yashsingh1/xdaforums huggingface dataset:
[Android General] sciallo:
Now, just to compare... Here is pics from this board (no longer unfortunately) for sale:

The replacement board doesn't have a TV tuner, other than that, one thing to notice is that a few of the connector pads that are unpopulated on mine, have a connector on there, I guess it's as generic as possible to fit any possible unit.

I believe the one right next to the BT board to be an aux in judging by these pads probably for units that have a front aux in...

I wonder if it would be the same aux in that's in the back of the unit or if it would be an extra one and if so, mixed or how would it get selected? Don't really care, just curious...

Something else that caught my attention, the other populated connector on the replacement motherboard... Same side as the BT board, opposite corner (if that makes sense) that little corner of the board is just a little different from mine (unfortunately [MENTION=1915855]KID52[/MENTION] 's picutres had a ribbon right in front of it)

The replacement board has a connector there, unfortunately I can't see too much detail in the pictures I got from the ad, but on mine I have a trace with "Ant 1" printed on it, it seems like an on pcb antenna, kind of like the one on the BT PCB... Also, there is a pad with "wifi_+3v3"... That whole section is marked "IC1"... I guess a provision for built in wifi? possibly has something to do with unpopulated IC7 and IC17...

Also strange, these pads

Marked "IC6" Rather than "Conn #"... Integrated Circuit? Strange arrangement... The other side of the board is under the android daughterboard, not quite the edge of it... I'd be surprised if they connect on the other side, but can't tell.

As for the rest of the screenprinting....

No other pads under the tape.

Note the chinese quality control with the solder on traces by the daughterboard...

Sorry for the quality, lighting is not the best here the board is staying out for a while, any further pictures or any question, just ask...
[Android General] gpmg762:
Can you help to post a sharper photo of this spot.

I am trying to make out mic+ and mic- points to solder a mono 3.5mm female connector for external mic, thanks.
[Android General] donaldta:
Would it help if I colored them for you? And, if you're going to open then wouldn't you be able to see it first hand?

Btw, it might help to download the original size (2448 x 3264) of his photos. They're downloadable from his Flickr album
[Android General] chris.r.r:
Great, let us know if you were successful. Seems to be not a big deal to connect an external mic. Hopefully it switches automatically between the internal and external mic.

BTW, is it easy to open the unit? Or are there any precautions to not open it ;)
[Android General] sciallo:
*trying* to follow traces from those pads, I can tell they do connect to the ribbon that connects the faceplate, also worth noting that's the underside of your board. One thing that might not be too clear by looking at the pictures is just how tiny these test pads are. Not impossible to solder to, quite doable actually if you have a small iron and a little experience, but given a choice when it's time for an external mike, I'll probably just opt for an easier spot:

And plan on disconnecting the built in mic.

Soldering a mic. on those pads would not make the unit switch between the two. it would be like connecting two microphones (your new external and the pre-existing) in parallel... not ideal IMO, you're kinda messing up the whole impedence thing :rolleyes:

I would like to know how the units that have a connector through the harness handle that...

The unit is easy to open. once you pop the top cover off (3 screws), you'll see 4 screws holding the DVD drive, after taking those off, lift it *slowly* paying attention to the ribbon that connects it, you'll want to flip it to one side so you can disconnect that. (it's connector has a brown tab you click outward in the direction you'll be pulling the flex cable out with your fingernail).

If you do want to get the board out, you'll want to unscrew the amplifier from the back plate first recovering the metal retainer, then take the rear part of the case off, then finally unscrew the board from the bottom of the case. (easier done than explained) The first time around you might have enough thermal paste you can recycle from around the contact area of the mosfet amp, or you might want to have a tube handy. No need to go buy the $20 silver stuff for processors, any thermal paste from radioshak should be good enough.
[Android General] sciallo:
Oh, you made me feel dirty then...

So, any thought on the rest of the pads? rx and tx still the best possible candidates for some testing?

Few more considerations:

- Note better shielding between radio tuner and it's antenna plug on the replacement board, I wonder if that bears any noticeable signal improvement.

