yashsingh1/xdaforums huggingface dataset:
[Android General] chris.r.r:
Correct, that's the plan... Thanks for pointing that out.
[Android General] tarzansg:
external mic

donaldta,sciallo

you guys are right, my bad to post the stuff about build.prop, I eventually realized its does nothing, the small improvement that were mislead by my call partner feedback to me that my voice is clear and loud, so i never posted again in the original thread to avoid others mistakenly following that. I wished i could re-call that just like my outlook email. Now i have bought the necessary hardwares to support the mic hardware project that many of you have talk about and some already completed that mic project. So i get myself ready with the 3.5mm female and some soldering iron, i waiting to find some spare time to work on that, will be back to post some pics and result once i am done. My unit is already inside my car dash, so it will be more challenging now to work on this project compare to previously the unit on my desk.
[Android General] donaldta:
As a pre-cautionary step, you might consider going back to the post and edit it with the tags so someone doesn't actually try it after finding it in search. Or just remove the references to build.prop altogether.
[Android General] tarzansg:
Just to add, i also bought a switch/toggle, the objective is to allow me to switch from the signal source either from the internal mic or external mic depending on if i am the one talking or my passenger is talking, for my case driver side on the right will use external mic, passenger on the left will switch to internal mic on the unit. Thats my intention, but i am not sure will it work, i will know when i start to work on the project. Here are the picture on the hardware that i have just purchase.
[Android General] tarzansg:
Got it, good idea ! will to the follow-up...
[Android General] donaldta:
Honestly, mics that you would use for this purpose are directional. So, the design of having the mic built into the unit is a horrible design unless you are sitting in an environment with very little noise. In most cases based on the position of the radio, unless your passenger is midget trying to give you head while talking on the speakerphone the internal mic is pretty useless.
[Android General] Android_ski:
That switch is huge!;) you van find exactly the same thing, but a micro switch 1/5th the size;)

But it should work just fine.

---------- Post added at 04:34 PM ---------- Previous post was at 04:28 PM ----------

Just checked ebay, do a search for "micro toggle switch", there is a picture there in the search results that shows one besides a penny. That will give you an idea why i said "huge". And again...there is nothing wrong with the one you purchased:)
[Android General] donaldta:
I'm reposting [MENTION=3066536]TOMMYX2[/MENTION] message from the main thread.
[Android General] sciallo:
A consideration on shielding

To anyone that's wanting to hardwire an external mic., I would think of keeping the mic line shielded once outside of the unit.

Personally I plan on using shielded wire (same wire as you'd find used for a pair of headphones, coax, one or two conductors shielded by a outer copper jacket/mesh) even for the connection inside from the pads to the female jack. If the female jack is panel mounted right on the unit it's not as crucial as the body of the radio itself provides shielding, though with BT transmitting and the amount of "electrical stuff" going on even in there I would feel better. Outside the unit... absolutely. Mic connection is low lavel, it should be shielded or it will pick up noise from all electric equipment just like an antenna. Same reason RCA amp connections are shielded...

If you where to put a toggle switch (probably unnecessary with good placement of the ext. mic. if you ask me) you would want to shield that too, maybe enclose it with a metal project box in the back.

Just food for thought.
[Android General] tarzansg:
Great info to know, and thanks for sharing. The shielding would ensure sound quality being maintained. So i guess another reason for the switch is because i still be able to maintain the functionality of the internal mic by introducing the switch. I will now think about how i can shield up the back of the switch.

---------- Post added at 10:51 AM ---------- Previous post was at 10:44 AM ----------

Noticed there are 2 mics from TOMMY's post, if i correctly seen from the pictures. Not sure if 2 mics functional at the same time would help?, as i read about the impedance issue that all of you have mentioned. Same reason why i am doing away with my current setup, one internal mic, and the other external mic from the harness, both operational at the same time, but voice level very low on the external mic.
[Android General] Miwer:
Idea for external mic.

