ISUDAR Head Unit, USB DAC and Volume Control - MTCD Android Head Units Q&A

Hello,
I have an ISUDAR Head Unit (NA03A7UN0708) with Android 7.1.1
I have been trying to get my USB DAC (Behringer UCA202) to work for a while which I have used on all of my other android devices and recently managed to flash my ISUDAR with a modified Rom and it is now rooted.
My dac did not work initially, I had added the usb_audio_policy_configuration.xml (not sure if this was required but seemed to be missing) and also made changes in the developer settings changing the usb type to "Audio Source"
The dac now works and switches perfectly when plugged in, however I cannot control the volume, it is just fixed at full volume.
Any ideas on how I can make the system volume work with my usb dac?
Thanks in advanced

Im trying to do the same!! I was thinking of building something with ardiuno chip and use that to control android system volume with a dash rotary or steering wheel controls. The only issue with this is that u wont get radio or bluetooth calling through the usb dac...

Related

Emulate an Iphone USB interface to a car radio?

I recently purchased a car that has a USB interface for the radio. My wife's Iphone fully integrates with it, of course, and via the radio's interface but the Samsung only mounts as a connected drive.
I have read other thread where people were able to force their Samsung into car dock mode by modifying a USB cable. Is there anyway to just do that in software?
you misunderstand what car mode is.
Good luck! I switched back to my iPhone for this reason alone. I listen to a lot of podcasts and I couldn't get this to work via the USB interface and I don't have bluetooth on my head unit. I can't seem to get the newest update to see if that works either. Would love to know if someone has a solution that doesn't require making your own cable.
yo sleze..what model car if i may ask?
i made my own auxiliary input for my car(i know its not a big feat) with an old dsl filter a soldering gun and some resistors and capacitors.. i might be interested in creating a usb interface for my car and then maybe i can give you some insight .. big maybe
well you will never get the headunit to command the phone, android simply doesn't support anything like that. but you can get audio over USB which is triggered by shorting a couple pins through a resistor. ill have to look up that thread but there may already be a dongle or cable out there to do this. it may not be say "android carmode" but if you find the name of the USB standard that they use to trigger it you can find the appropriate cable or dongle.
isnt there a usb headset available that can stop/start music and next track functionality ..if so you could (in theory) make a usb interface that would allow the head unit or in my case steering wheel control to work similarly?
no it wont command the phone. the framework and apps don't have an interface for that. plus the headunit would need special drivers if the phone had that capability. the issue with android is too many manufacturers do things different so unless google comes out with that on a nexus and tells maunfacturers the way it needs to be implimented I don't see any hope.
there might be a way to echo the commands through adb if you have a computer in your car. but I guess you'd have to know how the music app works for that.
we All know apple has the accessories market down pretty good. even though some older accessories don't work with the newest hardware. that's the one thing apple is good for, a wide accessory market.
now if you have a Bluetooth controler and it uses the right protocol to work with thw samaung bluetooth stack then you might be able to map keys to certain functions with an app or simple configuration file editing. but as far as USB goes I don't think android is designed to host USB input devices. there is limited otg usb support on certain special galaxy s and nexus 1 and nexus s kernels but nothing native.
maybe some 3rd party root app could eventually be developed but I haven't heard of one yet.
besides all that, who knows if the head unit will know to go into audio over USB mode in the first place, even if you get the phone in that mode, will the headunit be looking for USB storage and an iPhone interface only? was it designed to accept USB audio other than an iPod interface?
well with my car BMW mad a usb interface for ipod/iphone.. i hate mac so scratch that.. i also have a usb interface(i can control radio/nav functions via carputer) that is designed to work with I-BUS (intelligent input bus) which is what some BMW's used for audio/nav integration. some newer models actually come with a usb input that was designed to work with most media players..so i thought maybe with some time/frustration/rum..i might be able to make it work..
mejori said:
well with my car BMW mad a usb interface for ipod/iphone.. i hate mac so scratch that.. i also have a usb interface(i can control radio/nav functions via carputer) that is designed to work with I-BUS (intelligent input bus) which is what some BMW's used for audio/nav integration. some newer models actually come with a usb input that was designed to work with most media players..so i thought maybe with some time/frustration/rum..i might be able to make it work..
Click to expand...
Click to collapse
It still to my understanding that on BMW iDrive system will have full integration with iOS. We had a 2010 5 series at home with all the bell and whistles on it, and even then it would only display song names. With my iPod we got full library options, podcast too. Android will only be able to be used as a mounted devices.