- I would like to know how the USB ports are connected on those units with two in the back and one in the front (if anyone with that type of unit ever has it open). I wonder if one connects to that connector by the whole wifi_v3v label..

- I notice only some of the pads have any significant amount of solder on them, as if they were temporarily connected in production? (doesn't seem too efficient to me) namely, the Rx pad has solder on it, the Tx doesn't.

Just killing time looking at it while I wait for an adapter and ultimately a replacement board...
[Android General] donaldta:
Well, those two plus the other pair on the ARM PCB that you pointed out earlier. Those are the only obvious that I'd try. If I had a JTAGulator I'd just plug it into all the open pads and let it "brute force" test all the possible connections.
[Android General] gpmg762:
:good:Thanks, that is a good spot to tap from. I will probably cut the wires, extend them outside the casing to JST plugs so I can switch between internal and external mic manually.

I have already tried the connector through the harness (added pin receptacles myself) from http://xdaforums.com/showpost.php?p=48818423&postcount=679 but it didn't work for me.
[Android General] sciallo:
Looking at this pick closely, he mentions connections for mic. on #6, but it looks to me like they're connected to #5 or am I wrong? Did you try both? or which?
[Android General] donaldta:
It looks like Black #5 and Clear #6 from the Microphone. The only white wire I see there is #2.

---------- Post added at 10:46 AM ---------- Previous post was at 10:27 AM ----------

Have you tried to trace where those pins would go on the actual board? Either they have different revisions of the board or somebody might have shorted the connection internally from the previous picture you took of those mic wires or a trace that lead to them.
[Android General] sciallo:
Not yet, I will later. That will be fun as it's on the opposite side of the board :)
[Android General] sciallo:
Ok, I started looking, going cross eyed :)

Camera actually works better than a good magnifying lens. I'll hopefully have some to post tomorrow. The numbering in that picture is in pairs, if I understand it right, the two mic. wires are on the same pair either 5 or 6, looks like the white (transparent) is on the top pin, black on the bottom. Would help if [MENTION=2678656]ThePapabear[/MENTION] could confirm which ones, maybe the picture without the red arrows might be enough to see clearer...

I guess I'll have 4 traces to follow :) they cross from top to bottom of the board a few times, so it will take me some effort when I have some time, hopefully tomorrow.
[Android General] ThePapabear:
Hi!

Excuse me for not answering faster, but i did not see this thread before (and was wondering, why i get mails about quotes, where are none to find...:silly:).

Cables both go to 6, i added a little larger version of the picture and without any arrows. ;)

Hope this helps a little bit.

Greetings from Austria!

ThePapabear
[Android General] donaldta:
Hmm... that actually makes it more confusing. Are you sure there isn't at least a third wire? Two wires going to the same pin would be a short. This would be understandable if they were combining left and right channels. However, there would need to be at least one additional pin for ground. Have you tested the microphone? Does it actually work?
[Android General] sciallo:
As I said, he numbered columns on the connector... they're numbered in pairs...

1 2 3 4 5 6 7 8 9

1b 2b 3b 4b 5b 6b 7b 8b 9b

So If I call the bottom row "b"

tranparent on 6

black on 6b
[Android General] ThePapabear:
Yes, that´s right!

Excuse me, but i thought this would be clear enough if i do the numbers above for the pairs of cables.
[Android General] donaldta:
Okay, I get it now...

I had to read two separate posts to get that it was top and bottom. Even though the first post said "fourth" not "sixth" but that is just a matter of which way you count; left to right or right to left. I had only been reading the last post with the picture attached.

At first, I was like, "Wtf, is there some sort of secret invisible Australian dialect I failed to see?"

<3 Next time do me a favor and describe it as "the 18-pin socket on the left with the microphone's transparent wire on pin 6 and its black wire on pin 15." That would have cleared up the confusion because pin "pairing" isn't always up and down.
[Android General] ThePapabear:
OK, i will remember that!
[Android General] sciallo:
Ok, here is the rundown on 6 and 6b trace following...

After following traces on both sides of the board, here is where I landed:

First thing they both go through is a 100ohm resistor right by the connector,

There is one unpopulated "resistor" pad set (R131) that could very well be a "0"ohm, but I don't know that... Also, R58 is no resistor, infinite resistance...

