Hello,
I have Galaxy S-IV i9500 which has numerous sensors, which I am sure may be there in other high-end phones of the leading brands.
I usually play around with electronics (even though a total novice) and at times need to know the amount of current actually flowing through the wire, for example when we connect any power charger (laptop,mobile) to the device, then what is the actual current amperage the device is consuming and the charger is able to provide.
The multimeter (analog or digital) is able to measure the AC/DC voltage but not the current. For the current the technicians usually use a handheld clamp meter , which is hooked on to the wire and for a running device
Although i dont know much about the way a clamp meter is supposed to measure flowing current amperes , I assume it has to do with the circular magnetic field (flux) around the wire which is created in the direction of the current (thumbs law or something).
Looking at the Magnetic Flux sensor in S4, i have see that it responds to magentic flux created around charging objects. For example (using any sensor reading app) I can see that the magetic sensor reading fluctuates when the mobile is brought near to an active on object like a mobile or laptop charger. You can see and experiment yourself.
So just suggesting that can we make an app to use this sensor , get the magnetic field reading and maybe based on the priciples of a clamp meter can measure the amperes passing though any live wire. It doesnt have to be dead exact, a near estimate can suffice initially..
Was a wild thought by a long shot anyways, tell me to go smash my head and read about basic electronics first before giving stupid ideas.
Thanks for reading anyways.
In some cars, such as mine, when I start the engine, ACC power is cut to the HU. So, if I am sitting in the car with the HU on and engine off, when I then start the engine, power is briefly interrupted to the HU. Sometimes this can cause issues with Android. It can also restart the boot sequence if the HU hadn't fully booted. So I have been considering this mod...
dsa8310 said:
Since the ignition wire gives a very weak signal to the HU, using a diode and a capacitor at the ignition entry of the HU should prevent the reset without any Xposed based module.
It works for my mirror with compass.
(the diode has one end connected to the ignition wire; the capacitor has one end connected to ground; the other two ends are connected to the ignition entry of the HU - the red wire(?))
Just use a so called solid/polymer capacitor (not with liquid electrolyte!) which works below freezing temperatures - or otherwise rated up to -40 degrees Celsius.
Code:
HU IGN
IGN o-------i>|-------X------i]-------o GND
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dsa8310 said:
Any (Sillicium) diode would do, finding the appropriate capacitor value, only by testing. If it's too big, then the normal powering off is delayed objectionably, while if too small, it won't delay enough (to cover for those few seconds while the engine starter is working). You would also need a capacitor that still works at below freezing temperatures (solid, tantalum).
Just connect the diode between your ACC/IGN car (or CAN bus adapter) wire and the HU IGN entry, and the capacitor between the same HU entry and ground.
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clearchris said:
I reccommend against tantalum caps unless you really know what you are doing as tantalum caps failure mode is flames. :fingers-crossed:
Solid polymer organic caps, though harder to find, or low temp rated electrolytics (they exist) are what i would go with.
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dsa8310 said:
Read my lips:
Connect a diode (Si) between the car's ACC wire and the HU's ACC entry. If the HU does not start then reverse the diode.
Connect a capacitor between the HU's ACC entry and ground. Choose a capacitor able to function below freezing temperatures. If capacitance is too big, the HU will remain on too long after stopping the car engine. Conversely, if it's too small, the starter will reset the HU as before. Start with a 100uF capacitor and find the optimal value for your car.
If unhappy with this hardware solution, delve into the Xposed framework based software solutions (mtc... xposed... something).
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680uF & 1,000uF capacitors have been suggested.
But then I saw mention of some prebuilt timer PCBs and there were some links to listings on eBay USA. Has anyone got any links to tried and tested devices sold through UK based sellers that are relatively simple for a non-electronics expert to configure?
What are your exact problems with your HU?
I had the same issues with those cheap USB plugs for the cigarette lighter.
5V output is not stable during power on, the connected usb harddrive does a reset.