Hi there,

Just wanted to contribute with my idea of an implementation for an external mic.

I would like it, so that when an external mic is plugged in, the internal mic is automatically disconnected, and vice versa.

In order to do that, I would need a female jack connector, that has internal "bypass" connections (don't know the technical term), that opens, when a jack is inserted, thereby disconnecting whatever is connected to it. These types of connectors are very common, and should be broadly available in electronics stores.

Well images speak louder than words, so I made a little schematic, and found a connector with datasheet, to illustrate my idea.

WARNING:

This particular connector has the shield connected to the threaded metal mounting barrel, so it is important to check that one of the pins on the mic is already connected to ground (and chasis).

Since I don't have one of these units (yet, perhaps) I cannot check this. Maybe someone with a unit can check this.

If none of the MIC pins are connected to ground, you should use a connector, that don't connect the shield to the chasis.

Have fun :)
[Android General] chris.r.r:
Sorry, [MENTION=5389783]donaldta[/MENTION], I overlooked your question...

That would be my first guess:

The left side of the preamp (two pins) seems to be for the mic input, so I would connect the red and black wire of the external mic to the +/- pin of those pins. On the right side of the preamp there should be +Uv, NF and -. So I would attach the 12V wire to +Uv and Minus to ground. Then I would attach the mic with red to NF and black to Minus. I'm not a hardware expert, so I'm not sure if that makes perfectly sense. That's why I took a hardware engineer onboard ;)
[Android General] donaldta:
Thanks, I appreciate that. The manual for the pre-amp is not available in English which is why I was curious. I'm glad you got someone whom knows what they're doing. This is what I feared hadn't occurred when the "other person" tried to use it. Since they claimed not to be technically savvy even though they probably understood Deutsch which the main manual was written in.
[Android General] sciallo:
I just checked ground to 'mic -' with a multimeter and can confirm 'mic -' goes to ground as expected for shielding.

Thanks for the post, that would be the proper way to connect so that when unplugged the internal mic takes over again. I thought of doing that too and I might but I really don't think I'll care for the internal mic. to ever work again once I have the external one. and it's not like it's easy to unplug anyway...

Another consideration, some cars have very little room in the back, to the point that a straight plug from the microphone would cause the radio not to go in all the way, so anyone looking at doing this, take a look at your dash depth in the spot you plan on mounting that panel female. Or just come out with a shielded wire with a female at the end.
[Android General] chris.r.r:
Usually mic cables are not shielded (correct me if I'm wrong), and mine is about three meters long. Do you really think shielding the 15 cm wire from board to female jack provides any improvement here?
[Android General] donaldta:
Incidentally, the photo and schematics of part that you attached is the Philmore 3.5mm Phone Jack, Part# 502J. It is a 3 conductor jack that uses tip, ring and sleeve which is meant for left, right and ground respectively. Although you can ignore the ring and use the tip as mono and sleeve as ground. The nice thing about that particular connector is that it has a manual switch mechanism with two additional posts. This allows you to switch the outputs with the presence (or lack thereof) of something plugged into it.

There are also a several non-switchable panel mount jacks they produce like the 504K for 3.5mm "stereo", 702JP for 3.5mm "mono, 666JP for 2.5mm "stereo" and 660JP 2.5mm "mono". Here are the isolated versions of these jacks as mentioned in your post; 70-524 3.5mm "mono", 70-534 3.5mm "stereo", 70-626 2.5mm "mono" and 70-636 2.5mm "stereo". Their online pdf catalog has relevant pages to these jacks on Page #59 & 60.
[Android General] Prdie:
My AN21 is on the way with default OUKU fascia - two silver knobs. I have not seen them in real, but I think they'll look cheap. Do you think it would be difficult to change just the knob ?
[Android General] sciallo:
I was trying to do a quick google search to find a better reference on shielding and to show that microphone cables are indeed shielded. I didn't spend too much time on it, maybe I'll find something better later, but most what I found, doesn't try to convince me to get shielded wire, it goes straight to help me choose the type of shielding (in our application, I would call that splitting hairs)...