I did against my own advice, confirm my findings with a meter up to this part of the board.

Also, see the full size img where I circled where they *would* continue on to the front face flex cable and the mic. pads.

I still don't understand how pluging the mic to the rear connector would magically "deselect" the built in one with this wiring...

My opinion stands, as much as it would be possible to populate those pads and make the rear connection work, I'll probably opt for a dirty swap right on the front face pads where the built in one is soldered (unless I end up with a board that has this option "enabled" already).

Sorry I didn't get too detailed with it, you can go to the flickr album if you want to see all pics that lead to these conclusions.
[Android General] sciallo:
USB to serial adapter came in today... on to solder sone leads to the board :)
[Android General] sciallo:
Preliminary TX RX pad tests

Ok, I connected the rx, tx, and ground pads discussed earlier in this thread to this adapter. Tx to RX and Rx to Tx as described in this article...

I haven't yet found a setting that works. So far I've been trying various baud rate speeds with 8N1 hardware flow control - NO software flow control.

I had some speeds do more than others but no setting that would return character for character... most times i press keys on the keyboard and I see nothing or in some cases is see scrambled type characters, some speeds will return the same character as I press every now and then...

for example I just typed "zxcvbnmnbvcxz" and the screen printed "z��vnln���x�"

The usual stuff you get when you're trying to figure out the settings... Here what is interesting about this first attempt... The only time I get anything on the screen in terminal program when I push keyboard buttons (using minicom on linux) is when the unit is off! If I power it up it just stops, when I turn it back off it will return garbage on the screen again... Here is what's even more peculiar: it does the same if I pull all power off (ie disconnect the power plug alltogether) at first I thought it was at least still getting power from the main 12v. wire...

Now, following the advice of the article I didn't connect any of the 5v or 3v pins from my adapter, just Gnd2 Rx and Tx, it's trying to communicate with an unpowered device with some sort of something happening?

Something else to keep in mind is that this board not only no longer has a working MCU but it's also not booting anything at all so may be fried completely or who knows...

Wondering if I should try to connet 3v or 5v from my adapter to the Pwr pad...
[Android General] donaldta:
That is certainly very odd. Not sure if you should add your own voltage. One would think those were there for measurement purposes.
[Android General] sciallo:
As I mentioned, it looks odd that some pads look like they have leftover solder while others are bare.... almost as if they loaded eprom firmware that way in production, would make sense to not have to power the board up to do that. interestingly enough GND PWR and RX have solder, TX doesn't... ??
[Android General] gpmg762:
Just to update on the external mic, I cut the red and black wires (credit goes to sciallo's pictures) joined new ones running out to 3.5mm female plug to connect a condenser mic and it is working great.

I removed the screen and took a peek at the internal mic, it is only 2-3mm in diameter, no wonder it sux.

The pins on the harness didn't work for me.

P.S. while removing screws to the disc drive, there are 2 metal washers which raise the height of the drive in the front. Without them, CD will not eject properly.
[Android General] sciallo:
Cool, Glad you got it, if you took any pictures it would be cool...

I didn't have any washers there, but thanks, that's something to keep a look out for when disassembling a unit.
[Android General] ackyo:
what mike did you use? i have one from a parrot kit lying around somewhere here
[Android General] gpmg762:
Just a normal clip mic.
[Android General] Android_ski:
hardware questions....

1. How is the quality of sound when playing a music cd?

2. If i disconnect unit from battery, will it reset/loose settings?

3. What firmware is the most stable where everything works and doesnt crash reboot etc...
[Android General] sciallo:
1. I hope someone else can answer, I haven't tried CD and my unit is apart. But in general the sound quality of the unit has been reported to be pretty good, better than stock units.

2. If you disconnect main 12 v. (there is an acc wire to shut off) you'll loose time, FM memories and generally settings that are stored in the MCU, not any of the android settings. Also I believe any bluetooth settings are stored in a permanent way so you shouldn't loose any of that (address book, pairings etc.)