Sent from my SAMSUNG-SGH-I997 using xda premium
I used to have an iPhone and installed this kit http://usaspec.com/product.php?ProductID=18. After switching to android I just use a 2.5mm to RCA cable to plug in to the same unit. Not worried too much about integrating with car controls - I also use a phone mount. Does your head unit have any AUX IN connectivity? Maybe on the rear? If so just play audio through the headphone jack. There's always the lighter socket RF adapter option too, but audio quality with those things can be lame.
Samsung-SGH-I997 Infused 2.3.3
yeah the headphone amp on the infuse has pretty good fidelity too. the headphone Jack might not be as convenient as a single USB that also charges the phone but I'd you want to use the playlists and 3rd party apps like Pandora or Google music its the best way. audio over USB needs the dock or special cable to trigger but I don't know which headunits will support that.

PX5 USB Audio problems & finds discussion thread

I know that a lot of people here likes good sound quality and want to use USB DAC on their head unit.
So I started this thread so maybe someone can come up with a solution to get rid of our USB Audio problems. :good:
First of all, I have 3 different USB audio interfaces I tried on my MTCD PX5 head unit. I use these for SPDIF Coaxial output, so I can send a clean digital signal to my DSP (MiniDSP 6X8) spdif input.
My USB audio devices:
PCM2704 (Worst sound quality of the 3, but still good)
CM6631A (Nice sound quality)
SMSL x-usb (XMOS chip) (Excellent, best sound quality of my adapters)
Here is my findings for each model so far:
PCM2704 - With native Android USB Audio driver (MTCD Music player, Spotify, Google Music, etc) : Plays without any pops&clicks noises 44khz, 48Khz, 96Khz files (Thats good).. BUT only in MONO, so no stereo ! (That sucks.)
PCM2704 - With custom USB Audio driver (Usb Audio Player Pro, Neutron, Hibby, Onkyo apps) : Plays perfectly 44khz audio files but CANNOT play 48khz or 96khz audio files, there is no sound. at all :crying:
CM6631A - With native Android USB Audio driver (MTCD Music player, Spotify, Google Music, etc) : Lots of pops&clicks noises, cannot listen to this.. BUT output in stereo, plays 44khz/48khz/96khz files.
CM6631A - With custom USB Audio driver (Usb Audio Player Pro, Neutron, Hibby, Onkyo apps) : Lots of pops&clicks noises, cannot listen to this.. Output in stereo, plays 44khz/48khz/96khz.
SMSL X-USB Xmos - With native Android USB Audio driver (MTCD Music player, Spotify, Google Music, etc) : Lots of pops&clicks noises, cannot listen to this.. BUT output in stereo, plays 44khz/48khz/96khz files.
SMSL X-USB Xmos - With custom USB Audio driver (Usb Audio Player Pro, Neutron, Hibby, Onkyo apps) : Lots of pops&clicks noises, cannot listen to this.. Output in stereo, plays 44khz/48khz/96khz.
Good to know:
PCM2704 is USB 1.1 full speed device, isosynchronous.
CM6631A is USB 2.0 fullspeed/high speed device, asynchronous.
SMSL X-usb Xmos is USB 2.0 fullspeed/high speed device, asynchronous.
Also good to know: Android Marshmallow 6 Mono output USB Audio problem is a well known problem across multiple Android devices (Cellphones, tablets, etc.) So lets assume the mono output on the PCM2704 is "normal". What is not normal with the PCM2704 is that it can only play 44khz audio, no 48khz.
First question that comes to my mind: Does the PX5 USB drivers/kernel has a problem with USB2.0 ?
Another question: Does our PX5 firmware mess with the sample frequency (44khz, 48khz, etc) ?
Thanks for any useful comment !
I can't believe I'm the only one here using a USB DAC on a PX5..?
I also interested
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---------- Post added at 01:17 PM ---------- Previous post was at 01:15 PM ----------
How to get the px5 use usb as digital out? I tried cyrus soundkey but no sound
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excellent thread, I was just trying to search on this very thing. My guess that using this as audio output it does not pass the radio or AVIN through it does it? since the MCU is separate from android
I have heard (but not tested first hand) that these will play stereo on 6.0.1
HiFimeDIY Sabre 2016
SA9227 + PCM5102A ( on eBay, http://www.ebay.com/itm/182289773453?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT)
M2Tech HiFace DAC
FiiO Q1
-=Jeff=- said:
excellent thread, I was just trying to search on this very thing. My guess that using this as audio output it does not pass the radio or AVIN through it does it? since the MCU is separate from android
I have heard (but not tested first hand) that these will play stereo on 6.0.1
HiFimeDIY Sabre 2016
SA9227 + PCM5102A ( on eBay, http://www.ebay.com/itm/182289773453?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT)
M2Tech HiFace DAC
FiiO Q1
Click to expand...
