yashsingh1/xdaforums huggingface dataset:
[MTCD  Android Head Units Q&A] mattboy9921:
I have seen as well that some manufacturers will lock down what devices can be plugged into the USB ports. In my case, my unit doesn't seem to care. I use my phone via USB with Android Auto no problem and I've plugged in a flash drive and hard drive before with no issue.

There is just so much mystery surrounding the technical details of these units that it's hard to figure out what works anymore.
[MTCD  Android Head Units Q&A] cgwatson1979:
I have tried contacting more than one moderator trying to find out what the letters MTCD(E)/FYT mean. I understand that they are different types of Android head units but what makes them that type? I want to make sure that my posts are in the correct section. One moderator was adamant that the Bluetooth dongle wouldn't work. We may have been talking apples and oranges. I haven't had time to take pictures or a video of my setup. Didn't know this was such a hot topic here.
[MTCD  Android Head Units Q&A] marchnz:
MTCx = the prefix found on MCU type.

FYT = best explained in FYT forums.

All you need to understand the differences is here on forums.

Read up and post your findings
[MTCD  Android Head Units Q&A] ruinertt:
Under "Settings" > About machine, you will see an MCU section. The MTCx type will be listed.
[MTCD  Android Head Units Q&A] ruinertt:
Well?? :) I'm sitting here with anticipation of good news!
[MTCD  Android Head Units Q&A] mattboy9921:
I just tried it but no success unfortunately. I plugged it in, turned on the unit and the only Bluetooth I see is the built in one. Unlike the other one I tried, this one did actually light up so I know it was powered at least. I also went into factory settings and changed the BT setting to "NO", but after rebooting, Bluetooth simply doesn't work.

The options in the factory setting BT menu are:

NO

MD725

WQ_BC5

WQ_BC6

WQ_BC8

Parrot FC6000T

SD-968

SD-BC6

SD-GT936

IVT-i145

SD-8350

WQ_RF210

SD-816

My unit's built in Bluetooth is SD-GT936. I'm wondering if perhaps we need to find a Bluetooth dongle that uses one of these chips for it to have a chance to work with the unit.
[MTCD  Android Head Units Q&A] ruinertt:
IF you can get it to use one of the above firmware settings/drivers, you MIGHT get it to work. You need to find out more about the module that you bought. Perhaps it uses and/or is close to one of the kernel settings above. Which model is it, exactly?
[MTCD  Android Head Units Q&A] mattboy9921:
When I plug it into a Windows PC, it shows me a name of BCM20702A0 by Broadcom. I was thinking it might be worth trying going down the list I posted above with it plugged in to see if any of them work but it is doubtful.

I'm also wondering if there exists a dongle that expressly is one of the ones in the list. I've done a little Googling and it seems they are all references to the actual chip one would solder to the main board rather than a USB dongle.
[MTCD  Android Head Units Q&A] ruinertt:
Yeah, I was afraid of that, but that is what I am seeing as well. The trick, from what I'm reading, is to find a USB dongle that is supported in the Linux build's kernel natively...but that may be a far stretch.
[MTCD  Android Head Units Q&A] mattboy9921:
Sorry, I wrote a reply earlier but I think it was lost to the void due to server maintenance.

