the device. It is essentially a copy protection feature the programmer can (and often do) use to protect his/her work from being stolen and reused by others, who want to profit from the original authors work.

I have not read about any attempt to read out the chip yet, so I'm thinking that they are most likely readout protected, otherwise we would surely have "cracked" the firmware encryption scheme by now. I could be wrong though, maybe there hasn't been any attempt at this yet. It can be quite involved, since it requires desoldering of the chip and use a programmer device to read it (unless there's some accessible ISP pins somewhere on the board).

If you can get a working dump from one of these MCUs, you will become very popular in this thread (challenge, who will take it?) ;)

--- Edit: additional info ---

I should add, that even if the MCU is readout protected, it is still possible to read out the content of the memory banks (that is, if you have the proper equipment) - I don't think these chips are certified for military secrets, so I suspect an invasive attack on the chip would be no trouble at all for an expert. I've seen companies promoting their ability to extract code from protected chips. But it would still require someone to sacrifice a working chip. :eek:

http://www.cl.cam.ac.uk/~sps32/mcu_lock.html
[Android General] sciallo:
I thought about trying, but did not. I have my old board still, but it's bricking was due to interrupded MCU update, so I don't think it would be a good sacrificial chip as I suspect it doesn't have the code we're after installed :rolleyes:

Back in the beginning of this thread you can see links to spec sheets and the chip programmer/reader for this chip. as well as some attempts to figure out the pinout on the board.

From what I can remember, it doesn't seem like the pins on the chip you would connect the programmer to are connected to anything on the board, I'm not sure you would need to desolder the chip from the board to read it or write to it if you can connect directly to the pins (tiny ass soldering though). The programmer is cheap enough, in the order of 20-30 us$... a new board, not so much
[Android General] Miwer:
Despite the failed MCU update, I still believe it would be interesting to dump the code.

When dealing with an MCU with self-updating features, normally the developer choses to divide the flash memory into two sections: the bootloader (aka User Boot Code area or UBC), and the main program (rest of the flash memory). The UBC section will be kept very simple and static throughout the lifetime of the processor and only the main program section will be upgraded through the program running in the bootloader. In this particular chip, the UBC (if defined) is actually write protected, and cannot be updated through the running program, and therefore SHOULD prevent bricking of the chip itself. The key to cracking the firmware encryption is going to be in this UBC area, and this is also where any self-updating code would reside.

So a memory dump could still be interesting, MCU code working or not... :)

Hope it makes sense... ;)
[Android General] chanh55:
I bought another head unit off ebay. It looks like it only has USB in the front and nothing in the back. The one in the back are just cables connected to the board. My question is, if I took the USB cables from my bricked one and put it on the new one with none included, should it work? Do I have to worry about it not having drivers or anything?
[Android General] alexderev:
Agree. Most likely the MCU chip memory has readout protection like in AVR mirocontrollers for example. And it will be almost impossible to to read memory content from chip in such case.

I'm not so skilled in MC hacking, just an amateur :) But in any case I'll try to read the datasheets for this MC and maybe make some testing of MCU chip.
[Android General] rdlemaster:
Possible use of the AN-21 only for the case / amp / etc. ?

I've been reading through this thread and the software thread as well and I've been thinking about purchasing one of these. The problem I have is that the pc part of this unit seems to be somewhat proprietary, thus making it difficult to do some things I'd like to with it.

I'm wondering if anyone has thought about using one of these but replacing the actual controller with a more open single board computer such as the ODROID or the Radxa Rock, etc. ?

Form the pictures I've seen of the internals for the AN-21, it looks like the 6.2" screen would be tough to use with one of these boards and I'm not sure about the other components.

The reason I'm thinking along these lines rather than just building a unit from scratch is that I like the way the CD/DVD, flash card, and volume/other button controls are laid out. To me, if I could use those things plus the power supply, amp, and the cage it would be worth the 250 or so I can get this unit for.

Has anyone else thought about this?