Click to collapse
If I test my 3 USB audio devices with USB Audio Player Pro, they all work great on my Android 6 Lenovo Tablet, Nexus 6P cellphone (Android 7/ Android 8 Beta), and worked perfectly on my previous PX3 (RK3188) (Android 5.1) Head unit.
So I dont think it's a compatbility problem with the Android version, it's more of a software/kernel issue, the way the audio is handled with the PX5.
I tried changing some settings in audio_policy.cfg but I did not manage to stop the pops/clicks from happening.
Hi,
I am also very interested in using USB Audio on a PX5.
I have an EONON GA7150A 32GB BMW unit.
MCU is "MTCD_WWW_V2.54b_2", Build is "px5-userdebug 6.0.1 MXC89l user.hct.20170617.171922 test-keys"
I run a car audio / performance / engineering company. We're doing a SQ install on a 04 BMW M3 with all Audison Prima gear going to an Audison Bit 8.9 amp/processor.
I got a Behringer UCA-222 hoping to use it - plugging it into my tablet (Samsung Tab S 8.4") - it works perfectly without any configuration, so I had hoped it'd work with the Android HU as well.
Plugging it into the Android HU - it DOES work - I can play audio from any apps (YouTube, Google Voice Search both output to the USB device) - I have installed SoundAbout Pro to try and re-route all audio to the USB DAC but it doesn't work for everything.
My issues are:
- The FM radio plays through the internal pre-amp/amplifier.
- The volume control (whether through the touchscreen on the menu, or using the hardware knob) does not affect the USB device - there is no way to change it's volume from the head unit this far.
I'm ready/willing to flash/hack this unit as best I can, can't brick it as it belongs to a client (fingers crossed) but I definitely want to use the USB DAC full-time.
If I could find a way to loop the RCA inputs to the optical output on the UCA222 (maybe a custom app) that would be enough to route the radio output through the optical but that's definitely not ideal.
There has to be other people wanting/needing to do this! These units DACs leave a lot to be desired (I'm being nice) and there's a huge selection of great USB DACs.. Heck, in my configuration I won't even be using the DAC in the Behringer - it'll be all digital until it hits the Audison processor/amp with it's internal DAC feeding it's internal amp and a pre-amp that outputs to the separate sub-woofer amplifier (AP1D).
I have the deck setup on my desk right now hooked to a power supply and booted, on WiFi and ready for hacking. What can we do?
From what I've read the MCU controls all the hardware buttons - though I'm not sure it'll be required to mess with it..?
How does Android see the internal audio chip? I know the MCU communicates with it over SDIO, does android as well? I guess no as I read another thread that has a hack/app allowing more control over the audio chip by interfacing one the SoCs GPIO/SDIOs to the chip.
So, how does the radio app work then? Does it just send a signal telling the radio chip to route its audio to the audio chip? Or does Android actually see some sort of audio device for the radio? If it just tells the audio chip which "source" to use and the radio chip outputs directly to it, I'm not sure there's going to be a way to get radio over digital without a converter box to convert that analog output to digital..
All other Android outputs shouldn't be a problem, from what I can tell everything else is already playing over USB for me.. except the radio and volume control.. even the "beeps" you hear when adjusting the volume come over the internal audio device not USB..but Google Voice Search and YouTube work over USB fine..
---------- Post added at 03:05 AM ---------- Previous post was at 03:04 AM ----------
I find it odd that your seeing pops/clicks.. I have had no issues and fully stable audio from the apps it does work from.
forbiddenera said:
Hi,
I am also very interested in using USB Audio on a PX5.
I have an EONON GA7150A 32GB BMW unit.
MCU is "MTCD_WWW_V2.54b_2", Build is "px5-userdebug 6.0.1 MXC89l user.hct.20170617.171922 test-keys"
I run a car audio / performance / engineering company. We're doing a SQ install on a 04 BMW M3 with all Audison Prima gear going to an Audison Bit 8.9 amp/processor.
I got a Behringer UCA-222 hoping to use it - plugging it into my tablet (Samsung Tab S 8.4") - it works perfectly without any configuration, so I had hoped it'd work with the Android HU as well.
