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Android 10 upgrade - MD725 to RF210 BT module swap

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marchnz

Senior Member
Nov 26, 2012
3,601
719
wombleton
I did receive the module today. Unfortunately the pin descriptions do not fully match to what I can see on my bench unit. My Car unit does not have any pin descriptions on the silkscreen at all.

Code:
Bench Unit Bluetooth Module pin descriptions:

x -BLED
---RST
---SDA
---SCL
---GND
---VDD
---MIC-
---MIC+
---SGND
---LOUT
---ROUT
x--PIO10

The first and last pin do not seem to be connected.

And here the pin descriptions on Aliexpress module.

Code:
Aliexpress module pin descriptions:

---RST
---RX
---TX
---GND
---5V
---AGND
---NC
---GND
---CTS
---RTS

Basically the first pins (RST, SDA/SCL/GND/5V) might match but the second part of my bench unit WQ_BC5 seems to be some audio interface (MIC-, MIC+, SGND, LOUT, ROUT) while the Aliexpress module provides some potential serial interface (GNC, CTS, RTS).

I guess I will have to check some schmatics before. Perhaps my car unit is wired differently too.

Looks odd, I wonder if it's an error in printing on the board. AGND is usually audio ground, but I don't see any [mic] or L, R.
 

switchboy

Member
Dec 2, 2010
34
18
I don't think this aproach is going to work since our boards are specificly designed to use the MD725. The MD725 uses USB to communicate and is solderd to an antenna at the other end. There would not be a need for manufacturers to also outfit the board for the connection type used by other WiFi/BT modules.

Our best shot might be to find another compatible USB WiFi/BT module which will probably have a completly different pinlayout compared to the MD725. But if we know the layout of the MD725 we could just run wires from the pads on our boards to the corresponding pads on whichever compatible WiFi/BT module we find. It won't look pretty, but in theory it should work.

The hardest part is finding a compatible USB WiFi/BT dongle. And if we have that we might save ourselves the soldering hassle and just use a USB splitter cable and extension cable and place the dongle somewere high behind the dash where te reception will be a hundred times better then from the SHARED WiFi/BT antenna which is located behind the headunit.

Just as a side note has anyone who has a MD725 version 1 tried to just replace /system/bin/gocsdk (be sure to give it 755 permission!) with one from android 9? It did not work for the MD725 version 2 in android 6 back in the day due to the fact that static linking was used so the binairy would not excecute. But the changes in architecture from 9 > 10 are much smaller so in theory this might just work. It did for SD-968 on android 9 by replacing /system/bin/sdsdk968 Maybe no one tried this aproach for MD725v1 because we failed with the MD725v2 in the android 8 days

https://nextcloud.gamesdust.nl/s/L3JnpqDzzr6tPfo the android 9 bin. but it is bit identical to the android 10 bin so something else is wrong.

init.hct.rc are both the same so that is not the problem either
 
Last edited:

marchnz

Senior Member
Nov 26, 2012
3,601
719
wombleton
I don't think this aproach is going to work since our boards are specificly designed to use the MD725. The MD725 uses USB to communicate and is solderd to an antenna at the other end. There would not be a need for manufacturers to also outfit the board for the connection type used by other WiFi/BT modules.

Our best shot might be to find another compatible USB WiFi/BT module which will probably have a completly different pinlayout compared to the MD725. But if we know the layout of the MD725 we could just run wires from the pads on our boards to the corresponding pads on whichever compatible WiFi/BT module we find. It won't look pretty, but in theory it should work.

The hardest part is finding a compatible USB WiFi/BT dongle. And if we have that we might save ourselves the soldering hassle and just use a USB splitter cable and extension cable and place the dongle somewere high behind the dash where te reception will be a hundred times better then from the SHARED WiFi/BT antenna which is located behind the headunit.

Just as a side note has anyone who has a MD725 version 1 tried to just replace /system/bin/gocsdk (be sure to give it 755 permission!) with one from android 9? It did not work for the MD725 version 2 in android 6 back in the day due to the fact that static linking was used so the binairy would not excecute. But the changes in architecture from 9 > 10 are much smaller so in theory this might just work. It did for SD-968 on android 9 by replacing /system/bin/sdsdk968 Maybe no one tried this aproach for MD725v1 because we failed with the MD725v2 in the android 8 days

I believe your assumption is incorrect.