Thanks,

Russ
[Android General] alan.cramer:
Is there anyway to add odb2 to these units without it? Is it a case of changing the Bluetooth inside or attaching a Bluetooth dongle?
[Android General] sciallo:
I think in theory it would be a matter of swapping the bt board. Not sure about the rest of the board and mcu though. The best solution for odb is undoubtedly a usb odb reader, faster and more reliable too...

As far as bt dongles I would love complete by functionality like it was achieved on the ouku. They were able to compile some modules by using kernel sources from a "close enough" device, no real attempts have been made with the an-21...
[Android General] chris.r.r:
Wanted to give you a short update on my external mic hack... Last friday I finally managed to find some time to attach an external mic.

Firstly, I desoldered the cables of the internal mic where it is connected to the board. For the VW version you have to detach the faceplate (only a few screws, take care of the ribbon cable of display and touchscreen). The spot where the internal mic is soldered on the board is in the top left corner of the unit (or right top from the backside ;) )

Afterwards, I soldered a 20cm unshielded cable with a female mono jack on its end onto the board pads. I routed the cable through the inside of the casing and out through one of the holes on the backside of the unit.

In terms of volume there is not a huge improvement, but it seems that the voice is less distorted with the external mic. Maybe this is due to the better quality of the external mic.

Anyway, the improvement is smaller than expected :(

Is there some improvement on the volume issues with the current firmware versions?

Maybe I try a preamp at a later stage...
[Android General] cool_head:
Where can i get a new motherboard for this unit?
[Android General] cool_head:
Nevermind! Already buyed! If somebody need a new board you can buy in aliexpress for 75eur

http://www.aliexpress.com/item/Android-4-1-Motherboard/1623235987.html
[Android General] jitun:
external mic: and the setup is complete

Installed an external mic and the voice quality is awesome. :D

As described earlier in this thread I opened up the head unit desoldered the internal mic from the board behind the front faceplate and soldered a female 3.5mm cable there. I had planned to use a preamp but the external mic worked so well.

I am using "Digital Innovations MM760M Mini PC Microphone" and the audio quality is awesome. The mic does pics up the background car noise to some extent and I have to put the mic below the steering wheel column as it was too sensitive and the audio was getting clipped at the highest amplitude.

I guess in future i will make a preamp using Analog devices SSM2166 chip. so that i can do differential input, noise gating to get rid of car engine noise and use AGC to eliminate clipping. but it all depends on how much free time i have
[Android General] 98ali:
can it fit this device ?

Hardware

Operating System: Android 2.3.*

CPU: FREESCALE I.MX535D Cortex A8 1GHz

Ram: DDR3 512M

iNand Memory: 4G/8G (two variations)

Audio

4x 45w Amplifier outputs

1x Subwoofer output

4x Pre-outs

Built in microphone

Features

External Memory:

Up to 32GB/SD Card

Up to 1TB Usb mass storage drive

Built-in Bluetooth (For hands free phone/audio streaming only)

GPS

iPod

RDS

Steering Wheel Control

WiFi and 3G (with USB dongle NOT HOT SWAPPABLE)

Connection of multiple USB devices through a USB hub, including wireless keyboards, USB memory sticks, and wireless dongles. These types of devices are hot-swappable.

Subwoofer Output

Resistive or Capacitive Touch Screen

Digital TV or Analog TV options

Display Ratio 16:9

Screen Size 6.2 inch (And up depending on car model variants)

Screen Resolution 800 x 480

DVD player Media Type DVD-R/RW, DVD+R/RW, AVI, MPEG4, CD, CD-R/RW, CD+R/RW, VCD, Mp3, WMA, JPEG, Mp4, DVD, WMV, MKV, WAV, JPG, TXT, PDF

Radio Response Bandwidth AM: 522 KHz-1620 KHz;FM: 87.5 MHz-108 MHz

Amplifier Max Output Power 45 Watts x 4

Remote Control

Connectors: 1 x A/V IN, 1 x A/V OUT, 1 x REARCAMERA, 1 x STEERING WHEEL CONTROL, 1 x IPOD, 1 x TV ANTENNA, 1 x POWER, 1 x AUX-IN, 1 x SUBWOOFER, 1 x USB, 1 x GPS ANTENNA
[Android General] 98ali:
help need a screen replacement

hi for all

can any one help me finding a screen replacement for the device ????
[Android General] cool_head:
You have to check if the main board is the same as picture shown in aliexpress..

