Develop Bugs

Joying MTCB HU, USB connections.

Just installed a Joying:
. SKU: JY-UL124 . Quad Core Android 5.1.1 Lollipop OS Capacitive 7" High Definition for Universal Double Din . CPU: RK3188 1.6GHz Cortex A9 Quad Core, Resolution 1024*600. RAM：DDR3 1G, 16 GB memory
To my 2014 Australian Hyundai Elantra.
I waited to get the latest HU from Joying that has an unrated mother board and USB/ Comms board. With Lollipop 5.1.1. the unit performs very well with none of the problem previously mentioned on these pages. The internal and external mics are clear and the Bluetooth systems are perfect. Unit has been rooted and I don't seem to need for apps so I won't changed the software.
The dimming for the button and the screen to follow the vehicles rheostat was fixed by making a circuit to invert and amplify the rheostat output to the HU ill line. Work's well, Kudos to the guys at the Subaru forums.
I had one bug fixed by Joying when the GPS nav was muted whenever I plugged in the DVR front camera. Joying quickly sent me a link to re flash my firmware and the problem was fixed. I have them currently looking into a bug when I view the DVR input shown on the HU I get lots of flashing to the screen in all pixel settings. I have been told this will be fixed in the next firmware update soon.
One problem that I can't solve is when I try to use my vehicles Multimedia Jack located in my center console. There is a Aux and USB jack there. All wiring from console to HU is complete. If I connect a USB stick to the Jack in the console then then HU struggles to connect and gives up. If I interrupt the USB plug and socket behind the HU then I am able to use the USB correctly. Looking at the car wiring diagrams there is a amplifier cct behind the Multimedia Jack supposedly to amp up the USB to HU. Doesn't seem to work?
Any ideas appreciated.
Duke
If anyone has any ideas on

i have nothing to add, other than interested to see what the result is. Are you saying that your car comes with a built in hub in the console, and you are trying to make that USB port in the console work to the Joying head unit? my vehicle is similar, and I would like that to work as well

Update
Yes I have a console hub I guess.
The book calls it a multimedia center. Just an Aux port and a USB port or Jack in the tidy bin in the center console. If I by pass the Jacks and directly put the USB stick into the USB tail from the radio then it works fine. When I plug into the console port it tries to read it and fails. The HU then reports a read fail, have tried other known working USB sticks.
I have inspected behind the console jacks and found a cct board attached to the Jacks and then to the car wiring. From looking at the diagrams of the car previous to mine I see a cct board containing what looks like an amplifier. Tracing the car wiring to the radio input connectors seems to be OK and the wiring correct. Voltages at the radio connector are right in that there is 5v +ve, negative - earth and the center pins are data as they should be.
The console Jacks
w.hemanual.org/multimedia_jack_description_and_operation-2037.html
The wiring for same (mine is same but more complex)
w.hemanual.org/multimedia_jack_schematic_diagrams-2036.html
Really bugs me not to be able to access that USB input Jack esp as the radio is a great unit.

You need to post this question in the MTCD (Lollipop) hardware thread. This thread is for MTCB (KitKat) units. The hardware in the MTCD headunits are very different than the MTCB headunits.

bsavoir22 said:
You need to post this question in the MTCD (Lollipop) hardware thread. This thread is for MTCB (KitKat) units. The hardware in the MTCD headunits are very different than the MTCB headunits.
Click to expand...
Click to collapse
When I tried to repost this in MTCD I get this.
vBulletin Message
To prevent spam, you must have a higher post count in order to make a new thread in this development section. But feel free to make new thread in the non-development sections like General, Q&A, etc. Thanks for your understanding!
Am I still in the wrong section?

Yes, the MTCD thread is for the headunits with 5.1.1. The hardware changes and software are different. Send one of the admin a message and tell the why you need to get the permissions to post. I had to do that some time ago. Just make sure you follow the rules when post or you can have you account suspended or whatever the moderators deem necessary.
Sent from my SM-N910T3 using Tapatalk

Posting
Ok thanks for that. I don't seem to be able to find how to "Send one of the admin a message" Can you help?

Just for info, there are both MTCB/C and MTCD/E Lollipop units.

Pumpkin unit (Klyde 6.2" RK3066) Canbus problem ..

Hi all,
I am trying to install the above into an Audi A4 which is a canbus vehicle.
I got everything plugged in and it all looked to be working fine but after 2-3 minutes the unit always switches itself off. I have noticed the Canbus adapter always gets very hot as well just before the unit switches off.
Could I have connected something incorrectly for this behaviour to occur?
Thanks

Please be more specific.
Do you have ISO connectors?
The CanBus module should be allready wired to the comnector. It was not? If no, post the wiring diagram received (maybe you feed 12 V in a 5V input?....).
În order to get help post pictures and more info.

