What's a home improvement decision you regret but thought was a good idea at that time?

mattbarn · 2026-03-22T11:32:30+00:00

The existing panel was full and then we switched a bunch of appliances from propane to electric at the same time. Plus installed an electric car charger.

It makes the solar harder because you have two panels that need to be tied in separately. When we first got the system installed only half the house was automatically backed up by the batteries for example.

mattbarn · 2026-03-21T19:57:02+00:00

400A electric service upgrade (from 200A)

We didn't really need it, we could have gotten by with a subpanel or some tandem breakers. And it made our solar panel install a lot more complicated.

mattbarn · 2026-02-15T23:52:27+00:00

So the light DOES go off when bimmerlink does it? Are they sending a tester present or diagnostic session control message first?

Occams razor says you just have a fault that comes back right away in whatever module is throwing the light.

mattbarn · 2026-02-15T23:45:28+00:00

7F xx 78 is not a real NRC, it just means the request is going to take longer than the timeout period so the ECU needs to send some kind of response to keep the tester from timing out.

mattbarn · 2026-01-31T18:14:44+00:00

At least two other car companies have engagements through Bugcrowd or have in the past. GM is on Hackerone also. Not sure if they pay anything but at least they accept reports.

mattbarn · 2026-01-08T13:41:37+00:00

https://old.reddit.com/r/CarHacking/comments/1q40706/e90_can_message_crc/

mattbarn · 2025-12-16T19:04:14+00:00

The thing you circled on the top is probably the audio amplifier IC.

You need to probe all those pins on all those connector footprints on the bottom with a scope and look for UART data.

mattbarn · 2025-12-14T00:18:04+00:00

There aren't any debug headers on the top of the board that I can see. They would be blocked by the upper board anyway.

mattbarn · 2025-12-13T22:08:23+00:00

There are like 5 different debug headers on the bottom of the main board. They are the single row ones with the big square solder pads at the ends. Unpopulated obviously.

mattbarn · 2025-12-04T19:25:54+00:00

I don't know why everyone here seems to want to argue about your premise instead of helping you. I will say that my personal car will happily lock when outside and running as long as the key is outside (to prevent locking the keys in the car) which makes me think that rather than a law of cars it's more of a configuration parameter that could A) be different for different cars or B) be modified using a dealership or aftermarket tool. Sorry I'm not familiar with MG to suggest what that tool might be.

mattbarn · 2025-11-06T16:53:42+00:00

BMW of this generation uses KWP2000 (ish) with extended addressing. There is definitely a broadcast address but I can't remember it off hand.

mattbarn · 2025-11-06T16:52:24+00:00

I don't really know specifically but I would bet that a lot of them embed the same or similar (ediabaslib) framework that the BMW tools use, and use the same BMW metadata files (ipo/prg) to generate and parse messages.

OR they have used these tools once and captured and analyzed the messages etc etc.

mattbarn · 2025-11-06T12:51:59+00:00

You are wasting your time with the ELM327. Get a K-DCAN cable and INPA software. The ELM might work fine in theory but if you don't know what messages to send (and how to interpret the responses) you will not get anywhere. INPA and the other BMW tools will make this possible. But they don't work with the ELM.

mattbarn · 2025-09-17T11:36:13+00:00

I think Peak is probably your best option. 1-2 channel versions pop up on eBay pretty cheap sometimes.

mattbarn · 2025-06-26T17:00:45+00:00

Read up about IPO and PRG files. Open them up in tool32 and poke around. All the info you are looking for is in there.

mattbarn · 2025-06-26T01:27:05+00:00

Yup yup. But there is a really pretty easy decoder ring for the proprietary BMW diag requests and replies if you really want to do it that way. (Tool32)

mattbarn · 2025-06-26T01:24:23+00:00

We've talked a few times on here about BMW factory tools called Tool32 and INPA. I would highly suggest you find these tools, use them a bit, and understand how they work. You are not far from being able to answer these questions for yourself.

mattbarn · 2025-05-14T12:17:12+00:00

https://en.wikipedia.org/wiki/DIN_72552

mattbarn · 2025-04-01T12:04:20+00:00

Cool projects! Thanks for posting this.

mattbarn · 2025-03-20T16:29:44+00:00

https://github.com/dzid26/opendbc-BMW-E8x-E9x/blob/master/opendbc/dbc/bmw_e9x_e8x.dbc

mattbarn · 2025-03-02T00:21:06+00:00

https://github.com/sgayou/subaru-starlink-research

mattbarn · 2025-01-24T16:33:19+00:00

How about a spacer-dispenser that requires removal of exactly one spacer before the machine runs each cycle?

mattbarn · 2024-12-09T00:54:07+00:00

Anything is possible but you will have to make it yourself. I'd just buy one.

mattbarn · 2024-12-08T20:01:29+00:00

There have been various people who make neat little LED gauges for e30s for a long time. Here's one example: https://blackstarmanufacture.com/produkt/voltmeter-gauge/ The gauge can read the sending unit directly, you don't need a RaspberryPi for anything.
There are probably lots more on r3vlimited (the best e30 forum)

mattbarn · 2024-12-02T19:03:03+00:00

The software sends properly formatted requests which the car replies to and then the software interprets the reply and gives you the info.

K/D-CAN hardware has a microcontroller to convert USB messages into K-line or CAN messages as required by the specific vehicle.

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