Plugging it into the Android HU - it DOES work - I can play audio from any apps (YouTube, Google Voice Search both output to the USB device) - I have installed SoundAbout Pro to try and re-route all audio to the USB DAC but it doesn't work for everything.
My issues are:
- The FM radio plays through the internal pre-amp/amplifier.
- The volume control (whether through the touchscreen on the menu, or using the hardware knob) does not affect the USB device - there is no way to change it's volume from the head unit this far.
I'm ready/willing to flash/hack this unit as best I can, can't brick it as it belongs to a client (fingers crossed) but I definitely want to use the USB DAC full-time.
If I could find a way to loop the RCA inputs to the optical output on the UCA222 (maybe a custom app) that would be enough to route the radio output through the optical but that's definitely not ideal.
There has to be other people wanting/needing to do this! These units DACs leave a lot to be desired (I'm being nice) and there's a huge selection of great USB DACs.. Heck, in my configuration I won't even be using the DAC in the Behringer - it'll be all digital until it hits the Audison processor/amp with it's internal DAC feeding it's internal amp and a pre-amp that outputs to the separate sub-woofer amplifier (AP1D).
I have the deck setup on my desk right now hooked to a power supply and booted, on WiFi and ready for hacking. What can we do?
From what I've read the MCU controls all the hardware buttons - though I'm not sure it'll be required to mess with it..?
How does Android see the internal audio chip? I know the MCU communicates with it over SDIO, does android as well? I guess no as I read another thread that has a hack/app allowing more control over the audio chip by interfacing one the SoCs GPIO/SDIOs to the chip.
So, how does the radio app work then? Does it just send a signal telling the radio chip to route its audio to the audio chip? Or does Android actually see some sort of audio device for the radio? If it just tells the audio chip which "source" to use and the radio chip outputs directly to it, I'm not sure there's going to be a way to get radio over digital without a converter box to convert that analog output to digital..
All other Android outputs shouldn't be a problem, from what I can tell everything else is already playing over USB for me.. except the radio and volume control.. even the "beeps" you hear when adjusting the volume come over the internal audio device not USB..but Google Voice Search and YouTube work over USB fine..
---------- Post added at 03:05 AM ---------- Previous post was at 03:04 AM ----------
I find it odd that your seeing pops/clicks.. I have had no issues and fully stable audio from the apps it does work from.
Click to expand...
Click to collapse
That's cool. I suppose you're member of Strictly Sound Quality group on Facebook ?
I'm really into SQ as well, Pioneer Premier / Hivi amps, MiniDSP C-DSP 6X8, Wavecor/Peerless 3 way active.
Anyways, back on topic: You say your Behringer UCA-222 outputs music without problem with regular players, but does it play in stereo ? Because my PCM2704 also plays audio nice without any click/pops noises but it output both channel mono, so no stereo effect, every sounds plays on both Left and Right. Sounds pretty dull for a SQ setup, it stages like poop lol. I only get stereo out of my PCM2704 if I play it through USB Audio Player Pro app, because that app uses his own USB audio driver.
For you FM Radio routing problem, is there I way to sum input channels on your DSP ? IE: With my MiniDSP I can play both SPDIF and RCA Inputs at the same time on specified output channels.
Thanks for your participation btw. :good:
Thought about getting a minidsp but the beringer was available locally and as I'm actually not using the DAC within it, I didn't care.
The 222 does have a monitor switch which sums all inputs to the 1/8 headphone jack but not over optical.
I could potentially write a small background app to sum the rca input on it to the output constantly but still have the volume control problem.
Video of interface.. I'll make a demo on how the USB audio actually works shortly, I'll install a frequency generator app so I can test stereo for you.
Happy New Year guys!
1. All Rockchips headunits (rk3066/3188/3288/px3/px5) have a big problem with their DWC-OTG USB 2.0 controller kernel driver from Designware/Synopsys.
This driver generates a huge amount of interrupts on usb bus (about 15000 per second under load and 8000 minimum without any use of usb devices). So any wide streaming devices like USB-DACs, USB-CAM, EasyCAP and others cannot properly function. USB-DACs on samplerates higher 44100 or 48000 Hz and bit depth higher 16 bit generate many pop and clicks in sound or just noise. All usb streams are very slow, even copying files from usb flesh to sd card.
This problem is well known and it has the resolution - kernel driver needs to be patched.