Hi. The fitting kit I have used is the following;
http://caraudiosecurity.com/ctkau02-audi-a4-2002-2006-complete-double-din-facia-kit
The Canbus adapter is plugged in via the attachment to the ISO cable.
Let me know if you need any pictures.
Thanks

I'm sure there is no easy way to find the problem.
I would do the following :
First make sure that all pins in all connectors are firmly in their place (see below the example).
Get correct pinout data for all connectors (Car connectors, HU, the adaptor kit and the CanBus module and also the pinout for the old stereo). When searching for the car connectors pinout make sure you find the correct one (year, model, audio system type, etc).
After having all the data you should search for any mismatch (power instead of data, different voltages, etc).
I recomend this beacuase I bumped in a similar problem with my car. I have a Mazda 6 and for the same model and year the car Hu connector differs for the Bose system version and the non Bose version, and the pinout of the adapter and Hu is not taking in consideration this posibility. Therefore I had to cut and reconnect some wires.
And one more thing : when I installed my Hu, some pins slipped out of their slots inside the connectors and my CanBus module was beep-ing constantly and the Hu was not starting at all. I had to use a very thin metal rod to push them back into position (with the connectors plugged in).

Thanks for your help. It turns out a Parrot bluetooth module was installed at some point and they have a good mess with the wiring and piggubacked onto the cars wiring. I am having to use that to power the unit now as it stops it turning off after 3 minutes. My next problem is that I don't have the steering controls option available in the settings menu. Any idea why?

If you are using CanBus you do not need that menu. The Hu has two 5V out and two inputs. If you have non CanBus Swc you need to take the 5V wire, pass it through your Swc and then to the Hu Swc input (the clasic controls usses resistors with different values for each button that atenuates the 5V from the Hu in different values for each button pressed and the Hu read that value through the swv input). So if your 5V wire and Swc input is not connected, you will not have the menu available. Once connected you must first go to factory menu and define each button (see the user manual))

Marmalux said:
If you are using CanBus you do not need that menu. The Hu has two 5V out and two inputs. If you have non CanBus Swc you need to take the 5V wire, pass it through your Swc and then to the Hu Swc input (the clasic controls usses resistors with different values for each button that atenuates the 5V from the Hu in different values for each button pressed and the Hu read that value through the swv input). So if your 5V wire and Swc input is not connected, you will not have the menu available. Once connected you must first go to factory menu and define each button (see the user manual))
Click to expand...
Click to collapse
Thanks. I've attached some pictures to show how the unit is connected to the Canbus adapter.
Key1 5V is connected to its equivalent going to the Canbus adapter.
Key2 5V is as above
GND is as above
Do I have it correct and am I just required to correctly map the buttons now?
Thanks

Still can't get this working.
Should I reset the headunit, update MCU and software or does it look like my wiring is wrong?
Thanks

No one can help you without being there. If you do no have the skills to do it yourself you should go to a electronics service.
As I said, you have to analyze all data. You must get all pin-outs and characteristics for your car.
You must know if your Swc is resistive or Can-bus.
With the car main stereo connectors pinout you will see what you have (resistive Swc, Can-bus wires, external amp signal, etc) and theirs place in the connector.
With the Hu pinout you will know what does the Hu can provide and what pins you should use.
And in your case you have a adapter in the middle, for witch you also need the pinout to make sure that everything is routed correctly.
After you have a clear diagram for your car you must check if fizicaly everything is as it should be.
How to get the pin-outs?
The Hu pinout should be on a sticker on the Hu itself.
For the car connectors you must first decode you vin and get info like year, options, version (usualy a more detailed pinout you find if you search the old stereo pin-out by it's exact make and model).
And for the adapter you must get it from the seller or from the Internet.
You said that before you, someone made modifications to wiring; this is one more reasons to get all informations and make yourself a clear wiring diagram for you to be able to start troubleshooting.
I realy wish I could help more but I can't, and there is nobody else that can give you help without being there to see (otherwise it would allready said sommething)
Best regards!

Is PAC SWC Module necessary?

I have an Eonon branded RK3188 unit - I replaced an older Pioneer system that a previous owner of the car (2005 Jeep Grand Cherokee) had installed - his setup used a PAC SWC module, which the guys who installed my Eonon used as well - was wondering that since the unit itself seems to have wiring specific to the steering wheel function, if this module is necessary at all? I ask because there on the left side SWC, my middle button mirrors another button, is not recognized independently - I had previously installed a different Android Head Unit, and with that one, the buttons functioned properly -

Jacklad said:
I have an Eonon branded RK3188 unit - I replaced an older Pioneer system that a previous owner of the car (2005 Jeep Grand Cherokee) had installed - his setup used a PAC SWC module, which the guys who installed my Eonon used as well - was wondering that since the unit itself seems to have wiring specific to the steering wheel function, if this module is necessary at all? I ask because there on the left side SWC, my middle button mirrors another button, is not recognized independently - I had previously installed a different Android Head Unit, and with that one, the buttons functioned properly -
Click to expand...
Click to collapse
If your original car SWC system is resistive then you don't need the box.

halloj said:
If your original car SWC system is resistive then you don't need the box.
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Click to collapse
Thanks for that - now how do I know if it's resistive or not? is there a quick test, or a model chart? Thanks for any help - probably dumb questions, but I have no experience with them -

Jacklad said:
Thanks for that - now how do I know if it's resistive or not? is there a quick test, or a model chart? Thanks for any help - probably dumb questions, but I have no experience with them -
Click to expand...
Click to collapse
There must be a Jeep Grand Cherokee forum or a ask a dealer.