Units with MD725 combined wifi/bt often do include provision for other BT module, which use serial comms. Mine does, and the others I have see do too, including the GS board I have and HA units I've seen posted here.

No need to replace the MD725 if changing BT. The MD725 for WIFI and the separate BT module is then used. This is how it works - check the schematic if unsure.

For those without the PCB pads, this suggested BT module could be wired in by identifying the relevant connections from the schematic.

I've suggested a source for the module, over to others to give it a go.

Regarding changing the vendor binary for md725, yes a few have tried from Android 6 to 8 and it doesn't work. You could try the Android 9 one, might be worth a shot. Regarding static linking, can you explain more?
Good thoughts. Id say give it a go :)
 
Last edited:

switchboy

Member
Dec 2, 2010
34
18
I don't think this aproach is going to work since our boards are specificly designed to use the MD725. The MD725 uses USB to communicate and is solderd to an antenna at the other end. There would not be a need for manufacturers to also outfit the board for the connection type used by other WiFi/BT modules.

Our best shot might be to find another compatible USB WiFi/BT module which will probably have a completly different pinlayout compared to the MD725. But if we know the layout of the MD725 we could just run wires from the pads on our boards to the corresponding pads on whichever compatible WiFi/BT module we find. It won't look pretty, but in theory it should work.

The hardest part is finding a compatible USB WiFi/BT dongle. And if we have that we might save ourselves the soldering hassle and just use a USB splitter cable and extension cable and place the dongle somewere high behind the dash where te reception will be a hundred times better then from the SHARED WiFi/BT antenna which is located behind the headunit.

Just as a side note has anyone who has a MD725 version 1 tried to just replace /system/bin/gocsdk (be sure to give it 755 permission!) with one from android 9? It did not work for the MD725 version 2 in android 6 back in the day due to the fact that static linking was used so the binairy would not excecute. But the changes in architecture from 9 > 10 are much smaller so in theory this might just work. It did for SD-968 on android 9 by replacing /system/bin/sdsdk968 Maybe no one tried this aproach for MD725v1 because we failed with the MD725v2 in the android 8 days

https://nextcloud.gamesdust.nl/s/L3JnpqDzzr6tPfo the android 9 bin. but it is bit identical to the android 10 bin so something else is wrong.

init.hct.rc are both the same so that is not the problem either
Checked the libraries on android 9 and 10 that gocsdk is depended on and they are different. So where probably changed and broke our driver. Swapping them with android 9 libs might mess up other stuff and require a reflash of the current firmware to fix it. Or it might magicly work haven't tested it since I own a MD725V2 which is certainly not going to work.

I don't have any soldering skills yet, planning to change that in the near future. One of my projects is going to be finaly changeing my type 2 to type 1.
 

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switchboy

Member
Dec 2, 2010
34
18
As far as just soldering on a BC6 i apear to be SOL.

I might as well look for a different MTCD/E mainboard without PX(30 5 or 6) but i havent got any luck finding one on ali express. If anyone has a broken radio with working mainboard I am interested at this point


IMG_0882.png
IMG_0884.png



Edit:
So, I ripped off the pads while desoldering the MD725 module. I can hotwire the ground and 3.3v but I could not trace the two datalines so can't hotwire those sadly. Tried to use the MD725 v1 as a USB device. That worked for 10 minutes but in the end the chip decided that it did not like the 5V input after all and shorted.