Here are some links:
http://hwswbits.blogspot.ru/2013/09/dwc-usb-interrupt-spam-in-rockchip-socs.html?m=1
https://www.google.ru/amp/s/ideechaniz.wordpress.com/2014/02/26/dwc-otg-drivers/amp/
We have not kernel sources to patch it. Any open sources will not go because of many special functions of our HUs have been compiled into kernel. I wrote about this to SHEN ZHEN KLYDE ELECTRONICS CO twice, but no reaction (I have their HU).
So you cannot play sound higher then 16 bit 44100Hz or 48000Hz. If you try 24 bit and/or 96kHz you can hear clicks and pops or just a noise. The first step to make the situation better is to get usb-dac/converter with only FULL-speed (12Mb/s) usb-reciever chip, like sa9023, te7022, pcm2704(6) (mono!) etc. Unplug all usb devices except usb-dac from usb. Note that wifi and processor's loads affect too. Edit /etc/audio_policy.conf to limit sr and bd to 44100 and 16 for usb_device section. If you want to use your high speed usb-dac you can try to find and use a full speed usb hub on ali or ebay.
2. All android HUs for now have mcu and android boards inside. All apps like youtube, navigation, poweramp etc are sounding from android board and all of them can be routed to play through usb-dac using usb audio function of android. But dvd, bt hands-free, radio are located on and managed by mcu board. So sound from them does not going to/through android board. The only one way to get their sound on your car audio processor is connection of rca-outs and set processor to auto switch between analog and digital inputs by signal determination (helix dsp and many others can do that).
3. The volume. The best way for SQ is to use the dsp's volume adjustment. Note for digital volume adjustment every -6bB from max level excludes 1 bit from effective bit depth. So you loose your sound quality (dynamic range) by digital volume adjusting on HU because you can only have 16bit output (see 1). But if you WANT to do it there is one difficult way - write your own app service to catch mcu's broadcast commands for volume adjusting and then send alsamixer's comnands to change usb dac volume same level (need to install alsa). I made it for rk3066/rk3188 HUs on petrows microntec headunit service. Hope this help https://github.com/petrows/RK3066-Headunit-service
https://www.google.ru/url?sa=t&sour...MQ5YQBCCcwAA&usg=AOvVaw2W8hsXylKrMeQRC2R2mOVt
This service also can send buttons presses to Poweramp, USB Audio Player Pro, Spotify, PCRadio etc. But it is for MTCB, not for MTCD HUs. I dont know a difference of Microntek services of this versions of HUs. So I cannot say will it work or not on MTCD.
Question which has better sound?
Chich output > dsp > amp or
Usb dac > amp
??? I think the sound should just be good with a dsp or im wrong?
aluver said:
All apps like youtube, navigation, poweramp etc are sounding from android board and all of them can be routed to play through usb-dac using usb audio function of android.
Click to expand...
Click to collapse
Thanks man for the detailed post.
How do i do this. Is it in the developer options where we select to use Audio source for USB . What would happen in case we have multiple USB devices in use?
Thanks in advance.
kaderekusen said:
Question which has better sound?
Chich output > dsp > amp or
Usb dac > amp
??? I think the sound should just be good with a dsp or im wrong?
Click to expand...
Click to collapse
What do you mean under "Chich output". RCA? I think dsp cannot make the sound of HU's RCA better. It has a very poor quality with low voltage - so you get a lot of noise and "unsharped" sound.
---------- Post added at 11:39 AM ---------- Previous post was at 11:29 AM ----------
piyush7243 said:
Thanks man for the detailed post.
How do i do this. Is it in the developer options where we select to use Audio source for USB . What would happen in case we have multiple USB devices in use?
Thanks in advance.
Click to expand...
Click to collapse
I don't think dev options have it. I think usb audio must work from the box on android 6 firmware, but it may depends from firmware version. To dermine usb audio driver exist in kernel just plug in your usb-dac and view file /proc/asound/cards - it will show you all plugged sound devices for this moment. But note at first you need to entirely stop all installed direct players like UAPP, Hybi, NeutronMP etc.
aluver said:
[/COLOR]I don't think dev options have it. I think usb audio must work from the box on android 6 firmware, but it may depends from firmware version. To dermine usb audio driver exist in kernel just plug in your usb-dac and view file /proc/asound/cards - it will show you all plugged sound devices for this moment. But note at first you need to entirely stop all installed direct players like UAPP, Hybi, NeutronMP etc.
Click to expand...
Click to collapse
Dev options have it and i have enabled it there as well. but not sure on which USB port. Also currently i am at the highest firmware level and ROM level. No 3rd party USB driver is installed, still cant get the USB audio out. I have even replaced the audio_policy.conf.