3. Not really a hardware question. I think all but .23 and .68 are pretty stable some minor things don't work on the early ones. See first post on the main thread for changelogs and maybe ask for a second opinion there, where there.
[Android General] donaldta:
Technically, those are not hardware questions related to this thread and most have already been answered in the main AN-21U thread.

Btw, there's no way to get loose settings but there's also no way to tighten them either. :silly:
[Android General] Android_ski:
Will i need to root my unit before i can apply .70?
[Android General] donaldta:
Damn<capslock key broke

NO AND THIS IS NOT AN INAPPROPRIATE PLACE TO ASK. YOU SHOULD POST THESE QUESTIONS IN THE MAIN AN-21U THREAD.
[Android General] chris.r.r:
[MENTION=586971]guano30[/MENTION] wrote in the other thread that the volume of his external mic is again too low. Does that only apply to the built-in mic jack, which comes with the harness? Or is it a general problem, that there should be some mic amplification on MCU side? What's your experience with the volume of your external mic? Would like to solder a 3.5mm jack onto the original internal mic pads...
[Android General] :
Hi,

hope this is the right threat for discussion about the firmware files, i think in the "main" AN21U-thread isn't the right place.

What effort have been done to decrypt the firmware?

Does anybody know how they compress the files, because i think it it is possible that the password for the encryption can be the same as the on for usb-debugging.

i ran the firmware through binwalk to search for file signatures and i always get al lot of zlib-compressed files...

Since i don't have any expirience in decrypting firmware files an so on i don't know what i can do with this, perhaps someone with more knowledge in this topic can help

EDIT:

Just found the manual for this unit an there it says:

3.3 Update system

3.3.1. copy "u-boot-skip.bin、uImage、uramdisk.img、

system.img" to the root directory of SD card，and Inserted into

the machine SD card slot.

Perhaps the Update will also work with unecrypted files?

Link to the manual: http://betopseller.com/img/dvd/new-android-manual.pdf
[Android General] donaldta:
No. Not really. The easiest way to differentiate between the two threads is that this specifically relative

HARD

WARE hacks. Meaning a physical component, like a wire or a resistor being changed or altered to change the functionality. Firmware is a software component therefore belongs in the main AN-21U thread, and I believe was even discussed in the earlier pages.

Is a password even relevant? It seems to me it would be easier for them to use key pair encryption for this process, instead of a password which is really meant for people interaction. The point of the matter is that we do not know. It may not even be encrypted at all. They could be a images written in a way the standard public tools aren't able understand. Until someone can define or explain it, this process is "magic" as far as I'm concerned. You put files on a SD card and fumble with the front panel and viola something changes.

Well, it is obvious which one is the system.img. That will be the largest one, "8e3513e2-ea4a-11e2-8a0f-000c29ba27c0". I don't know why they are using 128-bit UUIDs as filenames but I suspect is to prevent the updates to be applied to the wrong variant or even the wrong model. If it is a possibility then you could use unencrypted system.img with that name to test it. As long as you don't touch the other files, it should be relatively safe, since you can just replace it with a known working image.

I've never attempted to create my own ROM but if you're interested here's an article, "How to cook your own Android ROM that might help if you're interested in pursuing such a venture.
[Android General] gpmg762:
The volume of the external mic is probably the same but the improvement I have is really the position of the mic.

My car is right-hand drive, having the mic right in front of me beats the internal mic on the passenger side picking up noise.

Don't think there is much we can do about amplification on the MCU, software approach maybe worth looking into.
[Android General] chris.r.r:
Friday I'll start my project "microphone" together with a friend who is hardware engineer.

Our plan is to connect a 3.5mm female jack to the internal mic pads of the unit, which I then connect to my external microphone in the car.

We also thought of putting a preamp in between, but we are unsure if the amplification wouldn't be too strong (amplification 150-1500 fold) for the unit... Potentially you'll reach the clipping limits of the hardware which would make it even worse. Usually those preamps are made for a different purpose, right?

[MENTION=586971]guano30[/MENTION] haven't you used an external mic preamp?