You can ask the seller in aliexpress..
[Android General] Black6spdZ:
anyone have pics where the back USB port(s) connect to the board? my unit came with one on the back and I'd like to add an additional if the provision is there to solder another pigtail. Thanks

nm, found it
[Android General] cool_head:
Some boards have 3 usb connectors some have only 2 (one for back, another for the unit faceplate). I've got 2 boards and both are different. If you need more usb ports you can add an usb hub. It works perfectly.
[Android General] foggydew88:
I've got an excellent result with the following mic:

http://www.aliexpress.com/item/3-5m...mic-with-3m-length-cable-mini/1811293943.html

Now my input audio is perfect.

Inviato dal mio HTC Butterfly s con Tapatalk 2
[Android General] Miwer:
ARM board and temperature probe + MCU programming header

This post and the following couple of posts with images, inspired me to have a go at opening my AN21-U without damaging the warranty sticker (pretty clever, thanks [MENTION=4736782]kaween[/MENTION]) :)

It was said that the ARM cpu is getting pretty hot, so I decided to put on a probe and test this. After one hour of driving, the temperature settled at between 65-66°C (the temperature was jumping up and down according to acceleration and deceleration, hehe). Ambient temperature in the cabin was around 22°C, but air circulation around the entire head unit is not too good, so the small fan can only help so much...

No wonder kaween decided to put on a heat sink. The temperature is not critical in my case, but it's uncomfortably high for my taste. I'm glad I don't live in a warmer climate. :)

I also traced (and measured) some of the PCB tracks from the MCU to a 6 pin header nearby (only 4 of them used it seems). I believe this is the programming header for the MCU. Referencing a datasheet, I mapped the header pins to the MCU pins in the attached picture. I haven't tried to connect a programming/debugging tool to try and read out the chip (it's almost certainly locked anyway), but it should be possible to communicate with the MCU on this header.

/Miwer

PS: Why can't I have my attached images shown as thumbnails, like other users do? They show as "Attached images", not "attached thumbnails", and there's no preview. Is there a special tag I must use in my post?
[Android General] kaween:
quote :

PS: Why can't I have my attached images shown as thumbnails, like other users do? They show as "Attached images", not "attached thumbnails", and there's no preview. Is there a special tag I must use in my post?

Heh, I wondered about that too.

I'm not surprised about those temps you're seeing. I did a quick'n dirty measurement and after only 2 minutes, my ARM showed 56°C or so, and that with an open case and the unit running basically idle.

Considering the temps may run very high in the summer, certainly when your car has been standing in the sun in some car park or whatever, imagine the situation where you do a little holyday trip with wife and kids, and suddenly your unit can't cope with the temps and your Navi refuses to help you while you're 500km or more away from home.

Not my idea of fun. :)

Thanks for the info by the way ! I'm still waiting for my silent 12V fan, it's a low cost 2€ afair, but with 22db, it should hardly be noticable once mounted. To have a better airflow, It would be far better if the unit would have some holes in the baseplate opposite of the arm, and mount a small fan at that position.

I shudder of the idea that there are AN21 like-designs out there without that small fan or even without a whole for it. CAN NOT be healthy in even the not-so-long run I you ask me.
[Android General] gyaku_setsu:
iPod Connector as 3rd USB?

Has anyone tried to utilize the proprietary iPod connector as a 3rd USB port? Would that even work? I have searched the internet trying to find some sort of adapter for this, but only come up with a cable that goes from iPod female to USB power and an AUX jack. That might be useful for some, but I am super curious if this interface is handed like a USB connection, or if it is simply a proprietary apple protocol that wouldn't work with anything else.
[Android General] Miwer:
Upgrading bluetooth module BC5 to BC6

Hi there,

Just wanted to share my experience in upgrading my BC5 module to a BC6.