Just one random example page.

When it comes to audio, you're transporting frequencies, the only time we don't worry about shielding is after that frequency is amplified, for example the wires from amp to the speakers.

First of all, let me clarify, I'm not claiming any 'improvement' using shielded wire, it will not give better gain or 'louder' signal. I'm avoiding "UN-improvement". I'm trying to keep noise out of our signal.

As I said before, inside the box it might be ok as the box itself is metal and is grounded for that very reason. I will still use shielded "headphone type" wire just so I don't get surprised by hissing noise from the fan spinning for example, or pops and clicks by whatever switching at the board or noises from the BT RF (the antenna for BT is nothing but a trace printed on the top part of that daughterboard right underneath our mic. connection)...

Once outside the box I sure hope that 3 meter long wire connecting your microphone is shielded (doesn't have to be big, like I said headphone wires are shielded) or you'll start including wistles from your alternator changing with your RPM and what have you to your voice.
[Android General] Miwer:
That's true - it's not like it's meant for an easy internal/external switc for the mic. My reason for doing this would also only be for future remounting-in-another-car or selling-because-i-got-a-new-one type of scenarios :) Once an external mic is installed, I'm not likely to ever want to use the internal mic again, but if I some day need to disconnect it, I wouldn't have to dismantle the unit again in order to reconnect the internal mic.

I would recommend people to look for those 90 degree angled jack connectors. They won't stick out much. Maybe strip one off an old set of earplugs, and resolder to an external mic.
[Android General] sciallo:
Or even if they don't :)

MCU Page is up at:

http://xdaforums.com/wiki/Generic_Android_Head_Unit/MCU_Explained

It's not linked to from other wiki pages yet, give me some feedback, constructive criticism (or destructive if need be), corrections, questions requests for expansion....

Will link from other wiki pages in the next day or so.
[Android General] flyboy1100:
Does an external Mic work with this unit. I see the discussion,but is it better than whatever is included?
[Android General] Android_ski:
Strangly enough i have spoken to three people over BT and none of them have complained over the quality. I think i will be passing on the mod myself. Maybe they changed something in these radios recently? I also will be passing for now on the Firmware, upgrading seems to open up a can of worms
[Android General] ThePapabear:
I have a big difference between the internal and the external microphone. Internal is crap, as you would expect it, but the external (which i was getting with my unit and the connector is at the harness) works really not bad. Good enough, that no one which i was talking to while using the microphone had a problem to understand me (except some connection problems to the network at my home, where it is very poor).

Only BT connection it self is at least buggy. Sometimes it works perfect, but often i have to reconnect or i can hear anything, but my phone partner could not hear me. If i have to use this every day multiple times, i think i would not have the unit for a long period of time...
[Android General] flyboy1100:
Which exact one do you have?
[Android General] ThePapabear:
I own this unit (exactly from this seller), which brand the microphone has, i dont know, because it came with the unit and i could not find any text on it. Is a little bigger than it could be, but that´s not a deal breaker for me. When bluetooth connection is stable, it works at least as well as my old parrot ck3100 did.
[Android General] vwpassat3c:
About microphone