Anyway, I had said that the only one I've seen people say they have success with is the Comfast CF-WU725B. Looks like it would be compatible with the driver MD725. Unfortunately, that seems to be an old product and I can't find many places to buy it anymore.
[MTCD  Android Head Units Q&A] ruinertt:
I saw that, but wasn't that with an older version of Android? I dunno, maybe it will still work. I so want to get this bluetooth voice issue fixed. I can hear everyone perfectly, but they can't hear me for the life of them. They say that it sounds like I am far away with a lot of interference/background noise.
[MTCD  Android Head Units Q&A] mattboy9921:
I mean if the driver exists on the system, I feel like it might work. If we can find a place to buy it.
[MTCD  Android Head Units Q&A] marchnz:
Could it be the mic that there are 1000s of posts about
[MTCD  Android Head Units Q&A] ruinertt:
You'd think, but I've already switched them out as the first troubleshooting step. There is definitely an issue, but is it the mic? Is it how the internal/external mic connections on the board are placed with signal interference? Is it Android Auto? Is it how the MCU deals with the bluetooth module? I've read through so many posts I can't even keep up anymore.
[MTCD  Android Head Units Q&A] mattboy9921:
Do you have the issue where if you try to talk to the Google assistant in AA, it can't figure out what you're saying and it gives up? I've had that for a long time and I'm not sure if it is my mic because people hear me on calls (not great audio but communication is possible).
[MTCD  Android Head Units Q&A] ruinertt:
No, talking to the google assistant in AA is pretty much dead-on which is why I'm perplexed with the audio (sending via the mic) clarity during phone calls. Strange for sure. Granted, they CAN hear me, but I just sound far off (their wording). I really need to let my wife call me from my truck and see what it really sounds like...
[MTCD  Android Head Units Q&A] techo91:
That’s not good, I wanted that as well as my WiFi is also bad.
[MTCD  Android Head Units Q&A] ajp8868:
I can second that! I had exactly the same issues and resolved it with that dongle. Cost me £5 on AliExpress and arrived in about 12 days
[MTCD  Android Head Units Q&A] RazGame:
But what I should do if my HU already have MD725 and sound via BT really bad ?
[MTCD  Android Head Units Q&A] techo91:
Do you have the dongle or you are simply trying the setting?
[MTCD  Android Head Units Q&A] ikerg:
try the dongle...for 5USD it worths the trial
[MTCD  Android Head Units Q&A] raculpeper:
I just ordered the Comfast Dongle recommended above and and preparing to wait for its arrival. Not crazy about the ship time but cant complain given the price of the unit. I saw a newer Comfast on amazon...any reason why this wouldn't also work https://www.amazon.com/COMFAST-CF-W...1&keywords=COMFAST+Bluetooth#customerReviews? Only thing I could think of would be the driver but seems like should be able to install it somehow. Any thoughts are appreciated.
[MTCD  Android Head Units Q&A] bjt2:
So mine arrived a few days ago, I've since done a bit of experimentation with it, and it kind of works. If I cold boot the unit, the dongle is detected and works perfectly. However if it comes out of sleep standby (PX5) i.e. 99% of the time, it doesn't work and seems to default back to the internal BT. What could be complicating things is that the internal chipset on my unit is also an MD725. I'm wondering if I could possibly exclude the process for BT from closing to stop this?
[MTCD  Android Head Units Q&A] WarSpaz:
Ty for your experience. Have you tried to unplug and replug the dongle after standby? Just curious if it would get enabled then. Im about to install my hu this weekend, also got this dongle if my wifi/bt will be bad
[MTCD  Android Head Units Q&A] roly01:
How do you which one is working?
[MTCD  Android Head Units Q&A] bjt2:
The little blue light comes on. Also you can check the dongles BT MAC address.
[MTCD  Android Head Units Q&A] techo91:
For me it’s not working. Hangs the whole unit when it cold-boots with it plugged in.
[MTCD  Android Head Units Q&A] bjt2:
If I unplug it after its been detected it will hang the whole unit, and I have to hard reset. If it hasn't detected nothing will happen when I plug it back in.
[MTCD  Android Head Units Q&A] raculpeper:
It may be possible to use an application like this Bluetooth Auto Connect to prioritize which device is being used each time: https://play.google.com/store/apps/details?id=org.myklos.btautoconnect&hl=en
[MTCD  Android Head Units Q&A] akviberg:
hello, i bought a comfast and it work great, (original sd-968 in my unit) but it seems that the microphone does not work. any ideas guys?
[MTCD  Android Head Units Q&A] silo:
Hi

Recently I bought comfast CF-WU725B USB card, to see if It can be used instead of integrated BT/WIFI unit.