I post some images and experiences once we are done...
[Android General] donaldta:
Why the mic solder pads and not the already included wiring of the internal mic?

I have a question about that circuit since all the manuals are in languages other than English. The specifications indicate the operating voltage for this circuit is 9 ~ 27 VDC and consumption is 7 mA. Yet, the input voltage is 100 mV which I assume is supposed to come from the inputs. So, exactly where is this circuit supposed to get the power from? Passive microphones don't have power and I've yet to see anyone use an active microphone with this unit.

P.s., I believe [MENTION=586971]guano30[/MENTION] was chased away because of his inability to communicate and use the search tool. I doubt you'll ever see him again.
[Android General] chris.r.r:
Because then I would have to cut the wires and warranty is gone... By soldering it to the pads I would hope to make it somehow undoable in case that a hardware problem arises in a later stage... Are there any seals or similar stuff?

As I understand it, you simply connect 12V to the preamp, e.g. from the blue wire for the antenna amp. The input of the mic must be between 0.2 and 2mV... no idea, if my mic fulfills this requirement...

is the guy still offended? ;)
[Android General] donaldta:
Interesting. I guess cut wires could be easier to spot. Either way your warranty is gone whether or not you cut the wires or put solder on the pads if they detect it.

There are five posts on the circuit. Would you mind pointing out where you would make such connections?

Well, the last post in the XDA forums is a somewhat dramatic and misguided farewell. I suspect his pride is hurt and probably won't ever resurface. Might be silently reading posts though.
[Android General] sciallo:
My bad... :/

What I would do/plan on doing is desolder the existing mic. and solder to those pads (picture a few pages back), [MENTION=5389783]donaldta[/MENTION] , I think he's talking about those pads, not the test pads on the opposite side of the board. Those already have solder on, resoldering the original mic. if done right could be ok. There is a "warranty void" type sticker on the cover, but many times it's already cut, I returned my ouku after opening it and it was not an issue.
[Android General] donaldta:
I wouldn't worry about it. The guy was kind of nut job anyways. He tried to place the blame on not being technology savvy and not speaking English but that is completely absurd. I've helped countless of people whose technical skill was stretch by pressing the on button and English wasn't even the second, third or fourth language.

If you check Page #186 of the main thread, 80% of the page is a conversation between [MENTION=586971]guano30[/MENTION] and [MENTION=5617942]tarzansg[/MENTION]. In which case, tarzansg mentions MCU not once, not twice but three times in his explanation to guano30. Three times. Now I don't know about you but if I don't understand a word, phrase or even an acronym mentioned to me then I'll try to look it up or at least ask about it. The last thing I would do is to make up my own definition and continue the conversation as if I knew what it mean.

He then continues to try to say that he didn't know to look up MCU in a search. WTF does that mean? If I don't know what the word "schadenfreude" means then I don't look up "fahrvergnügen" or pretend it means "breast enlargement". If that doesn't beat all, he continues to talk about "someone" told him to use shell commands and he didn't know. You know who that was? Post #1818. You don't even need to click the link it. Yes, it was me and I was trying to help him with his problem and when I asked follow up questions to help him you know what he did? Ignored me completely.

So, don't worry about it. When you wrote that really long post of your frustrations, I think you spoke the mind of what a lot people were thinking. He know it. He was embarrassed and tried to blame it Obama and the NSA. He's gone and you know what? I honestly don't think anyone misses him.
[Android General] sciallo:
LOL, thanks!

(though there was a hint of sarchasm in that "My bad" I haven't really lost sleep on it...)

Seems like as expected the long post did nothing other than getting things off my chest. We still got questions popping up that have answers on post#1, pages of microphone USB hubs and hardware stuff in the main thread, and that's ok, I figured people are liking just one thread to follow (?) but funnier, software questions here LOL... oh well, let it grow, I can deal with it.

BTW I started a page on MCU, your analogy with the remote control nails it with the "native apps", I will quote it verbatum if that's ok (with credits of course :) )
[Android General] donaldta:
Yep, we all have to vent sooner or later. It may not do anything but it feels better not to keep it bottled in.

Sure, no worries. It'll be nice to have something to point to when people ask.