Considering my options:
- Order another MD725v1 and solder in a voltage divider to drop the USB 5v to 3.3v and hope this ghetto solution is stable and then try to fix the software problem or otherwise be stuck on android 9 until google app makers drop support (which is going to happen before the end of the car's lifetime)

- Get my hands on another motherboard and hope/pray my screen and custom front with buttons can be transplanted. If I can source a unit with a broken screen or broken PX5 then is is probably the cheapest option but it is difficult and time consuming to source the parts since I can't seem to find the motherboard as a stand alone on AliExpress and dirt cheap broken units are not common on local second hand market sites in my area. (and as a rule lack a good description of the internal hardware)

- Upgrade to a PX6 unit and enjoy faster boot times, better radiochip and better amplifier. These units are still dirt cheap anyways and I found one shipping from within the EU. It is nice not to pay extra import taxes and have acces to warrenty

I chose the last option since the car in which this headunit resides is my daily driver and I don’t have a lot of free time to fiddle around right now. So don’t expect any more updates regarding a software fix from me any time soon. I might make a USB MD725v1 just for fun and giggles but not any time soon. (It takes at least 20-30 days for a replacement chip to be shipped from China)


IMG_20210421_165456.png


IMG_20210425_235528.png


Important lessons learned:

- Don't attempt SMD (de)soldering without a heatgun!
Even with my biggest soldertip and a copper wire wrapped around the soldered on PCB I just could not get all the solder points hot enough at the same time.
- Double check the input voltage on a board before assuming USB is USB so it is got to be 5v!
 
Last edited:

SkyBeam2048

Senior Member
Jan 25, 2011
208
93
Lucerne
I did receive the module today. Unfortunately the pin descriptions do not fully match to what I can see on my bench unit. My Car unit does not have any pin descriptions on the silkscreen at all.

Code:
Bench Unit Bluetooth Module pin descriptions:

x -BLED
---RST
---SDA
---SCL
---GND
---VDD
---MIC-
---MIC+
---SGND
---LOUT
---ROUT
x--PIO10

The first and last pin do not seem to be connected.

And here the pin descriptions on Aliexpress module.

Code:
Aliexpress module pin descriptions:

---RST
---RX
---TX
---GND
---5V
---AGND
---NC
---GND
---CTS
---RTS

I did a bit more checking on my bench unit and used a scope on the L/R out pins and they do actually carry analog audio signals and seem to be wired up somewhere to the BD3702 chip.
So a direct swap of the modules won't work (at least assuming the Aliexpress module uses digital interfaces as indicated by silk-screening).
I don't know yet if I could somehow connect the BT module differently to the MCU or SOM and where.
 
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marchnz

Senior Member
Nov 26, 2012
3,601
719
wombleton
As far as just soldering on a BC6 i apear to be SOL.

I might as well look for a different MTCD/E mainboard without PX(30 5 or 6) but i havent got any luck finding one on ali express. If anyone has a broken radio with working mainboard I am interested at this point


View attachment 5278947View attachment 5278949


Edit:
So, I ripped off the pads while desoldering the MD725 module. I can hotwire the ground and 3.3v but I could not trace the two datalines so can't hotwire those sadly. Tried to use the MD725 v1 as a USB device. That worked for 10 minutes but in the end the chip decided that it did not like the 5V input after all and shorted.

Considering my options:
- Order another MD725v1 and solder in a voltage divider to drop the USB 5v to 3.3v and hope this ghetto solution is stable and then try to fix the software problem or otherwise be stuck on android 9 until google app makers drop support (which is going to happen before the end of the car's lifetime)

- Get my hands on another motherboard and hope/pray my screen and custom front with buttons can be transplanted. If I can source a unit with a broken screen or broken PX5 then is is probably the cheapest option but it is difficult and time consuming to source the parts since I can't seem to find the motherboard as a stand alone on AliExpress and dirt cheap broken units are not common on local second hand market sites in my area. (and as a rule lack a good description of the internal hardware)

- Upgrade to a PX6 unit and enjoy faster boot times, better radiochip and better amplifier. These units are still dirt cheap anyways and I found one shipping from within the EU. It is nice not to pay extra import taxes and have acces to warrenty

I chose the last option since the car in which this headunit resides is my daily driver and I don’t have a lot of free time to fiddle around right now. So don’t expect any more updates regarding a software fix from me any time soon. I might make a USB MD725v1 just for fun and giggles but not any time soon. (It takes at least 20-30 days for a replacement chip to be shipped from China)


View attachment 5291129

View attachment 5291131

Important lessons learned:

- Don't attempt SMD (de)soldering without a heatgun!
Even with my biggest soldertip and a copper wire wrapped around the soldered on PCB I just could not get all the solder points hot enough at the same time.
- Double check the input voltage on a board before assuming USB is USB so it is got to be 5v!