Mine MCU has md725, so as a BT HF unit it's useless!

Lot of "hishes", echoes, and sound quality like, when you will be almost to far from receiver.

But the problem is that when I plug this card to USB port in some time unit will freeze, and only reboot helps.

I can tell that drivers are get loaded, cause card LED start's to glow.

But when I disable BT from Factory Settings I get no BT, no WIFI and when I connect this card to USB its drivers aren't loaded (no LED light on card).

Is there anyone here that tested this card with success?
[MTCD  Android Head Units Q&A] akispavlopoulos:
You have written wrong model type. The comfast cf-wr302s is a wifi repeater! Please write the correct model of your usb card...
[MTCD  Android Head Units Q&A] silo:
Sorry for that.

This is my card: CF-WU725B
[MTCD  Android Head Units Q&A] marchnz:
Also in reply to [MENTION=285750]silo[/MENTION]

We can disable the onboard Realtek rtl8723 by shorting r66 to ground (side closest to SOM.) This switches off the "MD725" BT/Wifi chipset allowing the external USB adaptor to function.

Yes, tested :)
[MTCD  Android Head Units Q&A] akispavlopoulos:
Thank you very much for this info! Can you take a photo to show us in detail what to short to the ground? If it is easy...
[MTCD  Android Head Units Q&A] techo91:
Is this going to make the dongle WiFi to work instead of the internal?
[MTCD  Android Head Units Q&A] marchnz:
See attached for JY board. At least on one GS the resistor is hidden below the SOM. Easy enough to remove board and solder wirelink from resistor to ground.

For specifics for which side of resistor see schematic and trace with multimeter.
[MTCD  Android Head Units Q&A] andysabre:
Hi.

Finally the Comfast wu725b arrived (3 month from china to italy... ) but...

IT'S PERFECT!!!

this dongle totally resolved my problem on bt. and the qualiti is more better. I changed the factory settings of the bt in the radio to md725 and all was ok.

I hope this will help someone that have problem with the onboard bt module

Bye
[MTCD  Android Head Units Q&A] silo:
Your'e lucky one, cause your original BT board wasn't using md725 driver. So you can switch MCU board driver to md725, and use external BT/WIFI card with this driver.

But my board originally have md725 and without detaching BT board I will never be able to use external card :/

I wonder if this mod with grounding to resistor is easy enough?
[MTCD  Android Head Units Q&A] marchnz:
It's very easy with basic electronics/soldering skills. Otherwise just desolder the rtl8723 module, it's about 4 solder connections and might be safer :)
[MTCD  Android Head Units Q&A] akispavlopoulos:
One only question has not been answered: Does wifi work from this usb dongle? Or only bluetooth works?
[MTCD  Android Head Units Q&A] RazGame:
So, if i have MD725 in my unit, maybe I can order another USB dongle with another bt module, which supported in MCU ?
[MTCD  Android Head Units Q&A] marchnz:
That's correct. Must hardware disable the onboard rtl8723 first.

---------- Post added at 07:36 AM ---------- Previous post was at 07:35 AM ----------

Both wifi and BT
[MTCD  Android Head Units Q&A] RazGame:
No way to disable internal MD725 by software ?
[MTCD  Android Head Units Q&A] marchnz:
Nope, not that I am aware of. The control 'line' is [WIFI-PWR] controlled by the SOM. There might be a way, assuming that the CPU controls that line, but I wouldn't know without reverse engineering the firmware.
[MTCD  Android Head Units Q&A] silo:
ok, last week I've desoldered rtl8723 board (I've had MD725 BT) and now I can use external USB WIFI/BT ! :)

...but now I'm on Malaysk 8.0 Rom, that have some issues with MD725 anyway, so cannot tell how BT is working :/

I can tell that desoldering was quite simple, I've also used har drier to "unglue" this wifi/bt board from main board.

I've also removed not needed wifi antena.