I have a 2002 Jeep Grand Cherokee and I use SWC without PAC SWC module. You have only to take a couple of wires from the connector under the steering wheel to the radio (yellow connector if I am remember right), disconnecting the original connector.

royalhawk2002 said:
I have a 2002 Jeep Grand Cherokee and I use SWC without PAC SWC module. You have only to take a couple of wires from the connector under the steering wheel to the radio (yellow connector if I am remember right), disconnecting the original connector.
Click to expand...
Click to collapse
Thanks for that info - I'll see what I can find

Jacklad said:
Thanks for that info - I'll see what I can find
Click to expand...
Click to collapse
Refer to this diagram (sorry for italian)

royalhawk2002 said:
Refer to this diagram (sorry for italian)
Click to expand...
Click to collapse
Hence, red/yellow should be connected to key1 and red/black should be connected to Key ground. NO box, no nothing.

halloj said:
Hence, red/yellow should be connected to key1 and red/black should be connected to Key ground. NO box, no nothing.
Click to expand...
Click to collapse
Confirmed! Remember to disconnect the Pin 3 & 4 to the BCM side.

royalhawk2002 said:
Confirmed! Remember to disconnect the Pin 3 & 4 to the BCM side.
Click to expand...
Click to collapse
Thanks so much - I'd the bcm one the connections going to the radio, or part of the car harness?

Jacklad said:
Thanks so much - I'd the bcm one the connections going to the radio, or part of the car harness?
Click to expand...
Click to collapse
Did you look at the drawing?

Jacklad said:
Thanks so much - I'd the bcm one the connections going to the radio, or part of the car harness?
Click to expand...
Click to collapse
Did you get this going? I figured this out a few months back, myself. My truck (2005 Ram) didn't have SWAC from the factory, but I installed them myself.
What I did was cut the wire going to the MUX (connector behind instrument cluster. I made a jumper to run from the cut wire off the column and made a jumper to get to the head unit. The HU chassis is already grounded via the harness, so there was no need to make a ground. The jumper made a "Y", with one leg going to Key1 and the other to Key2. Really, I guess you could just run one wire and combine the Key wires together as the HU will sort out the resistance.
Jumper-before soldering/heat shrinking.
Done this way, it can easily be restored.

Newbie needs a little help for KLD unit

Greetings, gurus and fellow users of android head units,
I recently took the plunge and bought myself one of these head units after much browsing of the forums and trying to read up as much as I can. The exact one is shown here: https://world.taobao.com/item/528347515585.htm?spm=a312a.7700714.0.0.3Y4Xhq#detail
For those who are unable to view the link/understand Chinese, here are some quick specs:
- 10.1 inch touchscreen, 1024x600 resolution
- RK3188
- 1GB ram, 16GB storage
- Android 5.1.1
- MTCC-KLD6-V2.97 Aug 02 2016 10:35:08
Interestingly, this is only unit I've seen so far that still comes with a DVD slot, plus it comes with an external mic, which pretty much solves the issue of the crappy internal mic that many of you have experienced in the past. Also, apart from 2 USB ports that are connected to the back of the unit, there is another USB port in front, just to the right of the sd card slot and below the DVD slot.
All went well with this head unit, but there are some minor issues that I would like to ask for your help or guidance:
- 3G USB dongle is not stable - If I turn on the unit with the dongle attached first, it does not work at all. If I attach it after the unit completes booting, it sometimes will lose 3G connectivity. I have downloaded the mobile network settings app and removed all but 1 APN. Searching on the forums tell me this should pretty much be a power issue. I'm currently looking around to see if I can find a USB hub that accepts 12V DC power so I can connect to the ACC circuit and see if the issue goes away. If anyone has any other suggestions, please feel free to let me know.
- Custom firmware - I decided to try Malaysk's rom from here: http://forum.xda-developers.com/showpost.php?p=69114366&postcount=691 however, it didn't work. After updating the firmware from sd card and wiping the data/cache/etc a couple of times, all I got after rebooting the unit was a black screen and an unresponsive status bar. Booting into recovery shows me the "Block device required" message and a bunch of others that I've forgotten. Fortunately, I was able to restore via USB to a newer version of MTCC-KLD6 firmware posted here: http://forum.xda-developers.com/showpost.php?p=69206883&postcount=165 and everything still works. However, I would still like to try Malaysk's rom, and possibly in the future try 7floor's sound mod.
- Steering wheel control - According to the shop where I went to get my unit installed, my 2007 Subaru Impreza comes with only 1 wire for swc. Using the default Key Study app I was able to map the vol+, vol-, mute, mode, previous ( |< ) and next ( >| ) keys successfully. However, I noticed that sometimes, the keys would not work. Also, the unit sometimes confuses the vol+ and mute signals. Is there anything I can do to make this better?
- Screen dimming - Is there any way to dim the display brightness using the signal from the car's lights? Currently, the soft touch buttons along the left edge of the display will light up automatically when I switch on the headlights, and go dark when I turn the lights off, but the display brightness does not change. End result, I have a screen that is either too bright at night, or too dark during the day.
Many thanks in advance to all who give me suggestions and answers to my questions above. :good:

firefly_hm said:
- 3G USB dongle is not stable - If I turn on the unit with the dongle attached first, it does not work at all. If I attach it after the unit completes booting, it sometimes will lose 3G connectivity. I have downloaded the mobile network settings app and removed all but 1 APN. Searching on the forums tell me this should pretty much be a power issue. I'm currently looking around to see if I can find a USB hub that accepts 12V DC power so I can connect to the ACC circuit and see if the issue goes away. If anyone has any other suggestions, please feel free to let me know.
Click to expand...
Click to collapse
Igave up on using a 3G modem and started using a cheap USB 3G hotspot powered from the lighter socket. The headunit connects to it through WiFi and that's it.
firefly_hm said:
- Custom firmware - I decided to try Malaysk's rom from here: http://forum.xda-developers.com/showpost.php?p=69114366&postcount=691 however, it didn't work. After updating the firmware from sd card and wiping the data/cache/etc a couple of times, all I got after rebooting the unit was a black screen and an unresponsive status bar. Booting into recovery shows me the "Block device required" message and a bunch of others that I've forgotten. Fortunately, I was able to restore via USB to a newer version of MTCC-KLD6 firmware posted here: http://forum.xda-developers.com/showpost.php?p=69206883&postcount=165 and everything still works. However, I would still like to try Malaysk's rom, and possibly in the future try 7floor's sound mod.
Click to expand...
Click to collapse
The problem is with 5.1 recovery. Malaysk's latest 5.1.1 ROM from October 30 uses a 4.4 recovery and can be installed om your unit. You can also try his 4.4 ROM or @dsa8310 5.1.1 ROM
firefly_hm said:
- Steering wheel control - According to the shop where I went to get my unit installed, my 2007 Subaru Impreza comes with only 1 wire for swc. Using the default Key Study app I was able to map the vol+, vol-, mute, mode, previous ( |< ) and next ( >| ) keys successfully. However, I noticed that sometimes, the keys would not work. Also, the unit sometimes confuses the vol+ and mute signals. Is there anything I can do to make this better?
Click to expand...
Click to collapse
1 wire is pure nonsense. You have a resistive SWC and need 2 wires, one of which is GND. Find the SWC ground wire and make sure it's connected and you'll get rid of these issues.
firefly_hm said:
- Screen dimming - Is there any way to dim the display brightness using the signal from the car's lights? Currently, the soft touch buttons along the left edge of the display will light up automatically when I switch on the headlights, and go dark when I turn the lights off, but the display brightness does not change. End result, I have a screen that is either too bright at night, or too dark during the day.
Click to expand...
Click to collapse
There is an Xposed module that will dim the screen based on time of the day.

m00n61 said:
1 wire is pure nonsense. You have a resistive SWC and need 2 wires, one of which is GND. Find the SWC ground wire and make sure it's connected and you'll get rid of these issues.
Click to expand...
Click to collapse
Indeed, there are 2 wires. The SWC signal wire is connected to the Key1 wire on the unit and the SWC ground is spliced together with the unit's ground. There is another Key2 wire which presumably is for other makes/models of cars that have 2 SWC signal wires. Our conclusion is that the unit is not sensitive enough to sense the differences between the mute signal and the vol+ signal. All other SWC functions are operating normally though.
Another issue that I forgot to mention earlier, for some reason the GPS apps that I'm using (Waze and Maps.Me) are unable to automatically switch to night mode display of the maps when night comes. Any ideas as to why this is happening?

firefly_hm said:
Indeed, there are 2 wires. The SWC signal wire is connected to the Key1 wire on the unit and the SWC ground is spliced together with the unit's ground. There is another Key2 wire which presumably is for other makes/models of cars that have 2 SWC signal wires. Our conclusion is that the unit is not sensitive enough to sense the differences between the mute signal and the vol+ signal. All other SWC functions are operating normally though.
Another issue that I forgot to mention earlier, for some reason the GPS apps that I'm using (Waze and Maps.Me) are unable to automatically switch to night mode display of the maps when night comes. Any ideas as to why this is happening?
Click to expand...
Click to collapse
Your conclusion is ..., how should I put it? Not right?
Ground key2. It's a resistive matrix for **** sake. It's not a MOS-FET preamp.

m00n61 said:
Your conclusion is ..., how should I put it? Not right?
Ground key2. It's a resistive matrix for **** sake. It's not a MOS-FET preamp.
Click to expand...
Click to collapse
That was what I interpreted from your first post - SWC signal to Key1, ground to Key2. However when I tried that, the unit was totally unable to detect any SWC signal at all. On closer inspection of the wires on the unit, both Key1 and Key2 wires were marked as 5V. With SWC signal to Key1 and ground tied to unit ground, I was able to get SWC to work, albeit intermittently.