Sorry to hear about your damaged board. I didn't have the same experience in damaging the board using good old desolder wick, I desoldered and carefully raised with a needle.

@Aaaron16 has kindly offered a unit that I can test on and aim to create a write up on. Very much appreciated @Aaaron16

It doesn't appear you have some of the BT module pads/options for the likes of a bc6 which could be reused, which would make the process more difficult.
 

SkyBeam2048

Senior Member
Jan 25, 2011
208
93
Lucerne
I don't know yet if I could somehow connect the BT module differently to the MCU or SOM and where.
I did have a look at some schematics and found the witson schematics which show a mic-switch and in the "mic_sel" circuit it shows the 10-Pin Connector presumably. This connector seems to be equipped with audio L/R and mic+/mic- connected to a switching circuit (74LVC1G3157GW) actuated by MIC-EN pin on MCU.
My RF210 module does not have any analog input/output but the 10-pin "MIC_SEL" connector seems also to use RX/TX pins connected to BT-RX/BT-TX on pin 27 (RX)/26(TX) on the SOM connector.
I didn't find any RTS/CTS pins but technically they are not strictly required and could be pulled to GND.

So there might be a chance to wire up the RF210 directly to the SOM. But I am not fully sure if I would perhaps get Serial/BT connection but it might fail to get mic audio during calls. However I noticed that the "MICIN+" connector on the mic switch might switch the microphone between SOM and the bluetooth 10-pin header. So either pulling the selector pin high or low might forward the mic input to pin 11 of the SOM connector. Technically allowing Android to process audio and forward it to the BT module.

Well, there is quite a lot of guessworking involved. So basically I would ignore RTS/CTS and just use RX/TX directly connected to the SOM and wire up 3.3 and 5V supplies to the module.

If I find the time to test it I will perhaps try it. However I guess this is not a mod we would be able to recommend to anybody as it's not a simple plug-in replacement. Some boards out there might have an unequipped 10-pin connector but one would have to individually check if it corresponds to analog-wired module (my bench unit claims to use WQ_BC5) or digital serial RF210 style interface. They are not easily interchangeable.
 
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SkyBeam2048

Senior Member
Jan 25, 2011
208
93
Lucerne
Well, there is quite a lot of guessworking involved. So basically I would ignore RTS/CTS and just use RX/TX directly connected to the SOM and wire up 3.3 and 5V supplies to the module.
I was too curious and decided to do some soldering today on my bench unit with witson 10-pin connector:
  • Desoldered WQ_BC5 module from main board
  • Soldered in a socket for easy swap
  • Tested that the SDA/SCL pins of the WQ_BC5 module are actually linked to Pin 27/26 on SOM (BT_RX/BT_TX)
  • Soldered a connector just using RX, TX, 5V and GND to RF210 module, ignoring all other (analog audio/mic connectors)
  • Went into factory defaults and switched BT module type to WQ_RF210, restarted unit
I was pretty surprised that I could immediately pair my phone to the head unit without any problems. I also was able to use the A2DP app to play audio from the phone on my MTCE device with no problems at all.

Now the downsides: I was actually able to start and accept phone calls but no audio during calls on speakers and no mic audio transmitted to the caller on the other end either.
Perhaps the MIC output could be resolved with changes on the mentioned MIC switch IC to switch the MIC input to android system rather than putting it onto the pin going to the Bluetooth module (not connected). However I don't know about the speaker output. Speaker output from the phone should somehow be decoded by Android now (transmitted digitally on serial interface to SOM). And I do not have any clue yet how I can achieve this. Perhaps my device is also somehow muting Android audio output during calls as with the stock module the audio was mixed directly at the BD3702 chip. So I would need to find a way for my headunit to decode and play audio supplied via serial interface.