Anyway, still no BT, and hope Malaysk will fix Oreo soon :)
[MTCD  Android Head Units Q&A] marchnz:
Malaysk does not build from source, all modifications to existing vendor supplied images. This means Bluetooth won't be resolved until HCT include the missing Bluetooth module [sdsdk]. I have the same issue with my headunit in that Bluetooth in Android 6 works OK, Android 8 is a no go due to missing "md725 type 2" [sdsdk].

Hopefully resolved in next HCT update....
[MTCD  Android Head Units Q&A] akispavlopoulos:
What is this "ANT2" in silo's photo of the unit? For what kind of antenna is meant for?
[MTCD  Android Head Units Q&A] silo:
I believe this meant to be BT antena (which was lacking in my Unit!).

I saw on HA post, that there is some antena "glued" to the back of screen.

Ok, so my hope is that we will get this update soon and Malaysk will soon patch his ROM ...
[MTCD  Android Head Units Q&A] yakie996:
Is it possible to use Bluetooth tethering with this bluetooth dongle?
[MTCD  Android Head Units Q&A] sev:
is there any way to add a filter to the audio output to fix this issue on the 725 without having to replace the module?
[MTCD  Android Head Units Q&A] bonfire62:
I doubt it just because the bluetooth is most likely sending a digital audio signal and most the filters from what i gather do analog filtering
[MTCD  Android Head Units Q&A] tabocaw:
I got the comfast wu725b and connected it to my xtrons unit. Changed the bt over to md725 but it never recognizes. no blue light no Bluetooth. The original bt is wq_bc6. the Bluetooth calling is terrible and I'm not sure what I can do now.
[MTCD  Android Head Units Q&A] typos1:
The BC6 is usually ok, so what problem did you have with it ?
[MTCD  Android Head Units Q&A] tabocaw:
crackling over phine calls. Person on the other end not being able to understand me. The only time I use bluetooth is for phone calls and its unusable. I even have a external mic but it's not helping. I'm going to use a piece of tape on the internal mic and see if that makes a difference.
[MTCD  Android Head Units Q&A] typos1:
Or disconnect it, or see if theres an alternative BC6 setting in factory settings (MTCB/C units have this it can improve things), or try grounding the internal or external mic to the head unit chassis, this can also improve things, look at the solutions in the MTCB forum (most of them have BC6s)

Its most likely to be a mic issue, not a BT issue.
[MTCD  Android Head Units Q&A] esziszi:
1. Has anyone tried Bluetooth tethering with this - the phone giving Internet to the head unit, through Bluetooth? This has been asked, but no answers yet. I doubt that it works, since the Android on these units seems to be modded to not include this functionality. Do any of the cooked PX5 ROMs have this? I searched a lot, but haven't found out.

2. Would a similar dongle work, which has external antenna, for better WiFi signal? The chipset is the same, RTL8723BU, but the brand is different. It's a bit more expensive, at 7.99$. It's this one: http://s.aliexpress.com/me2aYrEj.
[MTCD  Android Head Units Q&A] sev:
Wow! Thanks for suggesting this fix, i patiently waited a month for that Comfast 725 to arrive. Plugged it in and nothing, because my unit has a 725 internally. I took it apart and unsoldered the on board one and it worked! music quality seems much better! I can actually stream stuff now!
[MTCD  Android Head Units Q&A] smnrock:
Gone :( I also removed the internal one and now unit doesn't start. It's blowing the fuse immediately when i connect to power supply. Tried new fuses and all blown away the moment powered.

I guess some short-circuit? This is my first experience of desoldering :( . Anything can be done or that's all?
[MTCD  Android Head Units Q&A] warhead19:
I have ordered the Comfast WU725B dongle because my Internal Bluetooth and Wifi stop working... Wifi works fine now with the dongle but bluetooth cant find any device and cant be found by a phone...