firefly_hm said:
That was what I interpreted from your first post - SWC signal to Key1, ground to Key2. However when I tried that, the unit was totally unable to detect any SWC signal at all. On closer inspection of the wires on the unit, both Key1 and Key2 wires were marked as 5V. With SWC signal to Key1 and ground tied to unit ground, I was able to get SWC to work, albeit intermittently.
Click to expand...
Click to collapse
Looking at the unit pictures it seems it has a CANBUS decoder, which explains Key1 and 2 both marked as 5V. And your car seems to have CANBUS. Not sure if Subaru also used it for SWC though, you will need the schematics. If this is the case you need to enter Factory settings (use 126 as password) and, under the Application tab select the proper CANBUS setting. But then, both wires need to be connected. I presume you did not get a proper harness but the zillions of wires as in the picture so I suggest you get the proper one for your car. It will probably be easier to get a standard ISO wiring for the unit and a ISO/car connector adapter wiring.

m00n61 said:
Looking at the unit pictures it seems it has a CANBUS decoder, which explains Key1 and 2 both marked as 5V. And your car seems to have CANBUS. Not sure if Subaru also used it for SWC though, you will need the schematics. If this is the case you need to enter Factory settings (use 126 as password) and, under the Application tab select the proper CANBUS setting. But then, both wires need to be connected. I presume you did not get a proper harness but the zillions of wires as in the picture so I suggest you get the proper one for your car. It will probably be easier to get a standard ISO wiring for the unit and a ISO/car connector adapter wiring.
Click to expand...
Click to collapse
I've look through the service manual, the SWC controls are connected to the CAN communication system, but I'm not sure how this works. Will research this further, thanks.
In other news, I've managed to get Malaysk's latest firmware running on my unit, like you said it's due to the recovery. Many thanks for that. One thing I've noticed, the blank screen button in the status bar no longer works (The one near the return button on the right, not the screensaver button on the left). Is this normal?
Also, do you have any idea on the navigation apps map night mode issue?

firefly_hm said:
I've look through the service manual, the SWC controls are connected to the CAN communication system, but I'm not sure how this works. Will research this further, thanks.
Click to expand...
Click to collapse
Something like this should help
firefly_hm said:
In other news, I've managed to get Malaysk's latest firmware running on my unit, like you said it's due to the recovery. Many thanks for that. One thing I've noticed, the blank screen button in the status bar no longer works (The one near the return button on the right, not the screensaver button on the left). Is this normal?
Click to expand...
Click to collapse
Check the mtc-status bar module in xposed (and mtc-statusbar.ini). It could be disabled
firefly_hm said:
Also, do you have any idea on the navigation apps map night mode issue?
Click to expand...
Click to collapse
No idea. Apart from app configuration settings - night mode may be disabled.

firefly_hm said:
That was what I interpreted from your first post - SWC signal to Key1, ground to Key2. However when I tried that, the unit was totally unable to detect any SWC signal at all. On closer inspection of the wires on the unit, both Key1 and Key2 wires were marked as 5V. With SWC signal to Key1 and ground tied to unit ground, I was able to get SWC to work, albeit intermittently.
Click to expand...
Click to collapse
From what I have seen of the MCU code itself, I don't think that Key2 is meant to be a ground reference for Key1. They are both handled the same way in the code -- as separate analog inputs. When they change and become stable, the MCU sends a message to the Android cpu. So if Key2 is being used as a reference it has to be happening on the Android side of things. Looks to me far more likely that Key2 is just used for cars with more than one resistive ladder.
If your SWC keys work but are sometimes unreliable, you might try placing a small bypass capacitor across key1 to key ground. This will smooth out the signal presented to the analog input. The best value would depend on the resistance in the ladder itself, so all you can do is try some values to see if something helps. I would start with something like a .1uF or .22uF bypass cap just because they are fast and cheap. If the value is too small it will not help, & if too large the key response time may become slow. You may also have to "teach" your HU the new key values again. Might be worth a try anyway.

m00n61 said:
Check the mtc-status bar module in xposed (and mtc-statusbar.ini). It could be disabled
Click to expand...
Click to collapse
I've checked the mtc-statusbar.ini, there is no mention of this function. I'll try asking over at Malaysk's thread, but I'm afraid he might not be able to help much as well since he doesn't have a 1024x600 unit and he announced that he will be retiring.
m00n61 said:
No idea. Apart from app configuration settings - night mode may be disabled.
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Click to collapse
Night mode is set to auto in the navigation apps. However, they do not switch to night mode at all. Manually setting them to night mode works, but the maps become too dark for use during the day.
dhmsjs said:
From what I have seen of the MCU code itself, I don't think that Key2 is meant to be a ground reference for Key1. They are both handled the same way in the code -- as separate analog inputs. When they change and become stable, the MCU sends a message to the Android cpu. So if Key2 is being used as a reference it has to be happening on the Android side of things. Looks to me far more likely that Key2 is just used for cars with more than one resistive ladder.
If your SWC keys work but are sometimes unreliable, you might try placing a small bypass capacitor across key1 to key ground. This will smooth out the signal presented to the analog input. The best value would depend on the resistance in the ladder itself, so all you can do is try some values to see if something helps. I would start with something like a .1uF or .22uF bypass cap just because they are fast and cheap. If the value is too small it will not help, & if too large the key response time may become slow. You may also have to "teach" your HU the new key values again. Might be worth a try anyway.
Click to expand...
Click to collapse
Thanks for the suggestion. Based on what I've found, the ladder for my car looks something like this:
No buttons pressed: Approx. 4.7k ohms
Mute: Approx 22 ohms
Vol+: Approx 90 ohms
Vol-: Approx 200 ohms
Mode: Approx 360 ohms
Seek >: Approx 690 ohms
Seek <: Approx 1.5k ohms
My colleague has suggested that perhaps 22 ohms is too little for the unit to sense properly and adding a resister of say 500 ohms to Key1 may solve the issue.