I took a look at the switched 12V supply. In my case when powering on the switched power supply is pulled down to 0V for about 2seconds.
That's nothing you can solve with a capacitor. Step 1 was to use a diode with resitor capacitor combination to switch a relay.
Step 2 was to use a different 5V supply which is stable down to 6V.
It's not a major problem. I just don't like power being interrupted when starting the engine. This can interrupt the boot process, causing a slight delay. It can also cause an error message when booted, some sort of system app / service doesn't like it. Also, I don't think it's good for device longevity having its power suddenly cut and reapplied in quick succession. So I wanna fit a capacitor to keep the ACC power live to the HU when starting the engine.
I'm looking at electrolytic capacitors on eBay and it seems like a mission getting a 12v capacitor. Would a 10v or 16v capacitor work? Which would be best?
CARRisma said:
I'm looking at electrolytic capacitors on eBay and it seems like a mission getting a 12v capacitor. Would a 10v or 16v capacitor work? Which would be best?
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Hi CARRisma, just use a capacitor rated above 12v, 16v would be fine, keep in mind that xxV referes to the maximun volta. the capacitor can handle, the other value ( µF, F...) is the "charge" it can hold. Very important, if you use electrolytic capacitor pay attention to the polarity (- to GND and + to POSITIVE), otherwhise it could EXPLODE
A picture (video) is worth a thousand words
https://www.youtube.com/watch?v=-KX5HIE7Ddk
I'm going to have to do this too. Every time I start my car w/ the unit already booted up it starts to shut down and it says exchange service has crashed or something similar. Are you just using one cap and without a diode? Could you tell me what you go with?
Dave
Yes, that's the problem I have, some sort of Google service crashes. I plan to use a diode too.
CARRisma said:
I'm looking at electrolytic capacitors on eBay and it seems like a mission getting a 12v capacitor. Would a 10v or 16v capacitor work? Which would be best?
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You don't want a 12 v one - "12 volts" in a car is actually closer to 13.5 v. I'd get a 25 v one. You can use one which is rated for more voltage within reason (e.g. don't go for a 250 v one), it's just that as the voltage rating increases so does the size and cost.
so are you guys going to use a 1 Farad 16v cap? Unless my math is wrong but that is HUGE.
Dave
Pass, I haven't got that far yet and electronics isn't my strong point.
Or based on size constraints i'm thinking maybe wiring three 5.5V 1.5F in series to get me to about 16.5V .5F. That'd give me about a second and a half of capacity down to 10V. You guys think that'd be acceptable for this instance?
Maybe try one of these:
http://www.amazon.com/gp/product/B00PD65UGA
http://www.3rdbrakeflasher.com/timer-c-68/multifunctional-3v24v-time-delay-relay-timer-p-192.html
That will work for the times when I start the car right away but for the times the accessory is turned on then the car is started it wouldn't. I just need to retain 10-13Vdc for a few seconds while cranking voltage dips.
Dave
For packaging reasons I think I may go with this instead. Three of these will put me at 16.2V and 1.68F and I'd have ~5 seconds of runtime in a manageable package about 1.25" square. Problem is I have to buy 100 of these things although their 100qty is cheaper than most 5qty. Opinions?
Or maybe these as they're a bit cheaper and smaller
TT_Vert said:
That will work for the times when I start the car right away but for the times the accessory is turned on then the car is started it wouldn't. I just need to retain 10-13Vdc for a few seconds while cranking voltage dips.
Dave
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Is that a response to the timing I posted? If so this timer is programmable so if you want it to smooth out a drop in acc it will do that. You simply set its delay longer that you expect the drop for the cranking. Obviously, you can also use it for longer delays if you want your unit to be powered for a period of time after you turn off the car. Both short and long delays will smooth out your issue.
I can't always predect the delay between acc on and crank to be honest. With that I just checked w/ my DVOM and the acc. goes dead on crank so that is my culprit, not so much a minor voltage drop but a complete drop.
The ignition wire is only a signal, power is drawn from a different wire. Maybe a couple of mA? So, a few mF might do.
