MFD Replacement?

Hi y'all.

Has anyone ever contemplated replacing the MFD (and most of the center console beneath it)?

My "vision" (blech!) is to do away with everything in that center strip from MFD all the way down to the cassette player. A large-ish screen - at least a 10" tablet display - possibly larger. I want radio and digital music, I'd ditch Toyota Nav for Google Navigate (and Bluetooth tether), I'd do my own info displays. I'd still have a physical hazard flashers button. Everything else can be a soft button.

Any thoughts? Good idea? Bad idea? It would be great if I did x, y or z? Comments please...

 

FYI - my plan is to use one of the numerous SBCs (single board computers) that run Android and then a separate touch screen. The SBC's have a bunch of GPIO (input output pins) which will allow me to interface to the Prius harnesses in a meaningful way. I may also need to have a CAN or LIN interface - but I think those can be fairly easily added as an add-on to the SBC (i.e. a separate PCB with a simple serial interface to the host processor).

Any of the retail tablets have the advantage of being nicely packaged - but the downside of having no useful I/O capability for this sort of project.

Wise words!

 

What, you mean you don't want a picture of the magic smoke rising out of my dashboard?

 

I presume you're an ex-Chrysler guy? I work with a couple of ex-Chrysler guys at the moment.

I used to work for Ford a long time ago.

 

Ah - I thought you were making a reference to the Daimler-Chrysler debacle.

But come on - don't be shy tell us how you really feel. Oh, you did that already...

My friend had a Sprinter - good when it worked expensive when it didn't. Some terrible design flaws in that one as well. If we ruled the world everything would be perfect, right? Where do I sign up for that gig??

 

Hi contraption,

I'm concentrating on making my Prius a plug-in first before I move on to this project. So, I've not made any progress.

Your idea of using IOIO's sounds good but I'm not yet convinced that the project wouldn't be better served by an SBC. I'm not sure how you intend to have IOIOs communicate to the tablet via Bluetooth? Also at $50 a pop they're pretty expensive to use. Have you looked at any of the mesh network devices? There are some low cost ones appearing on Kickstarter. Although a mesh network onboard a Prius makes me a little nervous!

I don't have any documentation about the climate control (CC). Do you know if it's a digital bus from MFD to a CC ECU or whether it's direct actuation from MFD to CC? I'm hoping it's the latter - and if that's the case then it should be pretty easy to reverse engineer... If it's a digital bus then I suspect that it's LIN based and I have a LIN capable dev board which I can hook up and sniff messages with.

I'd be happy to help support and collaborate with you in your quest - but for the moment my PiP project comes first. I have $5K invested in that project so I really need to see it through! I'm in the process of changing jobs - after which I hope to have more time to devote to this stuff.

 

Well I got an SBC for $75ish - interfacing to an LCD touchscreen will be a challenge but should be "doable". I'm not too bothered about making it portable to other hardware right now - and if it's still an Android app then as long as we modularize things appropriately there will still be a lot of carry over.

OK - I just started poking around the service manual and came up with the attached system diagram for their "Multiplex Communication System" (see attached PDF).

There's an A/C ECU sitting on the Mr. BEAN network (ok I added the Mr. part). There's a separate AVC-LAN and a separate CAN bus. All three of these are linked together via the Gateway ECU. So I wonder if there's a path for CAN commands to control stuff on the BEAN network.

An interesting thing to note is that the DLC3 (the OBD2 connector beneath the dash) connects to the "Multiple Network Body ECU" as well as to the Gateway ECU. That makes me think that there are pins within DLC3 which will probably be able to talk to the MNBECU which in turn can send things on to the A/C ECU. Just a hunch.

My guess is that the MFD sits as a node on the AVC-LAN.

OK - a little more poking around and also attached is a system diagram for the A/C system. Cool... (pun most definitely intended!)

(yeah, both PDFs have the same name - but don't let that fool you!)

 

Hardware I'm currently using is a dev board from Atmel:
Atmel Store / Atmel AT32UC3C-EK

And a DuinoMite Mega (this things a bargain!) My Duinomite Mega Canview V4 equivalent Project | PriusChat

p.s. I've never worked with LIN - I think both BEAN and AVC-LAN may be LIN based - I'm not sure...

 

Googling IBus turned up this on AVRFreaks:

"I've been trying to read and write to the BMW ibus, which is Real Similar to LIN, which is Real Similar to ISO9141. iBus seems to be 9600, even parity, 1 stop bit."​

(good news)

and this:

I did some playing around with iBus in my E39 and E46 some years ago to get my mp3 player info up in the navigation/control LCD display. Worked on one car, not on the other. Although they "should" have the same protocol, they were totally different.
As nothing is documented (available) from BMW, it was all trial and (a lot of) error.
Also, it's difficult to inject messages on the bus without upsetting something else.
It might work on _ONE_ specific car, but don't expect it to work on any other car. Any difference in stereo or car model can **** things up.

Apart from that, you can easily build an interface for it, the net is full of examples. "standard" serial comms.​

(not so good news)

Now, I'm totally distracted again! Gee thanks! ;-) (just kidding of course my ADHD is no concern of yours...)

 

OK - more googling...

AVC-LAN - eLinux.org - seems like it's a differential signal much like CAN (and they talk about using CAN transceivers as a driver). And this one has more details: TOYOTA Corolla MP3 Project. TOYOTA Corolla MP3 Project. SigmaObjects inc.

BEAN Bus - eLinux.org - wheras Mr.Bean is a single wire at 10kbps (hardly any info on that page). And here's an SAE paper (behind paywall): Body Electronics Area Network (BEAN)

So, it looks like there's more opportunity for hacking the AVC-LAN bus than the BEAN bus? (i.e. more info available). It might be time for me to buy a logic analyzer (something like this: Saleae Logic. The logic analyzer you'll love to use.)...

But hang on a sec - I'm not supposed to be doing this yet!

 

Other cheapo logic analyzer choices:
USB Oscilloscope & Logic Analyzer & Signal Generator | eBay

ZeptoProg II AVR ISP Programmer and Multitool (AVRISP mkII compatible)

EZ-USB FX2LP CY7C68013A USB Development Core Board Logic Analyzer EEPROM | eBay

 

Actually I don't think it will be too hard because it's likely that all the commands are pretty much discretely controlled by buttons. Press a button capture the bus traffic. Press another button capture the bus traffic. Repeat a few hundred times and we should have it figured out!

Yeah, I've been wanting one of these for a while. If I remember correctly their software is free so you could use one of those cheapy devices (specifically the one that starts EZ-USB) and probably use that as the hardware and still use the Saleae software. But that would be a little "mean". Plus the Saleae seems really well put together so I'm sure it's worth it.

Yes, all good points. For me the 'droid will also replace the navigation functions.

Sounds good.

Spoil sport! ;-) But you're right. However, one last thing... Check out this link: TOYOTA Corolla MP3 Project (make sure you scroll down to the "simpler version". That's pretty darn straightforward. I think I'll use the source code from that project and make something work on the DuinoMite to sniff AVC-LAN and display on VGA monitor as well as log to SD Card. Is that something you could use? I don't know you're tech background - perhaps something you could whip together yourself?

Anyway, I know, I know back to the other stuff...