At least I believe I could use the RF210 module on my car unit; worst case soldering it directly to BT_RX/BT_TX of the SOM which would enable A2DP.
Also MD725 is a combined WiFi/Bluetooth module. So I guess here audio is already transferred using a serial or USB interface, so I might not hit the same problem about audio routing but I might run into problems having 2 Bluetooth modules in the system, one on USB and one on serial attached to SOM - but this might not be a problem on Android 10 where MD725 Bluetooth is not supported anyway.
 

marchnz

Senior Member
Nov 26, 2012
3,601
719
wombleton
I was too curious and decided to do some soldering today on my bench unit with witson 10-pin connector:
  • Desoldered WQ_BC5 module from main board
  • Soldered in a socket for easy swap
  • Tested that the SDA/SCL pins of the WQ_BC5 module are actually linked to Pin 27/26 on SOM (BT_RX/BT_TX)
  • Soldered a connector just using RX, TX, 5V and GND to RF210 module, ignoring all other (analog audio/mic connectors)
  • Went into factory defaults and switched BT module type to WQ_RF210, restarted unit
I was pretty surprised that I could immediately pair my phone to the head unit without any problems. I also was able to use the A2DP app to play audio from the phone on my MTCE device with no problems at all.

Now the downsides: I was actually able to start and accept phone calls but no audio during calls on speakers and no mic audio transmitted to the caller on the other end either.
Perhaps the MIC output could be resolved with changes on the mentioned MIC switch IC to switch the MIC input to android system rather than putting it onto the pin going to the Bluetooth module (not connected). However I don't know about the speaker output. Speaker output from the phone should somehow be decoded by Android now (transmitted digitally on serial interface to SOM). And I do not have any clue yet how I can achieve this. Perhaps my device is also somehow muting Android audio output during calls as with the stock module the audio was mixed directly at the BD3702 chip. So I would need to find a way for my headunit to decode and play audio supplied via serial interface.

At least I believe I could use the RF210 module on my car unit; worst case soldering it directly to BT_RX/BT_TX of the SOM which would enable A2DP.
Also MD725 is a combined WiFi/Bluetooth module. So I guess here audio is already transferred using a serial or USB interface, so I might not hit the same problem about audio routing but I might run into problems having 2 Bluetooth modules in the system, one on USB and one on serial attached to SOM - but this might not be a problem on Android 10 where MD725 Bluetooth is not supported anyway.

Great work.

There is no need for the removal of the MD725, as you found, BT would continue to provide wifi.

Also as you found, BT selection is done via MCU/factory settings, selecting RF210.

I believe the last issues with BT mic and call audio is solvable. A later version schematic with this BT module would be helpful to see if there might be board level changes.

Very well done giving it a go, you're helping to develop a solution!
 
Last edited:

SkyBeam2048

Senior Member
Jan 25, 2011
208
93
Lucerne
Also note that the WQ_BC6 module is available for sale on Aliexpress too. So people which do have the 10-Pin "witson style" header with analog input/output might be able to add this module to the unpopulated header.

So before ordering it might be required to clarify which module type might fit. Worst case is that none of them will fit also due to other unpopulated components on the main board.

However the WQ_RF10 module might be more easy to wire directly to the SOM as it requires only a serial RX/TX interface as well as 5V and GND.
 

abdelmonem

Member
Jan 26, 2009
45
5
Hello all

I'm switching from md-705 to RF 210, look at the picture below without problems, just for info, different printing on the board doesn't mean all BTs are using the same protocol when switching in factory setting, that will reconfigure all bin
 

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marchnz

Senior Member
Nov 26, 2012
3,601
719
wombleton
Hello all

I'm switching from md-705 to RF 210, look at the picture below without problems, just for info, different printing on the board doesn't mean all BTs are using the same protocol when switching in factory setting, that will reconfigure all bin

I dont quite follow. Bluetooth module Pins are labelled differently between the two types.

Are you saying a direct swap worked for you or not?
 

abdelmonem

Member
Jan 26, 2009
45
5
I dont quite follow. Bluetooth module Pins are labelled differently between the two types.