Bluetooth is still not working... I have desoldered the original onboard chip and tryed different Firmwares and MCU´s (Hal9k, Malaysk, Original) the led on the dongle is blue but it still not work... I think i give up -.-
[MTCD  Android Head Units Q&A] sev:
Check your solder work, you definitely have a short circuit, the solder pads are very close together, especially on the right side. You need to use a desoldering wick and try to clean up the solder on the pads. Can you send a picture of the board?

---------- Post added at 03:44 PM ---------- Previous post was at 03:42 PM ----------

Strange, im on the original firmware for my hizpo and it works. I'd stick to the original. It also takes a minute or two after the blue light comes on for it to work.
[MTCD  Android Head Units Q&A] warhead19:
Nope... no way to make bluetooth working... The blue light comes on but the device find nothing and cant be found by other devices
[MTCD  Android Head Units Q&A] smnrock:
Here is the pictures
[MTCD  Android Head Units Q&A] smnrock:
Try clearing cache or storage for the Bluetooth app under Apps in Settings and restart once.
[MTCD  Android Head Units Q&A] bjt2:
Damn, I've just tried it myself and have the exact same situation, not sure what to do now as now neither wifi or bluetooth work! I highly recommend NOT removing the bluetooth module!
[MTCD  Android Head Units Q&A] bjt2:
Tried flushing cache, data etc but no effect. The wi-fi kind of works but only before going into sleep. Pretty much screwed the unit now. :crying:
[MTCD  Android Head Units Q&A] techo91:
I was wondering is there any other dongle with a different chipset that we can buy? I installed the Oreo rom of Malaysk and as many other people lost bluetooth (mine has an internal MD725 module and as long as I know Oreo rom is missing the drivers. In this scenario I can't use the dongle nor the integrated one.
[MTCD  Android Head Units Q&A] bjt2:
You would think it should support any of the chipsets under the factory bluetooth list as there should be built in drivers for them?

Since I removed the bluetooth module by unsoldering it, bluetooth and wi-fi no longer worked (with the USB), so I decided to put in my old PX3 board to see if it would come up with that.. total black screen. I then put the PX5 board back in, and now it fully works with USB! How weird is that! Super happy now though..
[MTCD  Android Head Units Q&A] ZeligPC:
I was asking myself exactly the same question. MD725 is keeping me away from Oreo upgrade (I can't take the risk of no bluetooth connection). Unfortunately I've made many searches but nobody seems to specify the chipset of BT dongles, so we have to rely on someone's experience or try a blind purchase hoping to peek the right one... :(
[MTCD  Android Head Units Q&A] marchnz:
A logcat will indicate the md725 type. Search for my posts on the subject.
[MTCD  Android Head Units Q&A] sev:
it appears on the right side, above where it says t-10 you may have a short between the two pads. I'd try cleaning that up and see if it helps.

---------- Post added at 05:42 PM ---------- Previous post was at 05:41 PM ----------

Update on the USB dongle. So it does seem a little better but higher frequencies are still super distorted. Wonder if there's some flaw in the chipset? Maybe a firmware update?

---------- Post added at 06:15 PM ---------- Previous post was at 05:42 PM ----------

I went ahead and hooked up the MD-725 to my PC and tried to stream audio from it. It sounds flawless. I wonder if the issue is in the MTCE MCU mixing audio? This is disappointing.
[MTCD  Android Head Units Q&A] BadAzDB:
My unit doesn’t have a USB input, is there any prayer way I can get a different Bluetooth chip installed? I can never stream music or make phone calls because the quality is horrible.
[MTCD  Android Head Units Q&A] bjt2:
Have you tried the bluetooth echo fix here? I found that it improved sound quality in general very well before I updated to Malaysk.

