Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

90's Motorola Cellular radio Emulation

Chrroger

New Member
Guys,
This is inspired by Jeff's mitsubishi cell phone project. I will probably pull a few cues from it. idea is similar.

Preface:
I own a red 1990 Oldsmobile Toronado - Trofeo ( yes its a mouthful!) . The car for its time had EVERY box ticked. leather, remote entry, bose audio, touch screen radio, trip computer and navigation , a COMPLETELY integrated Motorola MX6000 cell phone that can be operated on the screen or by handset.
354055476_10230514817797445_112209551140977968_n.jpg


couple links for reference:
bit of info on the car and VIC system .
( car itself)
( VIC operation)
(early 90s GM prototyping project - I have a garmin unit in progress for mine)


354930941_10230524942210549_5941567066461685262_n.jpg

The touch screen ( called Vehicle Information Center - or VIC as Olds called it) is a joint effort with Sony at the time. its a 6.5" color CRT with its own dedicated computer that also contains the actual diagnostics for car as well . ( GM Mastertech was the dealer tool- the car has it built in to the system already.)


My goal with this system it to get control of the TWO handsets for calls and to add BT music capability with a digital link to the stereo processor. I already have a pile of Sony Mobile ES gear on the shelf to go into the car.

The handsets:
one traditional physical motorola handset - SPECIFICALLY for the car - aftermarket will not work - I tried.
a SOFT handset in the form of the touch screen. this one is network backed along with the stereo and HVAC. GM calls that Entertainment and Convienence bus.

387742404_10231332019626980_8207571348045623273_n.jpg


( put this on a bigger screen as you can probably tell)


I found how to decode GM E&C already. the actual handset is easier, serial data with a master clock.
the cell radio has a hearbeat address. when you pull power on it the soft button goes away and the screen rearranges to suit.


Like Jeff a Wavtek 4300 is also on my list to get list.

as far as the system goes:
Video- already have a unit for that to get a rear camera into the screen. that same unit has a HDMI scaler and a second composite video input. phone will get mirrored there for the audio portion.
363364511_10230836650603064_6049778513140546026_n.jpg
363981893_10230836642682866_6634135789447985578_n.jpg

365429775_10230863451953081_2942083916044146186_n.jpg



Audio side :

Microchip BM83 with an external DAC to allow for SPDIF out
The DAC I am rading docs currently on a ROHM BU9408KS2 , a Microchip item and a TI Burr Brown item. so far the ROHM seems to fit the bill.

in addtion to this I will add the supporting hardware to generate what the original transciever did. intent is to make it plug and go. so pull one unit , plug this in and off it goes.

looking forward to hearing peoples thoughts along the way.
I have been doing video integration for years though this is my first real foray into emulation as such. I have a background in hardware and minor in coding.
 

Attachments

  • 363371789_10230836645122927_6632923243683854386_n.jpg
    363371789_10230836645122927_6632923243683854386_n.jpg
    352 KB · Views: 75
  • motorola - phone pin out - txt.jpg
    motorola - phone pin out - txt.jpg
    72.3 KB · Views: 67
Spoke to RF imaging in Las Vegas earlier today regarding a Wavtek 4300 and antenna.


They had one advertised on Ebay for $300 BUT no antenna. Given one of mine is in the car and the other on a bench I wanted the option of wireless vs having to cable connect to things. Getting to the car one involves ripping out the rear area to get at the radio. not wanting to do that.
 
They had one advertised on Ebay for $300 BUT no antenna.

What kind of antenna do you need? If a small portable antenna like the one on the right side of this picture would be sufficient, then I probably have a spare or two.

IMG_3067.JPG


I used one of these with my mobile service tester for my testing, and it at least gave me a range of a few feet. I think I could have turned the transmitter power level up higher for a bit more range, but I think you'll have to expect to put the mobile service tester in/on/near your car to have it within a few feet of the antenna on the car.
 
that would probably do it ( got email been under 350 tonne cranes for the last week) I am waiting to see if RFimage find one. if not then I will grab one from you.

ideally I would like a 'bit' of range so I can set the thing on a bench outside the car. I grabbed a higher gain 800mhz antenna off a later Caddy about a week ago. the original antenna on mine had seen better days. it also fits the theme of the car.
 
ideally I would like a 'bit' of range so I can set the thing on a bench outside the car. I grabbed a higher gain 800mhz antenna off a later Caddy about a week ago. the original antenna on mine had seen better days. it also fits the theme of the car.

I did some testing instead of relying on 9+ month old memories. With the base station power output turned up to the max of -35 dB, I got full strength signal on the car phone from about 20-25 feet away and was able to simulate incoming/outgoing calls. So I think you'll be fine with setting up on a bench. The range may be further, but that's as far as I could get in my house without going around corners and obstructing line-of-site, which affected the signal strength.
 