You're right. I thought it was more than a signal. it is only drawing 1ma. Excellent, looks like a 35v 1000μF should do nicely.
TT_Vert said:
I can't always predect the delay between acc on and crank to be honest. With that I just checked w/ my DVOM and the acc. goes dead on crank so that is my culprit, not so much a minor voltage drop but a complete drop.
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I think perhaps you misunderstand how this works. If you configure the timer delay for 30 seconds it solves your problem. If you configure it for 10 seconds it probably solves your problem. You don't need to know specifically how long because if you set it at something like 30 and your cranking lasts 3 seconds it still works because the cut of acc triggers the timer and the power stays on for 30 seconds. 3 seconds later the power turns on and the timer stops because you have power again.
Thanks, I'll look further into this.
Dave
Went ahead and used a 470μF cap today w/ a 1A rectifier diode and it works great. W/O the diode i only got about 1/2 a second of capacity. with the diode I get over 7 seconds. It seems the HU will stay on when the acc. is all the way down to ~6.5v which surprised me.
Hi everyone,
I have a bricked K1 Plus box that apparently has some hardware damage to the eMMC power supply.
Via UART I am only getting
Code:
GXBB:BL1:08dafd:0a8993;FEAT:EDFC318C;POC:3;RCY:0;EMMC:800;NAND:81;SD:800;USB:8;GXBB:Fixed PLL lock failed
BL1:08dafd:0a8993;FEAT:EDFC318C;POC:3;RCY:0;EMMC:800;NAND:81;SD:800;USB:8;LOOP:1;EMMC:800;NAND:81;SD:800;USB:8;LOOP:2;EMMC:400;NAND:81;SD:800;USB:8;LOOP:3;EMMC:800;NAND:81;SD:800;USB:8;
Looking at the board, there is a S47BAB SOT23-6 power regulator and a A19T that are getting very hot immediately after power is plugged in.
// great, wasted time creating and uploading pictures of PCB but cannot include them as a new user... couldn't vBulletin tell me when clicking the "insert image" button?
In any case, it's about 1U4 and 1Q3.
A19T is an AO3401 p-Channel MOSFET,
Pin 2 (Source) of A19T goes to Pin 6 (Output?) of the S47BAB regulator, which I could not find any information about.
So I think the regulator itself might still be fine, but it has way too much load attached...
It seems to be the power supply for the eMMC module, does anyone have the schematic for K1 Plus to verify that?
Could someone measure the correct voltage at that regulator / MOSFET, I think it should be either 1.8V or 3.3V for the eMMC?
I'm currently waiting for replacement AO3401 to arrive, however I still wonder how this could draw so much current? (when the MOSFET burns up shouldn't it be either permanently conductive or non-conductive?)
The eMMC itself is not getting any hot, the only other part that is getting slightly warm is the regulator 1U1 and some resistors near the S905 XTAL, but that is probably normal).
Next thing I would try to desolder the MOSFET and see if S905 can boot from USB or microSD. "PLL lock failed" might be just due to some overload of the power supply I hope?
Any help and ideas are appreciated
I had the same problem, but I resolved using the attached firmware with amlogic burning tool 2.2 and a cable usb with a data port + a power port.
I noted that with a standard usb cable male to male there is not enaugh power.
In this way the burner tool recognize the box and you can flash the firmware
So as others have posted here, I've got serious USB issues for months now. I first thought it's the cold weather, but after a week or three with nice weather above zero all the time, and now even 16C I still have issues. I tried to find the issue today, and removed everything from the radio that could interfere. Nothing at all!
I have a USB hub that I connect with a LED in it that indicates there's power. That LED is always on when I plug it in, so there's power, but the HU detects nothing that I plug in. Not with, or without the hub. Nothing from TPMS or DAB+. The USB Controller app also detects nothing.