https://xdaforums.com/android-auto/...neral/px5-solution-bluetooth-echo-v2-t3661284
[MTCD  Android Head Units Q&A] BadAzDB:
Wait this might be a dumb question, but I have the USB cords which let me plug my phone into the unit. Will that suffice? I was thinking it had to have a USB input directly on the unit itself.
[MTCD  Android Head Units Q&A] techo91:
That’s enough and it’s the same as socket on the unit. Try a dongle and test the quality.
[MTCD  Android Head Units Q&A] vitalya_pn:
I changed my MD725 adapter from internal to external but the voice quality is the same. Do not understand what to do tex
[MTCD  Android Head Units Q&A] cascio18:
hi, i bought the md725 module usb dongle and i tried in the car but unsuccessfully. I tried to set the in the factory setting md725, but it doen't work. i also cleared data of bluetooth app, but nothing. And now also the internal module doesn't work. i tried every type of module from the list in factory settings, but bluetooth doesn't return to work. Any suggest?
[MTCD  Android Head Units Q&A] marchnz:
Ive wrote about this extensively.

Take a logcat. If your USB Realtek RTL8723 returns a serial number, it's a type 2 MD725 which BT does not work in Oreo.

I've also asked someone with Oreo and root to make an initial scrip change to force type 2 to use type 1 GOCSDK - so far no takers. I suspect it will work, enabling MD725 on Oreo for all.
[MTCD  Android Head Units Q&A] techo91:
Can you point me to a post with instructions how to do it? I’m currently traveling from work but in a week I can try.
[MTCD  Android Head Units Q&A] cascio18:
I think you are right. I see on logcat the md725 connected, and maybe with a little script that change the bluetooth to type 2 maybe it works. But i don't how to do it:(.
[MTCD  Android Head Units Q&A] alukarulz:
It worked! I first bought the COMFAST RTL8723BU but it would freeze my unit everytime i reboot it. I would have to remove the adapter for it to work as it interfers with the internal md725. So I desoldered the internal Wifi+Bluetooth Module from my unit, so easy to do. (Pictures are in this thread somewhere) and plugged in the adapter which is wifi+bluetooth COMFAST dongle. Worked like a charm. Crisp bluetooth connection and stronger wifi. I’m so happy.
[MTCD  Android Head Units Q&A] sev:
how does your a2dp sound?
[MTCD  Android Head Units Q&A] alukarulz:
sounds about the same. but what changed what phone calls and wifi
[MTCD  Android Head Units Q&A] JonatanP:
it was me, the problem is that it is not possible to install the rom for errors in as signatures, what I do not understand is that both you and ikerg ignore all my messages and mentions.

https://i.imgur.com/VtUK7aV.png
[MTCD  Android Head Units Q&A] marchnz:
Was that from root or modifying image? Root should work.
[MTCD  Android Head Units Q&A] JonatanP:
modifying the image, According to ikerg, it had to be done that way.

I remember that on another occasion I tried modifying the files but I did not get any results, but it was a different modification, previous to the last one you said to make.
[MTCD  Android Head Units Q&A] veriluxxxx:
i am also having wifi issues but no bluetooth issues, should I try the comfast bluetooth adapter or can I use any usb wifi adapter?
[MTCD  Android Head Units Q&A] veriluxxxx:
could someone provide the soldering pictures also, would the microphone still work if the onboard bt/wifi was soldered off?

thanks
[MTCD  Android Head Units Q&A] imran0487:
im just checking if you have found any solution yet for MD725.
[MTCD  Android Head Units Q&A] litoalberto:
Hi, I got it to work.

I have a radio 2 din HXD android 5.1.1

I dismount the module on the board and connect the usb

and I only got the wifi to work

After installing new firmware I have managed to have wifi and bluetooth but I have lost the option DVD and I can not read the CDs but the Bluetooth does work.

I download from this page https://yadi.sk/d/umCvHqCDzHccr/RockChip PX3 Android 5.1/Temp

I install 3188-piko-gaaps-klient-bt-ok.rar

only lost dvd option
[MTCD  Android Head Units Q&A] pir8man:
Does swapping to this USB dongle improve device pairing? Or do you still have the OBD/Phone pairing restriction?
[MTCD  Android Head Units Q&A] veriluxxxx:
[/COLOR]

can you resend the firmware link?
[MTCD  Android Head Units Q&A] imran0487:
Can you give us the link to buy