MMCS television- Anyone got it working?

[Guest]

I like where this thread is heading

 

[SiliconAngel]

LOL I thought you would, Paul

 

[Chris Rogers]

If you did find the equivalent PAL IC then that would be very interesting, i searched hi and low for it and cam up with nothing. This statement puzzels me though : From my memory, and it was a long while ago i looked into this, but the NTSC decoder IC should be all that you need to change within the tuner to get it to work. If you have found the exact PAL counterpart for the original NTSC IC, you should only have to change this part of the tuner to have it work with Australian PAL encoded TV signals (of course there are the accompanying crystals and other external components that will need to be modified to). So i don't know what else about the tuner you are refering to that concerns you?

If your talking about tuning in the correct TV channel frequency then there is nothing to change, as all the 'tuner' part of the TV tuner does is tune in the selected frequency, the decoder IC's do the rest and are the part that doesn't allow the tuner to work here in Australia. So tuning in 209.25MHz (Channel 10 video carrier here in Sydney), is no different to tuning in 209.25MHz in Japan which may be station 'XYZ', its just the decoding that is different.

I havn't looked inside the navi unit, touch screen display or radio unit yet, although i do have a complete set in my garage to play with. The only thing i looked at was the tuner, and i took pictures of all IC's in it so i could try and work out the circuit and what needed to be replaced.

ok you are doing what I am doing with it. I have a compliance shop that is supplying me with cars to modify.

if I found the correct IC then the PN is M52045FP. and the original is ntsc part is TA8819F. I have yet to pop the shielding covers off of the main board (time is killing me.) but I have worked out most of the others.

in regard to the navi - the video is driven by one VERY big asic. probing around with a scope I can find where the video is on it (top right corner with cd drive facing to the left )and but thats it. there are not enough throughboard points to prod the rest of it. just back from there is a HA118104 that is used to switch video for the tv side of things.
my hope is to find a spot on the board and inject RGBs in at that point. still looking for it.

current idea (failing above) is to use a PIC to decode the datastream coming out of the rear of the screen assy for the top left buttom on the screen (internally the button goes high when pushed (no pulse on the signal thank god like nissan does..) and thats it.

I could just be very lazy and hide a switch somewhere but I like integration..

 

[Guest]

Hey Chris while your at it how about getting the GPS working with Australian maps :bigsmile:

 

[Chris Rogers]

no maps for it.. working on something else.

 

[SiliconAngel]

Apparently the Evo X comes with an MMCS system with Australian maps... wonder how different they would be?

 

[Chris Rogers]

quite different. I'm basing that comment on the evo 8 system. had one of those apart already. its worse than this one.


that said:
found this uP in there with a software mask on it..

M380678D191

now if they haven't locked it down then to me its coding.

I haven't gotten that far into it to see if this drives the +30v tuning voltage or not. if I get more time I'll look at it.

to me it would make a lot more sense from a makers point to drive everything via a uP than discrete.
(this thing is starting to look like a xenavi tv box!)

mike,
thoughts?

 

[SiliconAngel]

Chris do you mean µP? And did you mean Mark?

 

[Mrk_VR4]

I took a bit of time today at work to have a quick look at some of the pics i took of the insides of the tuner to refresh my memory of what is going on in there (I'll just tell work its a secret project ). Anyway, as you said the main chip in there is the TA8819F, which is the NTSC processor. Unfortunately the chip the you suggested (M52045FP) is not a direct replacement for the NTSC chip used in the tuner, whilst it essentually performs the same functions its pin configuration is completely different and it is a more compact package. You could maybe get it to work if you made a new circuit for the M52045FP, and could re-map the pins and connect them to the original foot print for the TA8819F, but this would be quite fiddly.

I haven't looked inside the navi unit yet but having a micro in there doesn't supprise me at all. I agree, there is no way they would build a system like this based purely on discrete devices, i wouldn't be surprised to find another micro around the display and/or radio unit. As for the tuning voltage, i'm sure in the TV tuner box somewhere (possibly under the sheilding) would be a PLL sysnthesiser to control the tuning voltage, and the micro would talk to this via an SPI interface most likely. I still don't understand, why do you want to control the tuning voltage?

