How many of you would be interested in a reverse engineered climate control/computer

[MazerRackham]

So I was looking at the computer and climate control and I was very disappointed at how much space they all take separately. I've been thinking of fuzzing, and mapping the input/output for both the OBC and the HVAC control systems and dumping that into a small binary that could be run on like an RPI Zero. Seeing as how a raspberry pi zero is 5 dollars, 1/00th the size, 1/00th the power consumption and probably a 100x more compute power than the stock E36 computer. My main goal would be to consolidate all their functionality. Ideally one would only need to add a small $30 touch screen LCD to the RPI zero to emulate all of the original computers functions with the added bonus that all three functions now only occupy 1 DIN slot in the console area, and the code is portable and able to be used on bigger devices such as a RPI 3 or newer allowing for a open-source infotainment system similar to a Tesla except you can actually fuck with the code.

The biggest benefit of course would be making it so those dated computer units could all be ditched in favor of a 5 dollar computer with a 30 dollar touch screen. No more bulb repair, blown resistors, fuses, LCD repair, calling the dealer for the head-unit lockout code etc... Cheaper, easier, and open source.

If anybody has an extra stock head unit/HVAC control unit/computer (the one below the HVAC) to donate to reverse engineer would be helpful so I don't have to rip mine out in the time being.

[testify]

I'd rather just make it more reliable with levers and knobs.

[MazerRackham]

I'd rather just make it more reliable with levers and knobs.

Not sure if trolling or....

Anyway, if you aren't trolling levers & knobs =/= more reliable. I mean look at the DIY section of this forum. The top posts are replacing the bulbs, fuses, and resistors for those three pieces of hardware. More moving parts = more failure. All the moving parts are eliminated in this system. Well they aren't completely eliminated, they're just turned from physical parts into virtual parts, and of the physical parts they're replaced with readily available and cheap components one can get from amazon in two days or less. And I'd rather write the code to fix a bug and flash it with a USB stick, than have to pull my center console out every time I want to fix something. Also its impossible to "brick" and RPI since all the hardware is open source. Bad flash? Just flash to stock and retry.

[shogun]

Have not had any problem with the existing original unit since I own my E36 M3 since > 7 years, also want to keep it original, therefore no interest in such modification.

[E36328Coupe]

Not sure if trolling or....

Anyway, if you aren't trolling levers & knobs =/= more reliable. I mean look at the DIY section of this forum. The top posts are replacing the bulbs, fuses, and resistors for those three pieces of hardware. More moving parts = more failure. All the moving parts are eliminated in this system. Well they aren't completely eliminated, they're just turned from physical parts into virtual parts, and of the physical parts they're replaced with readily available and cheap components one can get from amazon in two days or less. And I'd rather write the code to fix a bug and flash it with a USB stick, than have to pull my center console out every time I want to fix something. Also its impossible to "brick" and RPI since all the hardware is open source. Bad flash? Just flash to stock and retry.

Bulbs fuses and resistors aren't moving parts. What's more all of those (except bulbs) would have a place in your new solution.

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Have not had any problem with the existing original unit since I own my E36 M3 since > 7 years, also want to keep it original, therefore no interest in such modification.

Yep. Had the same thought when the bulb went again (6 years) in my headlamp switch, I could LED it and it last forever or buy a 10 pack of bulbs and use the time elsewhere, because LEDs don't have the same lighting pattern. Keep It Simple

[vollosso]

I was going to do something like this when i was going to install a car pc and touch screen. Do it. Dont listen to the masses. Gl.


Sent from my iPhone using Tapatalk

[testify]

Not sure if trolling or....

Anyway, if you aren't trolling levers & knobs =/= more reliable. I mean look at the DIY section of this forum. The top posts are replacing the bulbs, fuses, and resistors for those three pieces of hardware. More moving parts = more failure. All the moving parts are eliminated in this system. Well they aren't completely eliminated, they're just turned from physical parts into virtual parts, and of the physical parts they're replaced with readily available and cheap components one can get from amazon in two days or less. And I'd rather write the code to fix a bug and flash it with a USB stick, than have to pull my center console out every time I want to fix something. Also its impossible to "brick" and RPI since all the hardware is open source. Bad flash? Just flash to stock and retry.

I'd like it to still be functional without a power source and after the electronics fail.

That will always be more reliable than electronics.

[ChuckDizzle]

I think overall interest will be based upon a potential price point for the finished product.

[scooper]

I'd like someone to make an aluminum heater core...that's what I want... I like my manual hvac. Have both types now.

[LockDots]

So I was looking at the computer and climate control and I was very disappointed at how they were also intimately linked with the stock head unit. I've been thinking of fuzzing, and mapping the input/output for both the computer and the HVAC control systems and dumping that into a small binary that could be run on like an RPI Zero. Seeing as how a raspberry pi zero is 5 dollars, 1/00th the size, 1/00th the power consumption and probably a 100x more compute power than the stock E36 computer. My main goal is to not need the stock head unit to save/make changes on the computer below the HVAC controls. Ideally one would only need to add a small $30 touch screen LCD to the RPI zero to emulate all of the original computers functions with the added bonus that all three functions now only occupy 1 DIN slot in the console area, and the code is portable and able to be used on bigger devices such as a RPI 3 or newer allowing for a open-source infotainment system similar to a Tesla except you can actually fuck with the code.