Are you saying a direct swap worked for you or not?
yes exactly don’t care about what’s labelled in this board because it’s different hardware between Bluetooth 4.2 and 5 when you change in factory settings it will read new board , as you see I contact directly I didn’t change any bin

and also I test mic and BT audio and I was have problem fo internet via BT with old one ,now it’s solved, all functions working perfect

only 4 bin most by matching RX ,TX, GIND, 5.v or 3.3v or VDD or ACC all are same
if you want use it with usb for test also you will use this 4bin ,look in picture below
 

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[email protected]

Senior Member
Apr 9, 2017
87
10
Wrocław
4.2, które zostały wykonane, na tej wystawie, ponieważ były obecne urządzenia, 5 po zmianie ustawień próbnych, próbnych testów, jak również Bluetooth nie jest już istniejącym binu

a także testuję mikrofon i dźwięk BT i ma problem z internetem przez BT ze starym, teraz jest rozwiązany, wszystkie kluby z zespołu

tylko 4 pojemniki najbardziej pasujące do RX, TX, GIND, 5.v lub 3.3v lub VDD lub ACC są takie to samo
Jeśli chcesz go z usb do testu, poniżej tego 4bin, spójrz na zdjęcie!

Czy ten BT da się zamontować w tym miejscu na tej płycie GS?
 

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abdelmonem

Member
Jan 26, 2009
45
5
if any one need FC6000TN i can help ,chines seller thy not sell it separate but i can help for that also all version are compatible to most all mcu

already i made order when i get it i'll post here feedback about
 

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  • 1
    BT is already installed and works great on "HCT4_px5_10.0_ota (20201216)"
    1
    As in post # 39, and my album is post # 35 without BT yet
    1
    Hello everyone

    just now I finished test all bluetooth module available in Chinese market AliExpress or alibaba or other’s the best module is RF-210 test in 3 Different mcu working very good don’t try other modules you’ll loos your time
    just one thing for future I attached bin connector to motherboard after that attach the module I didn’t solder direct to main board

    all test with 10 or 9 bin in motherboard
    For 12 bin I didn’t trying because I don’t have it but still you can send me picture of your main board and BT module I’ll try to find out

    best regards
  • 1
    For users with MD725 Blue wanting to upgrade to Android 10, a potential BT module swap may now be possible. A supplier found here:

    For now, I won't be "upgrading", staying with the last free version 3.1 of Hal Android 8, as all the integrations work.
    1
    I am not fully sure if this will always fit. I got a KLD unit and it uses MD725. The MD725 modules are integrated Bluetooth/WiFi module. The module actually is sitting on a soldered-on board which got 4 pins on one and 3 pins on the other side. Similar to this one. The one in the link seems to have only 1 RF out while my MD725 seems to have 2 antenna connectors. Might weell be that one is for BT and one for Wifi and the one on Ali is WiFi only.

    Picture of my board here.

    However I had a look at pictures I took from the KLD board. On the edge of the board where the ST MCU sits (behind the FM can) I see a pinheader with 11 solder points which is unequipped. Also the surrounding passive components seem to be all equipped. The module you refer to seem to have a 10-Pin interface.

    I do have another unit with WQ_BC5 bluetooth (which also works on Android 10) where a very similar pinheader is equipped with a Bluetooth module. The module however does not look identical to the one you linked but it might work. Also on this board the 11-Pin header is used while the first pin (which is "crossed" by silkscreen) is not used.

    A couple of things are not fully clear to me:
    • I guess nobody will know if the pinheader is actually connected to the MCU unless it's equipped.
    • Any clue what type the module is? The chip looks like Realtek RTL8761___ which might be an RTL8761ATV. As I see it's got an UART interface it might be pretty standard.
    • Will the module eventually conflict with the built-in BT module in MD725? Likely not as I guess the USB-connected bluetooth part of MD725 will simply not be used if another BT module is selected in factory settings.
    I might end up just ordering one and solder it to my board and then having to try all BT modules in factory settings in order to find the matching one.
    1
    Yes, the header is correct, unless the header is for DTV like my unit.