Hi, I looked at the microphone for "Parrot ASTEROID SMART"

here is how it looks beta.hstor.org/storage2/adb/0db/be0/adb0dbbe0ad608255d45203d1fd39bc2.jpg

at first I thought they had a stereo microphone, after I thought there was, I think Parrot have two microphone one for android and one for handsfree. I hope someone will understand where I'm going. Unfortunately I do not speak English, but I'll try to ask on the russian forums, if I'm right about the mic or not, if anyone wants to ask the same thing in the thread of the parrot. I think this is the problem because the microphone does not work well in the Android app. In my opinion when the microphone is activated by the app in Android given that he is directly connected to the handsfree there a leakage current or at least some interference. This would explain why the users who have connected an external microphone had improvements only on the handsfree and not on the android.
[Android General] donaldta:
I have the Parrot Asteroid Smart. Yes, the external microphone actually has two separate mics. Each individual mic feeds its pair of wires into the 4 conductor 2.5mm phono jack. It doesn't use one side for android the other side for handsfree. This microphone was specifically designed to be used with Parrot's Noise Reduction DSP-3 technology. It uses a special algorithm to block out environmental background noise from either microphones. The microphones inside this particular assembly are also directional and for best performance should be pointing at subject's subjects mouth area.

If you ask me this is probably the wrong type of microphone to use use with the AN-21U and probably the single mic version would probably be better. Besides, I doubt that the AN-21U has any of the Parrot's noise reduction technology required for the dual mic to operate optimally.

The issue in my opinion is how the MCU's handles the microphone for the handsfree Bluetooth circuitry vs how the Android board handles it. Because a couple of people; like [MENTION=1255922]ransu[/MENTION] and [MENTION=5617942]tarzansg[/MENTION], have noted in the main thread that the voice recording app in Android is loud and clear.
[Android General] djblaze852002:
Blinding Blue LEDs

I hope this is the right place to be asking about this. The bright blue LEDs are blinding me at night. I want a way to fix this issue. I am not great at soldering, so replacing the LEDs is not something I think I can do.

I thought about placing a color "gel" (piece of colored clear plastic) over the LED to reduce the brightness and perhaps alter the color. Maybe adding some red tint would make my buttons a nice darker purple? I have looked though all of your pictures, but it seems like you have only cracked into the main compartment of the unit where the motherboard is. I think I need to get between the front fascia and the LCD screen if I hope to reduce the brightness of the LEDs in any way.

Has anyone gotten to these LEDs? Does my logic sound right? Is there any other simple, foolproof way to remedy this issue?
[Android General] sciallo:
Which unit do you have? (1 knob, two, car specific...) ?
[Android General] donaldta:
I could be wrong but according to Post #438 of the main thread, he has the single knob version from this eBay listing.
[Android General] djblaze852002:
Yes I have the single knob version. I just need some way to reduce the blinding blue light. Looking for any ideas form those who have taken their unit apart.
[Android General] chris.r.r:
This weekend I tried to connect an external mic to my AN21-U (VW version). But the faceplate seems to be quite different, because I didn't found the mic pads in the front area of the unit. Unfortunately I forgot to take pictures :eek:

I put the top cover off and lifted the DVD drive, but no visible mic pads anywhere.
[Android General] donaldta:
I take it then you didn't find the internal mic at all or where its leads solder onto the board? You might require a deeper disassembly due to the difference of the faceplate.
[Android General] chris.r.r:
I didn't find the place where it's soldered to the board - seems to be more hidden than in the universal unit. I was not brave enough to dissamble it deeper because of the highly sensitive parts like display and touchscreen in the front area... I will wait for someone with more sophisticated knowledge than me... ;)
[Android General] ackyo:
hmmmm ok so i will not be modding mine this week.......

i am happy to pull mine apart to investigate this microphone mod on the VW version. I was planning on doing it this week (big trip coming up this weekend), seeing as its a bigger job than the universal unit i wont get a chance to look at it until at least the 16th now, will grab pics etc as i go.
[Android General] jpapadami:
USB Mic Adapter

Hey All,

I saw a lot of people in this thread interested in having an external microphone for their car stereo. I am also in the same boat. Do you think that a USB Mic Adapter might work with these Android units?