 

[Hotwire]

Sorry guys, but it has to be done:

Seriously though, I envy your knowledge of this stuff. When I did electrical/electronic engineering I could nevery fully comprehend this stuff. Thus now why I enjoy scoping electrical projects for the Power System (275kV systems) not 0.25V systems LOL

 

[Chris Rogers]

mark,

I'll have more of a dig. NTSC vs PAL B - some of the carriers are in different spots. by this I mean that the tuning voltage will set the freq on these and if its off then its not going to work. colour carrier = 3.58 mhz vs 4.43 for pal - thats a crystal- easy. audio IF - different spot = crystal/resonator - easy.

with the uP - I didnt kknow how to get hte correct character

with the NTSC chip- it would have to sit on a board anyway . thats what I thought when I found it. no other way really.

I popped the top on one of the sheilds last night but didnt get into the tuner side of things properly. I'll tackle this over the next few days when I get a sec.

hotwire,

tech nerd I am. ( did you know its possible to hook up a landline phone is your car and make it work - mine does )

been mucking whith this stuff for years - just happens I like working on automotive stuff more.

 

[Mrk_VR4]

True Chris, i hadn't thought about the video and audio carriers being at different frequencies on PAL Vs NTSC causing a problem, but i don't think it will be. From what i've seen tv tuners have a 250KHz step in their frequency adjustment when tuning, so i would assume this mitsubishi tuner would be the same. From my understanding TV channels are transmitted at a frequency that is divisable by 250KHz, (i.e. video carrier at 191.25MHz or 191.5MHz or 191.75MHz, etc) so assuming the mitsubishi tuner searches with a 250KHz step then you shouldn't have a problem tuning in the desired video carrier. The audio carrier is then at a different spot between PAL (5.5MHz above video carrier) and NSTC (4.5MHz above video carrier), but as you said that can be fixed by changing external components to tune to the right frequency.

If you can find out what frequencies the video carrier of some common japanese tv channels are then you should be able to work out if this will be a problem or not. I would think that it shouldn't be an issue, which will mean a lot less work for you as you won't have to re-program the micro.

 

[Guest]

I too am watching this thread with interest as I retro-fitted an MMCS system and want to get it all working.

This site may be of some use to you guys - The pinout info in particular?

http://mmcs.mylivepage.com/

 

[Chris Rogers]

NTSC FREQs.

PAL FREQs with carrier info.

thats a start.

 

[Chris Rogers]

looking at that its a bit of coding to do it 'properly' and make everything line up. freqs are okayish but some are a bit out.

I'm going to find myself a few chips,crystals,resonators and work out the rest as I go.

I dare say the uP will be a hanging point though. (same as the Xenavi box in the nissan cars.)
We'll see.

 

[Guest]

Was having a fiddle this morning just as a proof of concept, plugged in some rabbit ears and a digital set top box, selected NTSC output and the signal came through fine.

Apparently digital is no good on the move though, but would be OK if you were stopped somewhere on holidays. So if you really must watch live TV then take your STB from home and just get a powered site if at a caravan park. You'll need a good antenna too!

I just had a look on eBay and you can get 12v STBs quite cheap, just do a search for "caravan STB" or "caravan set top box". The one I was looking at was about AUD$50. Make sure you confirm that they have selectable NTSC output before purchasing.

 

[Guest]

Hmm.. on further investigation perhaps you'll need a tuner that accepts the multiple diversity antenna inputs to have any chance of getting an acceptable signal on the move.

 

[Chris Rogers]

yep and a car based one. even then its not perfect.

 

[marc.r]

Yes with an expensive convertor ... not worth it.
Best thing is to get something that has a video out and outputs to NTSC. I bought a Zen Vision M, its a 60GB player that plays divX. Hook that up to the AV channel via the video input on the tunner box in the boot. Then u can watch wat ever u like

is there any other players then a vision M that does this! wow!

 

[Chris Rogers]

western digital do one that takes a USB stick and spits out video. worth a look. I have just put one into a toyota van with decent results.