firefly_hm said:
Based on what I've found, the ladder for my car looks something like this:
No buttons pressed: Approx. 4.7k ohms
Mute: Approx 22 ohms
Vol+: Approx 90 ohms
Vol-: Approx 200 ohms
Mode: Approx 360 ohms
Seek >: Approx 690 ohms
Seek <: Approx 1.5k ohms
My colleague has suggested that perhaps 22 ohms is too little for the unit to sense properly and adding a resister of say 500 ohms to Key1 may solve the issue.
Click to expand...
Click to collapse
firefly_hm said:
I've look through the service manual, the SWC controls are connected to the CAN communication system, but I'm not sure how this works. Will research this further, thanks.
Click to expand...
Click to collapse
If your SWC is through CAN BUS then it is not a resistive ladder.
Maybe you should start here to understand how this works.

m00n61 said:
If your SWC is through CAN BUS then it is not a resistive ladder.
Maybe you should start here to understand how this works.
Click to expand...
Click to collapse
This is the diagram that is shown in the service manual for my car. As you can see, it is a resistive latter, and it is also connected to CAN:
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firefly_hm said:
This is the diagram that is shown in the service manual for my car. As you can see, it is a resistive latter, and it is also connected to CAN:
Click to expand...
Click to collapse
The fact that both the SWC wires and the CAN BUS module connect to the audio board doesn't mean SWC is connected to CAN BUS. Anyway, have fun with your unit.

firefly_hm said:
...Thanks for the suggestion. Based on what I've found, the ladder for my car looks something like this:
No buttons pressed: Approx. 4.7k ohms
Mute: Approx 22 ohms
Vol+: Approx 90 ohms
Vol-: Approx 200 ohms
Mode: Approx 360 ohms
Seek >: Approx 690 ohms
Seek <: Approx 1.5k ohms
My colleague has suggested that perhaps 22 ohms is too little for the unit to sense properly and adding a resister of say 500 ohms to Key1 may solve the issue.
Click to expand...
Click to collapse
Here are some more details about the SWC algorithm that may help your colleague. This is based on what I see in the MTCB-KLD2-V2.77 MCU, but is also true in MTCC-KLD6-V2.91 as far as I have seen, so I suspect it is common to most MTCB & MTCC MCUs.
The MTCD MCU is a different processor altogether so this does not necessarily apply to those.
The A to D converter is 10 bits with a voltage range of 0 to 3.3v. Conversions are triggered every 1.1 mSec and each conversion takes about 49uSec. To accommodate a wide range of ladder impedance, the MCU sequentially applies 3 different bias currents to the ladder and reads the voltage present with each one. It adds the 3 readings together to form a composite value. Three of these composite readings are averaged together to form the final value, and to detect stability of the signal. The 3 bias levels are
With key bias 1 and 2 both off:
Key 1 input pulled up to 3.3v with 22k
Key 2 input pulled up to 3.3v with 22k
With key bias 1 on:
Add 2.2k pullup to Key 1 input
Add 2.2k pullup to Key 2 input
With key bias 2 on:
Add 470 ohm pullup to key 1 input
Add 470 ohm pullup to key 2 input

Dasaita Head Unit just died ?

Hi everyone,
I have ordered almost 2 years ago a Dasaita 9" Android 10 Head Unit (4G 64G Octa Core) for my 2009 Forester. Until yesterday the device worked fine, I really loved and enjoyed it, I was really impressed with it. The only thing I change I was the launcher and mainly used it for Google Maps, Spotify and Torque Pro.
Yesterday on my way to my mate’s, 50km on the way, the head unit just stopped working, I was just using google maps and listening some tunes on Spotify. (note: the screen was hot to the touch).
Since then the screen is totally black and the only thing that lights up when I turn on the lights are the side buttons. I tried to reset, the lights are flashing then nothing. No matter what the screen remains dead. Also I noticed my OBD2 adapter doesn’t connect automatically to the HU as it used to and I can’t connect by Bluetooth with my phone neither.
All this brings me to think that the HU is dead ????
I saw few videos and threads online with people having more or less the same issue… anyone got a solution or faced the same problem ?
Thank you for the help