I plan on finally getting this 7" Pure Android car stereo. They are willing to produce one with Red LEDs and a DVB-T for a fee, but don't want to install an external mic jack. I know I can do it, but I don't want to void the warranty.
[Android General] sciallo:
I wouldn't worry about the warranty. It is worthless anyway. If the unit fails or is defective within the aliexpress policy time for return, they will take it back wether you opened it or not (they took mine), past that point you're kind of on your own (I'm finding out the hard way, I can't even seem to get them to sell me parts). I guess you could send the unit back for repairs under warranty, but that's about $80 each way in shipping....
[Android General] jpapadami:
Thanks for the reply. OK then,

1. What is the aliexpress time frame for return? Have a hard time finding help info on their site.

2. Where can I find or what keywords should I use to search and find such a external mic such as the one in Post#74
[Android General] sciallo:
1 I believe it's 15 days return. They do claim to offer a 1 year warranty but that's what we talked about.... If they make good on it the fact your unit was opened wouldn't matter. They encouraged me to try to repair locally before I returned my first one, and by the way the sticker was already cut clean :)

2 No Idea. I pulled a microphone out of a Jaguar at the junk yard :) For what I remember reading here the parrot doesn't really work well with this unit as it was designed specifically for parrot units and seems to have different impedence.
[Android General] jpapadami:
Well, I was able to find a desktop 3.5mm Mic headphone Front I/O Panel for a pretty cheap price that will do the trick in case some else is interested.
[Android General] sciallo:
Oh, for that part, radio shack has female 3.5mm plugs, panel mounted or not (in case you don't have too much room behind the unit) and if you read a few posts back, I plan on using shielded wire (same as headphone wire) for it just to make sure I don't pick up any noise.
[Android General] hidraq:
Which model of amplifier installed on headunit? How i can replace amplifier on another model for better sound?
[Android General] sciallo:
I would use external amps connected to the prreamps out. The built in amp is a single mosfet type chip (I believe)... I am traveling ATM I can see what chip once I get home next week...
[Android General] juliomc02:
Hello there, I have VW version and also trying to do the mic replacement. I want to use the mic that i have installed already from the oem bluetooth from VW, so i managed to trace down the wires of the mic. It goes from top, where the mic is located, to under the passenger seat, where the bluetooth module is. What I initially did was to use 2 wires that are no longer in use from behind the unit that go to the bluetooth module to joint those 2 with the 2 from the mic under the passenger seat, and then use those 2 wires behind the unit to inside the unit to the mic where I unsoldered the wires of the original crappy mic of the unit. The result was that the sound was better , but only is tooooo low, i had to scream so the other person on the phone could hear me, but compare to the quality (with the original mic is like you are talking with no good network coverage even if you scream) is way better. So i'm guessing may be is to much wire conections?? If I run a wire from top from the VW mic directly to unit would this improve? or am i missing something?
[Android General] ackyo:
ok as promised completed the mic hack on the VW version of the head unit, i used a mic from an old parrot kit i had lying about.

to get to the mic solder pads you need to undo the 6 screws holding on the screen bezel etc.

heres a buch of pics of the unit apart
[Android General] juliomc02:
Did you solder to the board? o somewhere else? I soldered a wire and then to the VW original mic but the sound is to low, how is your sound quality, how other people ear you?
[Android General] ackyo:
I soldered directly to the board - to me that's easier than cutting wires soldering and heat shrinking them.

So far I have only tested parked in the driveway with the engine off but apparently it's a massive improvement
[Android General] juliomc02:
I found a mic so used that one instead of the VW and now it works great, that VW mic must use some kind of amplifier when it goes through the VW bluetooth module. I'll just place this mic in the place where the VW mic is and done, great improvement.
[Android General] Artur1990:
hi, i have VW version with canbus, and if I turn off the ignition but do not pull out the key, the the radio works a couple of seconds and then turns off, and then itself includes some time for a few seconds and off again, and so all the time.

what can be.

thank you
[Android General] Yippee38:
If you can get to the LED, try putting a drop of black fingernail polish on the top of the LED. I did that for the blue LEDs on my HTPC, and it worked great.