Everything is screwed down properly it seems, and giving a push on everything doesn't change anything. I'm on the latest Malysk ROM with the so-called software fix, but that doesn't help either. Also manually executing the fix doesn't help. Even resetting the USB via the app doesn't work anymore.
I'm afraid my USB just completely died on my now. I've tried to reboot a few times, and still nothing.
I really don't want to lose DAB+ and TPMS. That's really useful if you're used to it. Going back to commercials and muddy sounds from FM is such a shame!
Any idea what I can do? I don't think I can replace the USB chip myself without ruining the complete unit. Replace SoM? Replace motherboard? Buy a new unit? Is anyone aware of new units with the proper USB chip? Maybe those PX6 ones?
btw, checked my board and it says HCT-PX5-REV4.0.
And now my sound is completely screwed up as well. Very soft and without bass. As if my amp doesn't really start anymore, anyone an idea which wire to check for that?
To me it sounds as if your MCU does not work properly. I guess that you have a faulty soldering joint. USB devices can draw quite a current from the board. It may be that this caused a soldering joint to crack.
I would go for an optical inspection first. Check if the SOM is plugged in properly and that no capacitors are blown as well.
f465gt said:
To me it sounds as if your MCU does not work properly. I guess that you have a faulty soldering joint. USB devices can draw quite a current from the board. It may be that this caused a soldering joint to crack.
I would go for an optical inspection first. Check if the SOM is plugged in properly and that no capacitors are blown as well.
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Already tried and check that. Nothing weird to see.
But guess what?! It suddenly worked now for 2 days!! Why/how?! It's so unreliable, not sure when it will break again.
It really looks like either temperature or soldering issues. I would go for an optical inspection, just to make sure that no wires are loose or pins are broken.
f465gt said:
It really looks like either temperature or soldering issues. I would go for an optical inspection, just to make sure that no wires are loose or pins are broken.
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Already checked. Nothing weird to see. It has been 10+ degrees for weeks so I doubt it's the temperature.
I don't mean the outside temperatures. The unit heats up while being used. This causes bad soldering joints to get loose. Perhaps it is also a good idea to check the voltage supply. There should be some sort of voltage regulator that heats up. If e. g. the 5V regulator fails, your unit will show such a behaviour. I vaguely can remember that on the S160 units there was sometimes such an issue. Somewhere around here there were some schematics. Search for them.
f465gt said:
I don't mean the outside temperatures. The unit heats up while being used. This causes bad soldering joints to get loose. Perhaps it is also a good idea to check the voltage supply. There should be some sort of voltage regulator that heats up. If e. g. the 5V regulator fails, your unit will show such a behaviour. I vaguely can remember that on the S160 units there was sometimes such an issue. Somewhere around here there were some schematics. Search for them.
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I've got a 12V big fan on top and heatsinks on everything. The CPU never goes above 50C.
But I doubt heat is an issue after a few seconds when the system has booted.
Ah, then the MCU crashed during boot. Does your car interrupt the ACC power while cranking? If so it is a good idea to add a relay box that switches permanent battery voltage over to the ACC line for a few seconds. I am using this one: https://www.amazon.de/Phonocar-Spannungsstabilisator-Fahrzeuge-Start-Automatik/dp/B00AK95QUA
This is an actual relay, not just some diodes and capacitors.
https://www.roadnav.com/forum/knowl...lay-buffer-radio-power-on-during-engine-start
Hello there, I am new to Android and electronics in general, so I hope you can bear me .
So, what happens if I sent a high voltage in Android PCB from an I/O pin directly to the ground pin? Could this damage the board even at 40mA? I understand the output of that pin is from the microprocessor .... but who is in danger here? the microprocessor, the busses or what? I read the basics of microprocessors but I am still confused.
Also, why short circuit is dangerous? Is it because the current is too high and it should be consumed a bit, then travel back to the ground or I got the whole idea wrong.
I don't know... is it designed to be sinked to ground?
Lol, where's the 40 ma figure coming from?
Sounds like you already tried it
If you exceed the specs for voltage or current on a pin you can damage it.