I will check if the device is getting detected or not
piyush7243 said:
Dev options have it and i have enabled it there as well. but not sure on which USB port.
Click to expand...
Click to collapse
Good info. Is your firmware from enthusiasts or from a producer?
You have to use USB port for 3g-modem - it must be otg. But on my Klyde rk3066 mtcb hu I have all 3 usb ports working with dac.
audio_policy.conf must be in /etc for proper usb audio functionality.
Didn't understand about usb modem. I use 2 HDD and a USB DAC .the firmware is Hotaudio Dasaita default one. Do you have the audio_policy.conf file for my reference
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I mean otg usb port is usually marked "3g-modem" or like that.
audio_policy.conf may be different for our HUs. Besides, I have android 4.4.4 rom. But I attach my 2 versions of audio_policy.conf. The second version is from ROM that contains a file /system/lib/hw/audio.alsa_usb.rk30board.so. So policy contains alsa_usb section.
What is your result with driver?
aluver said:
I mean otg usb port is usually marked "3g-modem" or like that.
audio_policy.conf may be different for our HUs. Besides, I have android 4.4.4 rom. But I attach my 2 versions of audio_policy.conf. The second version is from ROM that contains a file /system/lib/hw/audio.alsa_usb.rk30board.so. So policy contains alsa_usb section.
What is your result with driver?
Click to expand...
Click to collapse
Thanks for putting this here. Btw nothing was marked on my USB cables so swapping usb helped and one of them worked on apps.
Now another quick question. Tried Poweramp but it didn't see the usb DAC. Jet audio would hang. Any other music apps which doesn't use its proprietary driver.
I can use UAPP but it seems that it locks the usb DAC and doesn't allow the other apps to have access.
With UAPP it says usb device initialised but yesterday no such message.
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piyush7243 said:
Now another quick question. Tried Poweramp but it didn't see the usb DAC. Jet audio would hang. Any other music apps which doesn't use its proprietary driver.
Click to expand...
Click to collapse
Did you use Poweramp v3 alpha? What version? Better use v703 for your android 6. What samplerate do you have in audio_policy.conf at usb_device section now? Need to limit it 44100 and 16 bit depth. Poweramp 3 may not work with usb-dac directly in case of many software and hardware combinations reasons. But you can use Poweramp v2 - it may work as other apps through android kernel usb audio driver.
---------- Post added at 08:44 AM ---------- Previous post was at 08:29 AM ----------
piyush7243 said:
I can use UAPP but it seems that it locks the usb DAC and doesn't allow the other apps to have access.
With UAPP it says usb device initialised but yesterday no such message.
Click to expand...
Click to collapse
I wrote earlier about this. All direct players always lock usb-dac. I am not sure but seems to be Poweramp v3 alpha does not lock dacs, internal at least. Try it.
I am back , after the reboot, the usb DAC is not being used again. Ughhhh. Need to break my head more to get to bottom of this behaviour.
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What is a 'WWW' MCU? Anyone using USB Audio?

Hi,
I run a car audio firm, we have a PX5-based unit a client ordered.. The MCU version is "MTCD_WWW_V2.54b_2" .. Our goal is USB audio working proper, among a few other things (better interface if possible, better apps, better SQ stuff)
I haven't seen a "www" mcu anywhere? It's sold as an EONON GA7150A..
Anyone know anything about this MCU? If it's compatible with any others or anything like that? I definitely would like to root it, update the ROM to something better, get rid of the "Windows Mobile" part of it which was, IIRC, advertised as the ability to 'boot' between Android and Windows but is actually just a different interface theme from the home screen.. Also want to do whatever we can for sound quality and smooth experience.
I should note that, as a car audio company (in Canada), we are seriously considering producing our own Android units.. likely 'producing' would consist of getting units like a px5, branding them and primarily, having a SOLID software system built for automotive use. I think a lot of these units are a great start and are ALMOST there for a lot of things but..some of the interface stuff is rushed, not translated great, etc.
What I'd like to see is an Android unit, priced like these ones usually are, but with *really* good class A interfaces. The kind of experience you'd expect on a Samsung phone or a Pioneer headunit. I personally have been using my Samsung Tab S 8.4" in my car as my 'head unit' (paired with a Pioneer single din for a hardware volume knob and some easy control) for along time and I would not want to ever go back.
Here's a short video of the interface and version info..