The biggest benefit of course would be making it so those dated computer units could all be ditched in favor of a 5 dollar computer with a 30 dollar touch screen. No more bulb repair, blown resistors, fuses, LCD repair, calling the dealer for the head-unit lockout code etc... Cheaper, easier, and open source.

If anybody has an extra stock head unit/HVAC control unit/computer (the one below the HVAC) to donate to reverse engineer would be helpful so I don't have to rip mine out in the time being.

How is the OBC and HVAC linked to the stereo?

[Nanniepoo]

intimately

[LockDots]

intimately

[MazerRackham]

How is the OBC and HVAC linked to the stereo?

Just realized some of the settings I was thinking of, such as switching from C to F, and having the AC OFF when the car is turned on being related to the radio were actually F30 specific. Reading too much about BMWs

[gc325is]

FYI This was a home made media center

https://www.bimmerforums.com/forum/s...tablet+control

[MazerRackham]

FYI This was a home made media center

https://www.bimmerforums.com/forum/s...tablet+control

I am essentially wanting to do the same thing, but much cleaner by porting the stock functions of the OBC and HVAC via a breadboard with some kind of 3D printed connector to accommodate the stock HVAC and OBC harnesses to make it plug and play, and also not hacky. Also, I would rather run straight up Linux. Why run a gimped mobile operating system like Android or iOS in my vehicle? The other nice thing about using an RPI3 is the amount of open hardware available via breakout boards. Want to add RCA preamp? 20 Bucks from adafruit or sparkfun.

If anybody has a source for the stock connectors for the HVAC or OBC that'd be great. I found a website a LONG time ago for my Datsun that had all of the electrical connectors, and they were VERY cheap. It was also JUST the connectors. One still needed a special DSUB crimper, but that's easy.

[gc325is]

So lets think, your project is to spend a few dollars ~100 and a few hours to get a device that controls the temperature and air flow in the BMW. And the interface will be smaller and probably harder to adjust than OEM.

I hope you have a digital control now because converting the manual one is probably not possible with simple electronics.
The digital control box is actually small and the heater box has additional control functions, but the interface to you is made large for easy use while driving see below. only a few inch deep and It not linked to the "computer"

If yours was broken and you wanted to install 7" media system and temp control ... this might be something other would like.

But losing the glass holder bin is no big deal.

[MazerRackham]

So lets think, your project is to spend a few dollars ~100 and a few hours to get a device that controls the temperature and air flow in the BMW. And the interface will be smaller and probably harder to adjust than OEM.

I hope you have a digital control now because converting the manual one is probably not possible with simple electronics.
The digital control box is actually small and the heater box has additional control functions, but the interface to you is made large for easy use while driving see below. only a few inch deep and It not linked to the "computer"

If yours was broken and you wanted to install 7" media system and temp control ... this might be something other would like.

But losing the glass holder bin is no big deal.

I wasn't aware that there were "manual" heater controls for the E36? My heater controls are "digital" and looks exactly like the one you have pictured. As far as the actual work reproducing or replacing the heater box itself. I know that it provides power to the HVAC fan which means many amps of power, mosfets, and fuses, which I would not trying to be replicate. Instead it would simply be the button interface that still plugs into the housing which provides all of those functions.

[E36328Coupe]

I wasn't aware that there were "manual" heater controls for the E36?

There are two non-digital versions.

Basic heater - this is conventional manual controls EXCEPT for the heater valve which is electric.
Dual Zone with Aircon and knobs on - this is conventional manual controls EXCEPT for the heater valves which are electric and this is dual zone. This also samples cabin tempt so is thermostatically regulated unlike the one above.

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The only common defect for these is the heater valve sticking which you would be reusing anyway

[MazerRackham]

There are two non-digital versions.

Basic heater - this is conventional manual controls EXCEPT for the heater valve which is electric.
Dual Zone with Aircon and knobs on - this is conventional manual controls EXCEPT for the heater valves which are electric and this is dual zone. This also samples cabin tempt so is thermostatically regulated unlike the one above.

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The only common defect for these is the heater valve sticking which you would be reusing anyway

Thanks for the insight. I had no idea there was that much variation. Definitely deflates my hopes as I would like to provide a comprehensive solution for everyone.

[E36328Coupe]

Thanks for the insight. I had no idea there was that much variation. Definitely deflates my hopes as I would like to provide a comprehensive solution for everyone.

I have the dual zone aircon analogue with knobs system in the 328 and the analogue single zone basic in the 325. While dual zone is thermostatic and you can speak to it with INPA the basic one is not and I suspect the knob for temp is little more than a variable resistor.

With the duel zone analogue you can speak to it with INPA and program with NCS so I expect the activate functions in INPA could be used to control it over the data bus

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The feet or vent or windscreen onboth these would need a stepper motor adding as driven mechanically by hand

[gc325is]

Manual version is harder to computerize

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not as complex as the digital one

here is a peak inside
http://users.sdsc.edu/~jrowley/bmwfix/bmwfix.html
http://www.pelicanparts.com/BMW/tech...rol-repair.htm