What steps have been taken to investigate

MrPoopyButtOle said:
Hi everyone,
I have ordered almost 2 years ago a Dasaita 9" Android 10 Head Unit (4G 64G Octa Core) for my 2009 Forester. Until yesterday the device worked fine, I really loved and enjoyed it, I was really impressed with it. The only thing I change I was the launcher and mainly used it for Google Maps, Spotify and Torque Pro.
Yesterday on my way to my mate’s, 50km on the way, the head unit just stopped working, I was just using google maps and listening some tunes on Spotify. (note: the screen was hot to the touch).
Since then the screen is totally black and the only thing that lights up when I turn on the lights are the side buttons. I tried to reset, the lights are flashing then nothing. No matter what the screen remains dead. Also I noticed my OBD2 adapter doesn’t connect automatically to the HU as it used to and I can’t connect by Bluetooth with my phone neither.
All this brings me to think that the HU is dead ????
I saw few videos and threads online with people having more or less the same issue… anyone got a solution or faced the same problem ?
Thank you for the help
Click to expand...
Click to collapse
I'd pull the unit and check you didn't just lose you 12v or ground cable.

gottahavit said:
I'd pull the unit and check you didn't just lose you 12v or ground cable.
Click to expand...
Click to collapse
Thank you for your answers.
So I have pulled the unit out and checked with the multimeter, I’ve got a good ground and I read 12V (from the harness adapter). These seems fine right ?!

I assume you've tried the reset button?
Does the Daisata have a detachable screen? On my joying I'd check the ribbon cable.
Next I'd attach the 12v and ground to an external source(got a battery charger around?)
If that all fails then I guess try to talk to the Seller.

gottahavit said:
I assume you've tried the reset button?
Does the Daisata have a detachable screen? On my joying I'd check the ribbon cable.
Next I'd attach the 12v and ground to an external source(got a battery charger around?)
If that all fails then I guess try to talk to the Seller.
Click to expand...
Click to collapse
The screen isn’t detachable.
I got in touch with the seller and that’s his reply:
“1. Do you try to power off the device to check?
2. If you have power off and it still doesn\'t help. Please remove the power cable and then wait 3 minutes to plug it again.
3. After plug the power cable, wait 3 minutes, and then click the touch screen button to check whether you can hear the sound.
4. If you can hear the sound, you can check the 2 bands in the following:
https://image.pushauction.com/0/0/dce5012a-1758-4291-8a6d-52d646eb6789/d770b77d-524c-47b5-8e88-6454abf03318.jpg
Here is the video for you to check how to unplug one band:
you can follow it to check another bands.
5. If the step 4 don't help, you can check the unplug the core chip, and then plug it aigan:
6. If the step 5 don\'t help, please use the pin to press the RST after you reconnect the power cable. You should press the RST hole until you saw the button light is flashing
to check whether you can see the image now.”
I’ve followed the steps 1 to 3 and nothing happened, no sounds.
just got back from work and I’m gonna give a shot to no4, unplug the chip…

I would press the reset pin as the first step, but as long as they are helping you through it.

If the unit has HDMI output, I would suggest hooking up an external monitor. If you see a valid image on the external monitor, then most likely the problem is the LCD display in the head unit. If nothing is displayed on the external then it's likely the core board or some part of the mainboard which may have overheated. These units have many weak points that can render them useless.
I will share with you that I had this exact same unit as yours and the TFT board (it's the board that interfaces the LCD display to the mainboard) had a component burn up which left the screen dark. Dasaita provided a new TFT board which got the display working again. If you do manage to get the unit going again, never run the display brightness at 100% or you risk having the TFT board problem.

Requested moderator to move this thread to MTCD Android Head Units General.

jlbooth said:
If the unit has HDMI output, I would suggest hooking up an external monitor. If you see a valid image on the external monitor, then most likely the problem is the LCD display in the head unit. If nothing is displayed on the external then it's likely the core board or some part of the mainboard which may have overheated. These units have many weak points that can render them useless.
I will share with you that I had this exact same unit as yours and the TFT board (it's the board that interfaces the LCD display to the mainboard) had a component burn up which left the screen dark. Dasaita provided a new TFT board which got the display working again. If you do manage to get the unit going again, never run the display brightness at 100% or you risk having the TFT board problem.
Click to expand...
Click to collapse
There isn’t a HDMI output, is there another way I could hook it up to a monitor ???
It’s interesting what you’re saying about the brightness, I often had it on max during the day and my partner who had the car on the day the unit died told me that she had the car heaters on ( it’s cold in the part of Australia where we at) and noticed that just before dying the screen brightness went dim.
it’s really confusing right now as I can’t figure out what exactly is the problem.
I tried everything the seller suggested and nothing worked. How long did your unit last ? I’m just wondering if I should just get a new one but it is annoying as I only had it for 2 years and I got the top of the range (at the time) from them.
Thank you

Only other option I can think of is that there may be composite video out connections via RCA connections if it has those. Since you say it does not connect to your phone via Bluetooth, that suggests the unit is not booting up when power removed and reconnected. I would venture a guess that the coreboard has an issue especially if the problem was caused by a thermal issue. But that's only an inconclusive guess on my part.
Even when the screen was an issue the unit would boot up and it connected with my phone.
My unit lasted about 5 months before the screen problem. However it was in my second vehicle and it wasn't my daily driver, thus it probably wouldn't have lasted that long if it was being used everyday. Fortunately in my case Dasaita provided the needed replacement board at no charge under warranty.