I got the BC6 second hand from [MENTION=509153]cool_head[/MENTION] (thanks also for the hint about MCU version) :)

Since the BT module is just soldered on with a single line header, it should be pretty easy to exchange the modules, if you have some soldering skills.

So here's a small step by step on how I did it:

Took apart the radio, and swapped out the modules.

Upgraded the firmware to 2.8.7

Did a model choose, and selected the enclosed MCU for my model (in this case 4.3.10-1-10-210101)

Restarted the radio

Extra Settings --> Config Info (new after upgrade MCU) --> Enable BC6

I also took a couple of pictures of the modules, and some screenshots of the settings.

I hope you find it useful.

/Miwer
[Android General] Miwer:
"diversity" antenna converter

I previously wrote about the crappy adapter, allowing for connection of the dual antenna system I have in my car. Please visit the post I'm quoting, to see just how crappy it was. :)

Since then I've been using the single antenna adapter, which gave me a much better signal, but still with a small amount of dropouts when driving.

So I decided to take it apart and see what's inside, and lo and behold, it actually has two inputs. :good:

I drew up a schematic for anyone interested, and replaced the single connector with the dual connector from the crappy adapter.

The case wasn't glued, so it was easy to prise open with a flathead screwdriver.

The wires on the dual connector was absolutely horrible to solder though... There was some sticky residue on the copper strands (probably leftover from the poor quality insulation). I got one of them soldered fine, but I had to replace the other one, because the solder just wouldn't stick (even after a thorough cleaning).

This is not a proper diversity antenna converter (that would require integration with the tuner chip itself), but I hope it is good enough to eliminate most of the dropouts. It's already installed and I had my first drive with it today. I didn't notice any dropouts, but it wasn't a big problem to begin with, so it's hard to tell if there's any improvement. Time will tell.. :)

/Miwer
[Android General] scott_lai:
I have one AN-21U compatible unit but having 16g emmc rom. But after updating "full format.rar" downloaded from "https://yadi.sk/d/tbaxJYL9cJjKK/Firmware", my internal sdcard storage(/mnt/sdcard) become 5.74g. Is there any way to bring my missing 8g back?

Btw, is there any way to increase /data size?
[Android General] shadowmike:
You need a full format for your device.

The full format you used, formatted it to a 8 gig partition.

sent with HTC ONE M8

An21-U file repo [url =https://passport.yandex.ru/passport?mode=auth&from=cloud&retpath=https%3A%2F%2Fdisk.yandex.ru%2F]Log-In[/url] U: xdaan21u P: u12naadx
[Android General] yucastanharo:
Is there any place or a link to buy a BC6 module? Thanks!
[Android General] doctorman:
I am in the process of buying OEM fit android based head unit ebay/alibaba

Ebay is full of Jouyus units for my car (2008 toyota Highlander)

I found a well priced unit from a aliexpress seller wit the following specs

can someone please tell me if this will be the same hardware you guys are playing with? AN-21? could it be another kind?

would you guys recommend it? I am worried about the summer in car heat in New york and about Bluetooth quality.

System

Processor	Advance MStar MST786 Cortex-A9 dual core

Max.main frequency	"1GHz (Neon), L1 (I/D) cache 32KB/32KB, L2

cache 512KB; 40nm LP low consumption technology"

RAM	DDR3 1GB SAMSUNG

ROM	16GB

Operation system	Android O/S 4.2

GPU	Mali400M

Main MCU	STM32F100

Power IC	AS1015

Audio output	Stereo output of CD tone

Human machine interface	Capacitive touch screen operation

Working voltage*	DC 10V～16V

Working current*	1.2 ～10A

Standby current*	5 mA

Video system*Automatic	NTSC/PAL/SECAM

wallpaper set	Customized

Display Screen

Screen Type	HD TFT touch screen, support multi control

Display mode	16:9

Resolution	Capacitor Touch Screen 1024*600(7", 8",9", 10.1")

