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HowTo Tesle - Tapping In to the eMMC

8310 Views 7 Replies 4 Participants Last post by  Martii
HowTo Tesla - Tapping In to the eMMC

So, I am now locked out of my CID, and all streaming radio is just static as are turn signals and all bongs. I thought Tesla had done it. But someone who would know told me they had never heard of Tesla doing this, and that it's more likely that Ingineer (Phil) has done this to me. It's a serious problem.

Ok so I appealed for help from some old friends: ce2078, verygreen, and appleguru. We used to share information. But for some reason each in his turn has gone into radio silence.

None will help me with this. No idea why. I am alone.

I notice that even with my repeated encouragement none of them has posted any sort of howto like the ones I've posted here. So it seems that this is what we are doing -- not helping anyone.

As a result I've taken down my howtos. I'm sorry about this but there is some kind of political problem which I don't understand.

Of course this action will not make any of them more likely to help me, I am sure quite the opposite. (Nonsensically) But at this point I have nothing to lose. Why should I help others when NO ONE will help me in an emergency? Life in the Big City.

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Re: HowTo Tesla - Tapping In to the eMMC

So I did exactly as you say below - I have regulated power up to 0.01V precision - 20A power.

I can see board draws almost 5W but allsocket led turns blue for about 5-6 seconds and then goes off.

I've triple checked cables with multi-meter. No shorts. Still no go.

My prior post is the way to fix this problem of the eMMC chip 'wearing out' with age. In early years Tesla did extensive logging which writes to /var in this chip. This Hynix chip is not very good quality, and anyway chips not labeled 'endurance' or similar can't take too much writing.

The result is at some point, now affecting cars 2014 and older, the eMMC will wear out, the Tegra processor will not be able to boot, and your MCU screen will be black. This is inevitable, if one of these commercial rooters has not disabled logging. Most ppl have their MCU replaced and reprogrammed, but all that needs done is the chip replaced. I believe I'm the first to suss this out two years ago.

Myself, I replaced the 8GB Hynix with an industrial-grade SwissBit chip as I'd detailed before.

So doing the rework to remove and replace this chip is risky. And once the MCU is dead it is not very likely you'll be able to recover the /var partition, which is partition 3 on the chip. You might like to get a dump of the chip before it fails so here is a less risky way to do that.

MMC/SD is actually an interface standard which allows different manufacturers to make chips that are drop-in replacements. If you don't want to replace the chip for now and just dump it, you can solder fine wires onto the right pads on the back of the CID, connect those to the AllSocket's header pins, and read the eMMC that way.

This isn't one of those easy things to do. It's not for shoe salesmen. Worthwhile things are rarely easy. But if you've a steady hand and an accurate mind, you'll be fine.

Two caveats:
- This is very fine work and you should use a PCB microscope to do the work. If there's a Maker's Lab near you they may well have an electronics workstation with a scope like mine does. Alternatively you may get by with a pair of Coil high magnification glasses.
- You need a controllable 3 volt regulated DC power supply. Keep the voltage supplied to exactly 2.8v or else you'll wake up the Tegra which will cause all kinds of havoc. Some Tegras wake up at just above 2.8v, so it's important to use a regulated power supply (as opposed to a cheapie or wall-wart), which can supply at least 5A.

So assuming you've made it this far, here's what my early effort looks like:

What are the connections? (credit: CE2078)

Connect these wires to the correct header pins on the AllSocket, tune the voltage, and plug it into your machine. Use my instructions from the prior post for dumping the images. Likely you'll only get 1bit mode to work, and it will take a good while.

Next time: Modifying your image to get root and other convenient modifications.
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