MrPoopyButtOle said:
The screen isn’t detachable.
I got in touch with the seller and that’s his reply:
“1. Do you try to power off the device to check?
2. If you have power off and it still doesn\'t help. Please remove the power cable and then wait 3 minutes to plug it again.
3. After plug the power cable, wait 3 minutes, and then click the touch screen button to check whether you can hear the sound.
4. If you can hear the sound, you can check the 2 bands in the following:
https://image.pushauction.com/0/0/dce5012a-1758-4291-8a6d-52d646eb6789/d770b77d-524c-47b5-8e88-6454abf03318.jpg
Here is the video for you to check how to unplug one band:
you can follow it to check another bands.
5. If the step 4 don't help, you can check the unplug the core chip, and then plug it aigan:
6. If the step 5 don\'t help, please use the pin to press the RST after you reconnect the power cable. You should press the RST hole until you saw the button light is flashing
to check whether you can see the image now.”
I’ve followed the steps 1 to 3 and nothing happened, no sounds.
just got back from work and I’m gonna give a shot to no4, unplug the chip…
Click to expand...
Click to collapse
From my teardowns of my MAX10 unit (Toyota Universal + PX6 + Car Play), you have a little driver board behind the screen. It isn't the same as the picture you sent as mine is a universal type unit. On yours all the buttons are off the big pcb board and the driver board is soldered onto that (so not physically removable without some soldering). But if the buttons light up then your unit is turning on somewhat. So what I can see from step 4: #2 is the ribbon connecting the screen driver board to the mainboard; #3 is ribbon connector for the lcd display panel, #1 is your CPU board. There's a photo translator app on google play if you want to give that a try with the labels in Chinese.
Best of luck with this mate. The HDMI out is a mini HDMI connector on the CPU board - see if you can get that to display something on a spare screen (on later units they just have a cable to that directly and they sell it off as having hdmi out). If it doesn't output anything then your CPU is potentially dead at this point. There is an STM32 microcontroller (i.e. the MCU) on the amp board and that can be powering up the button lights.

That "driver board" that @nxdesign refers to is the TFT board that Dasaita provided a replacement when my unit died. I could tell that my particular unit was at least booting up as I could see that it was pairing with bluetooth on my phone. I tend to believe OP's problem is either CPU or MCU failure - perhaps thermal related. These units don't provide adequate cooling.

You're welcome to send it to me in NZ, I often get SOMs sent to me for repair and would be happy to look at your unit. Failing that, suggest warranty.

nxdesign said:
From my teardowns of my MAX10 unit (Toyota Universal + PX6 + Car Play), you have a little driver board behind the screen. It isn't the same as the picture you sent as mine is a universal type unit. On yours all the buttons are off the big pcb board and the driver board is soldered onto that (so not physically removable without some soldering). But if the buttons light up then your unit is turning on somewhat. So what I can see from step 4: #2 is the ribbon connecting the screen driver board to the mainboard; #3 is ribbon connector for the lcd display panel, #1 is your CPU board. There's a photo translator app on google play if you want to give that a try with the labels in Chinese.
Best of luck with this mate. The HDMI out is a mini HDMI connector on the CPU board - see if you can get that to display something on a spare screen (on later units they just have a cable to that directly and they sell it off as having hdmi out). If it doesn't output anything then your CPU is potentially dead at this point. There is an STM32 microcontroller (i.e. the MCU) on the amp board and that can be powering up the button lights.
Click to expand...
Click to collapse
Thank you for your help mate !
I couldn’t find this hdmi connector on the board. The seller is telling me it’s probably the core board and said the shipping cost isn’t worth it to send it back to them. Is there a different way to check the display ???

MrPoopyButtOle said:
Thank you for your help mate !
I couldn’t find this hdmi connector on the board. The seller is telling me it’s probably the core board and said the shipping cost isn’t worth it to send it back to them. Is there a different way to check the display ???
Click to expand...
Click to collapse
A dead coreboard will mean you have a shell of a unit. Can they sell you a fresh coreboard? Or even better give you a new unit at a discount? Who knows what else might have been damaged with the heat.

Just an update on this. The unit was sent to me and received today.
The root cause was that the SOM was non-booting. Recovering the SOM via MASKROM has restored the unit.
The SOM has no additional heatsink or cooling, and this may have been a contributing factor.

can u tell me how do u fix it?? i also have same problem....?

Nothing worked after I did everything the merchant suggested. What was the lifespan of your unit? I'm wondering if I should just get a new one, but it's a pain because I just had it for two years and it was the top of the line (at the time).