1080P Support	RMVB,AVI,MOV,MKV,3GP,MP4

GPS

GPS module	MST2112

Radio

Chip	Sillicon SI4755

FM/ AM Frequency*	FM:87.5MHz～108MHz; AM:522KHz～1620KHz

Tune method*	PLL frequency complex tune

Display method*	TFT Graphical User Interface OSD

Search method*	Automatic/manual

Audio output	Stereo output of CD tone

DVD

DVD RAM	WINBOND 128M

Loader	Shinny with Hitachci 1200XH

Memory	ATM24C02

FLASH SPI	Cfeon 25T16 2M

Servo drive	AM5888

Video output range*	1+10.2Vp-p (75Ω)

Disc spec*Diameter	12cm disc

Compatible disc*	DVD/VCD/CD/MP3/MP4/DIVX/RMVB 1080P

WIFI/ 3G

WIFI	Built in

3G Dongle	Support via USB

DVR: build in

Mirror link

Through	Optional, via USB cable connection, 2-way-control

Bluetooth

A2DP	Yes

Microphone	Inter mic

Received Call	Yes

Dialled Call	Yes

Missed Call	Yes

Download Contacts/phonebook	Yes

Name search	Yes

TV Tuner

Built-in Analog TV	Optional

Built-in Digital TV	Optional

Digital TV type	DVB-T(MPEG2/MPE4);ISDB-T optional
[Android Q&A, Help & Troubleshooting] lovestospooge:
I have an Apex AP-GS918 (Nobis NB09) tablet with rooted stock Jellybean Rom. There is an annoying screenshot button on the bottom bar next to the volume button that I keep pressing accidentally because it is in a bad spot. I wish to disable it or remove it completely. I have searched the forums but all the answers seem to be for Samsung devices. They say to change the quick launch in the settings which I do not have. And they say to remove or disable the system app that controls it, they have different names for the app like screenshotcapture.apk and such, but there is no system app with that or similar name.

If anyone knows a way to be rid of this annoyance, any help would be greatly appreciated.

Thanks in advance.

UPDATE EDIT...

I was unable to find an app to disable, and you were correct that it was part of SystemUI.apk. But I found out how to remove it from the bar. I am unable to post where I found the method because I am not allowed to post outside links yet, So I kind of wrote a tutorial (if you can call it that).

I decompiled my SystemUI.apk using Android Multitool on my PC. I edited \res\layout\system_bar.xml.

The info about the buttons are there. I found the line labeled

@id/screenshot

and changed the following code after it

android:layout_width="@dimen/navigation_menu_key_width"

to

android:layout_width="0.0dip"

which makes the screenshot button 0 pixels wide, meaning not there anymore.

Then I recompiled it, opened the new apk using 7zip and copied the edited xml from it to the original apk to prevent signature failure (after making another backup of it of course), used ADB to push it, permission it, and reboot it. After that I was free of that %$#@ button. I now have to use a third party screenshot app from the play store, but it doesn't have a constant button that leaves me with 50 accidental screenshots a day.

It also works to remove the volume buttons, which are pointless when you have the hardware buttons. Those lines are labeled

@id/sub
@id/add

(on my device anyway). It does NOT work for the 3 dot menu button, but that one isn't so bad to have there.

Take that you cheap Chinese tablet.
[Android Q&A, Help & Troubleshooting] lovestospooge:
Bump
[Android Q&A, Help & Troubleshooting] UltraWelfare:
This feature is included in SystemUI.apk (I think - on some phones) and if you delete it you will have no UI.So don't do it.

Find an app on google play that disables it(I don't know how you will search it :confused: :silly:)
[Android Q&A, Help & Troubleshooting] lovestospooge:
I got it to go away. The method is in the original post. Thanks for the info that got me going in the right direction.