My eventual goal is getting USB audio working decently. It does work for most Android apps but the volume control only controls the internal audio chip, and the radio app routes through the internal audio chip as well.. I assume perhaps other sources like DVD and line-in would as well, I haven't verified but I will pretty quick here. I plan on making another video showing what works/what doesn't/how it works.
I'm hoping for a software only solution but am happy to hack the hardware if needed. I'm using a Behringer UCA-222 as a "DAC" (same as 202 but red in color) but won't actually be using the DAC in it but only it's optical output into an Audison Bit 8.9 DSP/Amplifier.
There's the possibility of routing the px5's audio output RCA's to the Behringer's Input and 'monitoring' that input to the optical output via software but that doesn't solve the fact the volume control does nothing for apps when using the USB.. Eg, youtube plays through USB/optical fine but volume control doesn't change the volume..Radio plays through the px5's audio chip and volume control controls that, and shows on screen.. I could force everything to play thru the px5 audio chip and then monitor it to optical but that defeats the purpose of what I'm trying to do completely (full digital audio to the amplifier).
I'm willing to sacrifice some sources re-routed like that though, eg, the radio would be fine as it already sounds ****. Aux in also doesn't sound great usually and won't be used in this car anyway. DVD would be nice to have optical out as well but
I'm currently still searching for a schematic/block diagram for these devices, this would probably answer a lot of my questions like.. I'm curious whether audio from any of the other onboard devices (radio, dvd, aux in) go through Android at all or whether they're directly sourced to the output chip.
If it's the latter - that sucks - but I wouldn't be surprised. I have read the thread about the hardware hack to allow android control of the audio chip but I don't see this giving me the functionality I need. If it is wired like this, and I can get the other components (eg. radio chip) to output their audio to Android, digitally somehow and have Android push it to the USB audio device that'd be cool.
Is no one else using a USB dac on any of these units? I have many years experience coding, hacking, electronic engineering, tinkering, etc. including Android but I haven't done many of these Android Head Units.. A lot of times we use tablets instead! But this client wanted OEM look..so we thought we'd give it a shot.
The difference between the audio quality from the internal DAC and the USB audio device's optical routed directly to the DSP (digital to the power amp) is definitely noticeable, even with there being very little noise picked up in our interconnects.
Hi,
I can help you only with WWW MCU,
forbiddenera said:
Hi,
I run a car audio firm, we have a PX5-based unit a client ordered.. The MCU version is "MTCD_WWW_V2.54b_2" .. Our goal is USB audio working proper, among a few other things (better interface if possible, better apps, better SQ stuff)
I haven't seen a "www" mcu anywhere? It's sold as an EONON GA7150A..
Anyone know anything about this MCU? If it's compatible with any others or anything like that? I definitely would like to root it, update the ROM to something better, get rid of the "Windows Mobile" part of it which was, IIRC, advertised as the ability to 'boot' between Android and Windows but is actually just a different interface theme from the home screen.. Also want to do whatever we can for sound quality and smooth experience.
Click to expand...
Click to collapse
tha same question (#1956) i read in this thread https://forum.xda-developers.com/an...-head-unit-discussion-thread-t3573881/page196
it should be KLD (klyde), you can read the answer in post #1959
Thanks for the pointer.
Hi,
I uses the newsmy carpad since 2 yrs with android box with wince interface and same issue of radio, bt and dvd being analog while the android side of things is 100% digital output via the included hdmi.
I put aside my alpine pxa-h900 and installed the helix dsp pro with auto switching of input with priority on digital input and use internet radio apps, android bt apps and plugged in an usb portable drive for dvd/cd.
Cheers.
Richard
Singapore

External USB dongle on PX5

So, the Bluetooth function in Android Headunits act differently than an Android tablet would, for one, it's a handsfree receiver that does not allow (correct me if I'm wrong) uplink with another device.
I have a DSP amp combo that uses BT to connect to an Android phone/tablet, which works fine, but my Dasaita PX5 won't connect to it. It just sees it, pairs, but doesn't connect.
Is there any way I can use a generic Bluetooth USB dongle to connect to it instead? Or is there any other way to allow connection with other BT devices (I have no luck in connecting OBD dongles too, BT or Wi-FI).
Thanks.
The device isn't an MTCB, being a dasiata it's likely an MTCD.
The answer to the BT question is no, you can thank the developer of the device for the hacked BT implementation.
Requesting mod moves to MTCD general.
Cheers! I've been out of touch for a bit and completely forgotten about the MTCx denominatin,
Thanks.
marchnz said:
The device isn't an MTCB, being a dasiata it's likely an MTCD.
The answer to the BT question is no, you can thank the developer of the device for the hacked BT implementation.
