MFD serial connector?

<div class='quotetop'>QUOTE(topher @ Jan 10 2007, 08:04 PM) [snapback]373955[/snapback]</div>

given your electronics background, here is a rough description of the Prius touch screen protocol, in the interest of giving you an idea of what is involved, so you can make your own decision on which route to go.
The Prius AVC (audio/video) bus connects the MFD, radio/cd and optional NAV and amps by means of a 2 wire differential bus centred on +2.5v with a 250mv differential signal at 41uS per bit. It has the format: long start bit (172uS), 2 byte sender address, 2 byte receiver address, control, length, variable length data field, all with parity. Each message must be acknowledged by the device it is sent to.

When a device which needs to know touch-screen data is active on the bus, the MFD sends out a serial message to that device with X and Y bytes at the end of the message.
The important part is: "a device which needs to know touch screen data must be active". For example, when the NAV is on screen, the NAV needs to know touch screen data and so that data is put out on the AVC bus for the NAV to pick up. If you select any screen other than NAV, those other screens do not need to know touch screen data because they are all internal to the MFD and so get it direct. Consequently, if you look on the bus when these other screens are active, you will find no touch screen data. If you think about it, you wouldn't want the NAV to be accepting touch input when you are actually selecting a CD track. For the 2004/5 Prius CAN-view registers on the bus as a new device that requires touch screen data and thats how I can then convert it to standard PV format serial for jkusnetz & co to feed their car PCs.

The problem here is that even assuming you have NAV when you put video in via a hacked 2006/7 camera input, you are selecting that camera input and not the NAV, so the NAV is not active and the touch screen data is not broadcast. That's rather a fundamental problem. In view of that, my advice (however unpalatable) is that you instead consider buying a motorized LCD like the Lilliput 701 (look under V4 mounting options) where the LCD disappears from view when not in use.) That way you can feed the much better resolution Lilliput directly from your MACmini and also get the touch screen data from it via USB with standard MAC drivers.

I'm clearly not suggesting CAN-view; for this 2006/7 application; it's simply not appropriate, I'm just trying to save you some potential frustration.
good luck!

 

<div class='quotetop'>QUOTE(eflier @ Jan 13 2007, 12:51 PM) [snapback]375231[/snapback]</div>

Did you manage to find some kind of design spec or something?? If so would it be possible to get a link to it?

<div class='quotetop'>QUOTE(eflier @ Jan 13 2007, 12:51 PM) [snapback]375231[/snapback]</div>

Would a XM radio or a factory DVD player count as an external device? I have an ultimate lockpick from coastaletech and the AUX video and audio show up in the MFD as coming from a DVD player.

 

This is a hard under taking, I have been waiting for someone to crack the video. Remember there are 3 parts to this, video, then touch screen, then audio. This was done on the 05 which had an analog screen we have a digital screen much different ball park. We have to figure out all the things for it, there are some ppl getting close but nothing has popped up in recent weeks
here are the forums
http://priuschat.com/My-In-Dash-Car-PC-project-t28275.html
http://priuschat.com/2006-Prius-MFD-GVIF-V...put-t27375.html

There is some code out there from the mac mini using perl to get the touch screens, but remember we would need a way to connect to the screen and get the touches to go to the computer

 

<div class='quotetop'>QUOTE(massimo @ Jul 27 2007, 06:11 PM) [snapback]486484[/snapback]</div>

Well I have a 2005 prius, so already have working analog video and audio.

<div class='quotetop'>QUOTE(massimo @ Jul 27 2007, 06:11 PM) [snapback]486484[/snapback]</div>

It was my understanding that this perl script is just for reading the data coming from a can-view device (which costs $hundreds and does a bunch of stuff I am not really interested in. I don't have a problem writing a touchscreen driver for an xserver, but I just have to figure out a way to get the touchscreen data out of the MFD in the first place.

Actually one of the senior electrical engineers where I work sort of explained how the CAN bus works, and he's saying it would be pretty easy to tap into this stuff, but it might take longer for me to figure it all out since I am a software person.

Basically for at least the touchscreen part of this problem here is what I have gathered needs to happen. We need to have a device on the bus that registers the fact that it requires touchscreen data to be transmitted on the bus. (from eflier) Then we need some kind of can-bus to rs-232 bridge that will allow a normal PC to communicate over the bus (read the touchscreen data), and from that point on it's all just software.

Who knows though, I haven't even started yet, and this could all be way harder than I am envisioning.

 

Just registering myself as another very interested party here. Unfortunately like others I can write software and do the basic hardware stuff but it's a level more advanced than me.

My goals would be to get something that can actually interface to the canview for 2006/7 models, along with other devices like a carputer. It seems to me that coastal or someone else could sell a bunch of 'prius MFD adapter' boxes that would accept incoming video in a couple different forms (RGB and RCA composite for example) and output touchscreen data via serial and/or USB. It seems clear this is possible to build, just a bit beyond most hobbyists. But alas no one has created such a device...