    I have no clue how this would look like.

    what I would do is wire according to the schematic. Probably easier said than done, but doable.

    Well, I guess there is no schematic included in the ali offering. Neither for my unit. So I will likely have to follow some traces. Or just solder it and watch out for some magic smoke.

    However I believe the pinout is likely always the same on those units. Same as for those USB daughterboard modules (see my other link). However here at least the boards are usually labelling the pins.

    I actually ordered one of these modules and will have a look. Perhaps soldering it into my bench unit first (replacing the WQ_BC5 module). If no magic smoke escapes I can search for the correct module type in factory settings and then solder it to my car unit.

    Well, to be honest I am quite OK currently with HAL Android 9 on my car unit so I will see when I got time to try this.
    1
    I actually ordered one of these modules and will have a look. Perhaps soldering it into my bench unit first (replacing the WQ_BC5 module). If no magic smoke escapes I can search for the correct module type in factory settings and then solder it to my car unit.

    I did receive the module today. Unfortunately the pin descriptions do not fully match to what I can see on my bench unit. My Car unit does not have any pin descriptions on the silkscreen at all.

    Code:
    Bench Unit Bluetooth Module pin descriptions:
    
    x -BLED
    ---RST
    ---SDA
    ---SCL
    ---GND
    ---VDD
    ---MIC-
    ---MIC+
    ---SGND
    ---LOUT
    ---ROUT
    x--PIO10

    The first and last pin do not seem to be connected.

    And here the pin descriptions on Aliexpress module.

    Code:
    Aliexpress module pin descriptions:
    
    ---RST
    ---RX
    ---TX
    ---GND
    ---5V
    ---AGND
    ---NC
    ---GND
    ---CTS
    ---RTS

    Basically the first pins (RST, SDA/SCL/GND/5V) might match but the second part of my bench unit WQ_BC5 seems to be some audio interface (MIC-, MIC+, SGND, LOUT, ROUT) while the Aliexpress module provides some potential serial interface (GNC, CTS, RTS).

    I guess I will have to check some schmatics before. Perhaps my car unit is wired differently too.
    1
    I don't think this aproach is going to work since our boards are specificly designed to use the MD725. The MD725 uses USB to communicate and is solderd to an antenna at the other end. There would not be a need for manufacturers to also outfit the board for the connection type used by other WiFi/BT modules.

    Our best shot might be to find another compatible USB WiFi/BT module which will probably have a completly different pinlayout compared to the MD725. But if we know the layout of the MD725 we could just run wires from the pads on our boards to the corresponding pads on whichever compatible WiFi/BT module we find. It won't look pretty, but in theory it should work.

    The hardest part is finding a compatible USB WiFi/BT dongle. And if we have that we might save ourselves the soldering hassle and just use a USB splitter cable and extension cable and place the dongle somewere high behind the dash where te reception will be a hundred times better then from the SHARED WiFi/BT antenna which is located behind the headunit.

    Just as a side note has anyone who has a MD725 version 1 tried to just replace /system/bin/gocsdk (be sure to give it 755 permission!) with one from android 9? It did not work for the MD725 version 2 in android 6 back in the day due to the fact that static linking was used so the binairy would not excecute. But the changes in architecture from 9 > 10 are much smaller so in theory this might just work. It did for SD-968 on android 9 by replacing /system/bin/sdsdk968 Maybe no one tried this aproach for MD725v1 because we failed with the MD725v2 in the android 8 days

    https://nextcloud.gamesdust.nl/s/L3JnpqDzzr6tPfo the android 9 bin. but it is bit identical to the android 10 bin so something else is wrong.

    init.hct.rc are both the same so that is not the problem either
    Checked the libraries on android 9 and 10 that gocsdk is depended on and they are different. So where probably changed and broke our driver. Swapping them with android 9 libs might mess up other stuff and require a reflash of the current firmware to fix it. Or it might magicly work haven't tested it since I own a MD725V2 which is certainly not going to work.

    I don't have any soldering skills yet, planning to change that in the near future. One of my projects is going to be finaly changeing my type 2 to type 1.