Requesting mod moves to MTCD general.
Click to expand...
Click to collapse
So just to be clear before I go down this path, there is NO external USB bluetooth module that will work with an MTCE head unit? Even if the USB module somehow uses the driver/firmware in the factory settings dropdown?

LineageOS Sound from Dockingstation 3.5mm audio jack

Hi all,
with the web overflowing ~30 years after it's invention I can't g**gle this...
UPDATE 1: restored the S4 to a stock Android 5.0.1. Settings > My Device > Accessories > enable "Audio Output Mode" => Plays music through the dock's jack allright => Conclude: must be somehting with Lineage. Will try a more recent AOSP-10 based rom later...
/UPDATE1.
UPDATE2: tried with an AOSP 10 based HavocOS version. Doesn't work, Options are the same as in the LOS based ROM. => is there no non-stock rom out there supporting the damn samsung docks!?
/UPDATE2
UPDATE3: now raised this question in the Samsung S4 Q+A forum; please excuse the double-posting; mods may close this here (but please don't delete as I didn't take the full details over)
Audio through "Mulitmedia Dock" 3.5mm jack?
Hi all, tl;dr: how to make a Samsung dock work like in stock 5.0.1 years ago with any more recent custom rom? I can't get my I9506 to route audio through the dock except if I use the old stock rom. (Note: posted this question with a few details...
forum.xda-developers.com
/UPDATE3.
-- original post below --
tl;dr: how to get 3.5mm audio jacks on Samsung docking stations to work?
I have two devices, Samsung Tab 2 and Galaxy S4 (yes, old, but for what I'd like to do still what you want for "no money").
For each I have an original Samsung Docking Station ("Desktop Dock EDD-D1E2BE" and "Multimedia Dock EDD-S20EWE", respectively), each with a 3.5mm audio jack at the back.
EDIT:
- The Tab2's station is "stupid", i.e. it only splits out the (30pin?) connector into the data / power lines (keeping the same plug / connector geometry) and the audio leads. No chips inside that dock.
- The S4's dock contains a usb hub (3 Ports), HDMI connector, and the audio jack and micro-USB port. Several chips inside. Not sure if there's anything like a USB-connected audio chip ("DAC"?) in there, would have to get the glued PCB out to get some understanding (maybe). So here LOS might need some sort of "driver" to talk to the audio DAC and then the jack?
/EDIT.
The Tab 2 runs a dated Lineage 14.1 (Android 7.1.2), and the S4 (ks01ltexx) a more recent LOS 18.1 / Android 11.
Want to use media apps (radio streaming ...) to send audio output through that jack to our living room amp. Yes, I could plug the 3.5mm audio cable into the device's own jack, but that's ugly as hell. Plus, want to be able to take the device (which wouldn't matter in the end, happy to get one combo to work) out of the dock, select the stream etc, and once it plays (then through the crappy device's speakers) set the device back into the cradle and have it re-route through the rear jack - without plugging a cable.
Doesn't work in either, and I can't find any related options in the settings / get it to work.
On the LOS 14.1, there's Settings > Sounds > Other Sounds > Dock-Speaker (?) (translating from my system language here, might not be fully correct) where there's two options "All Audio Sources" and "Only Audio Sources from Media" (wording doesn't really make sense, also not in my native language). Neither does change anything.
Also on the LOS 14.1, in the Developer Options, there is the selection for the "USB Configuration" offering "charging", "MTP", "PTP", "RNDIS", "Audio Source", and "MIDI". None of them does the trick, and "MIDI" can be selected but is never realy "set", i.e. it reverts back to what was set before when entering this option screen again.
In the LOS 18.1, "Audio Source" and "MIDI" aren't there, I have "file transfer" (I think that's MTP in earlier versions), "USB tethering", "PTP", "no data transfer" (which would be "charge only" I think).
On both, another developer option is "disable USB audio routing", which is switched off (so it should allow to route USB audio to the dock I would expect).
All these options in various combinations make no difference on either device. Also, I'd think that making it work should be possible even without any dev options.
Is there's a general issue with docking stations, audio and LOS? Have been through various versions over the years with the Tab 2 and occasionally re-tested the dock/jack thing - never worked, but never really looked into it. Only thing not tried is to go back to a stock samsung FW (which would be an Android 5.0 or so for the galaxy S4, possibly even worse for the Tab2).
Q: is it generally possible to enable the sound via the docks? Anyone using similar combinations with any LOS or other ROM?
Cheers.

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