Sooo RFimage didn't bother returning a call or an email. bought elsewhere. $119 unit off Ebay is now mine.

going to start laying out the base hardware design in Eagle. managed to find the 32p motorola plug layout and I will have to scrap a cell radio for the plug. this one I will make a socket board for so it is easy to work with.

one change I will make is getting the BT83 on a socket board. Proto Advantage will socket anything you send to them.

working out the 3 power supplies for it as well. +9v,+6v and the 3.3v for all the logic. 9v runs the motorola HS , 6v for the audio drive (LM386)
 
Still waiting for the Wavetek to show up.

question for those smarter than me. anyone played with DSP ICs?

the BM83 has the capacity to drive one and I am seeing a lot of Analog Devices items that look like they may do what I need.

as Stated I want a digital audio out for the music side of this and from the tech data I read I need a device that will handle I2S from the BM 83. I need SPDIF out to feed to the rest of the audio system.

been looking at this one:

https://www.analog.com/media/en/technical-documentation/data-sheets/ADAV4601.pdf
 
RJ50-breakout board.png


quick drawing for a handset breakout board. yes you can buy them but most I found were screw terminals. I wanted pins.
feel free to critique. drawn in eagle 9 for reference.
 
If you only need to convert I2S to S/Pdif then a DIT4096 is probably easier to use?

Re. the PCB - use wide tracks whenever possible, especially for ground or power.

Thin tracks are only needed for either very high frequencies where track widths are critical, or where there is no choice due to space restrictions.

Keep them on the solder side as far as reasonable, for conventional (not surface mount) construction and use a ground plane if you are having the board made by a PCB company rather than etching it yourself. Also try and avoid open "V" junctions, fill the V in somewhat.

You will get used to the methodology as you do more boards.

eg. Just as an example; this also has a topside ground plane:

PCB_Tracks.jpg


(I have been doing them for a while - I used to do artworks for other companies before PCs and sensible price CAD systems were available; hand-taped on layers of graph film, working over a lightbox)

PCB_Taped.jpg
 
Working on the road for a couple weeks so I don't have all my resources of the drawing machine.

regarding the TI piece, I see the I2S but cannot see the SPDIF out on it. Am I missing something here.
KISS is the idea obviously. the AD item I linked above is more of a sledgehammer approach to what I wish to do.
there doesn't seem to be a way on the TI site ( or AD for that matter) to filter down to what has SPDIF and what doesn't.

I remember the carbon transfers well Radio Shack used to sell them and I ( as a kid) would waste my share of them trying to copy layouts from magazines.

Eagle 9 is what I use now and in the case of the one above that was the autorouter function. not a fan of 'Y' junctions either but I cannot find the 'switch' to stop it happening. I usually hit the auto route button then go back over it and redo parts I don't like. that 'y' was one of them.

good point on ground planes. I use them in audio related stuff but for this one I figured it would be ok without as I wanted a break in point to grab data. traces could certainly be bigger. that is one change I will make. the handset supply and ground in the current layout would probably take traces off.
 
regarding the TI piece, I see the I2S but cannot see the SPDIF out on it. Am I missing something here.

It's a dedicated AES-3 (studio standard) converter - but the only practical difference between AES-3 and SPDIF is the signal level.

Just use one of the outputs as a logic-level signal & either attenuate it or feed a TOSLINK optical transmitter.
You could use one output for each, as it's a polarity-independent system.
 
It's a dedicated AES-3 (studio standard) converter - but the only practical difference between AES-3 and SPDIF is the signal level.

Just use one of the outputs as a logic-level signal & either attenuate it or feed a TOSLINK optical transmitter.
You could use one output for each, as it's a polarity-independent system.
AH! ( lightbulb moment!!)

the transmitters I am familiar with. I redesigned an output board on a OE Nissan Clarion 6CD changer a while back so it had optical out ( there was already a Dout pin on it though) to feed a proper car audio DSP. ( common themes with stuff I do as you can tell)

now to fully read and comprehend the sheet for this IC.
 
right..

seasonal break over . I have a few days up my sleeve.

the Wavetek 4305 arrived whilst away. unpacked that last night, plugged it in, booted to main screens then the unit shut down. lights are on , no one is home.
ebay seller yet to respond , USPS looks to have roughed it up a fraction.

going to wait for the Ebay person to say something then tear the top off and work out what died. suspect PSU related as fans come on and the screen backlight still works. would be nice if I had a service manual for the thing.

get that fixed and then start logging data from the unit and the car.

also in the process of swapping over to KICAD. Jeff ( useless pickles) has shown some cool stuff with it and eagle won't do it and they are forcing fusion 360 on me.
 
bit of a delay. ebay seller went quiet on the Wavetek item. I officially have a 35lb+ white box of spare parts.
did find a local ( it is in dallas so I will go pick it up) one . $500 and its almost new. Other Priorities currently so this is on hold for a bit.

Also sourced a few more car specific cell radios as well. the connector is NLA so these are getting scrapped for that item.
 

Latest threads

Back
Top