Jump to content

back up camera


handmedownreatta

Recommended Posts

It would be cool if someone could come up with a schematic and the required parts to allow it to display on the 88-89 cars.

On later cars with-out the CD option a display could be mounted in the storage opening in front of the shifter.

Link to post
Share on other sites

The CRT is a VGA computer monitor but operates at a resolution of 320x240, which is a fairly low resolution. I don't know if can display higher than that but as it was purpose built and lacks multi-sync logic circuitry on board, I suspect it's only capable of syncing to that resolution at a specific frequency (possibly 70Hz) and refresh rate. This may or may not be an interlaced video signal, I've not reverse engineered it far enough to say with certainty. To display a composite video signal such as that from a back up camera, you'd need a scan converter that could take a composite video signal, turn it into VGA (and monochrome at that, rather than RGB) at 320x240 at whatever frequency and refresh rate the monitor is expecting and then cut in a electronic video switch of some sort that would maintain sync between the camera and CRTC outputs.

 

As there is only one video signal input there is no good way to represent grayscale as a VGA video signal requires three channels (red, green, blue) to convey both luminosity and choma signals for color and shading/intensity. This is true even of non-color displays. So, the image from the camera would be rather badly scaled down for this monitor and would look almost like a solarized post processing effect without the proper ability to control gradations of luminosity in the video signal. 

 

Not impossible, but almost certainly a roll-your-own type proposition as I'm unaware of any off the shelf scan converter that would do this sort of signal conversion. There is also the small matter that the CRTC apparently employs a detect circuit for the presence of the monitor. If it (the monitor unit itself) is not "seen"  by the controller (CRTC) then the controller cuts the video output. I discovered this idiosyncratic behavior while messing around on trying to implement another custom enhancement that has not yet come to fruition.  And, after all that there is the issue that the image will be light blue-green monochrome. Not terrible, but certainly not as good as full color as one would find on contemporary backup camera  systems.

 

I think a better implementation would be a rear view mirrow with an integral small color LCD display hooked up to the camera for this purpose. I have seen such mirrors for sale online, some even pre-packaged as backup camera systems I believe.

Link to post
Share on other sites
37 minutes ago, KDirk said:

The CRT is a VGA computer monitor but operates at a resolution of 320x240, which is a fairly low resolution. I don't know if can display higher than that but as it was purpose built and lacks multi-sync logic circuitry on board, I suspect it's only capable of syncing to that resolution at a specific frequency (possibly 70Hz) and refresh rate. This may or may not be an interlaced video signal, I've not reverse engineered it far enough to say with certainty. To display a composite video signal such as that from a back up camera, you'd need a scan converter that could take a composite video signal, turn it into VGA (and monochrome at that, rather than RGB) at 320x240 at whatever frequency and refresh rate the monitor is expecting and then cut in a electronic video switch of some sort that would maintain sync between the camera and CRTC outputs.

 

As there is only one video signal input there is no good way to represent grayscale as a VGA video signal requires three channels (red, green, blue) to convey both luminosity and choma signals for color and shading/intensity. This is true even of non-color displays. So, the image from the camera would be rather badly scaled down for this monitor and would look almost like a solarized post processing effect without the proper ability to control gradations of luminosity in the video signal. 

 

Not impossible, but almost certainly a roll-your-own type proposition as I'm unaware of any off the shelf scan converter that would do this sort of signal conversion. There is also the small matter that the CRTC apparently employs a detect circuit for the presence of the monitor. If it (the monitor unit itself) is not "seen"  by the controller (CRTC) then the controller cuts the video output. I discovered this idiosyncratic behavior while messing around on trying to implement another custom enhancement that has not yet come to fruition.  And, after all that there is the issue that the image will be light blue-green monochrome. Not terrible, but certainly not as good as full color as one would find on contemporary backup camera  systems.

 

I think a better implementation would be a rear view mirrow with an integral small color LCD display hooked up to the camera for this purpose. I have seen such mirrors for sale online, some even pre-packaged as backup camera systems I believe.

ok. thanks anyway.i knew i could add a screen but it would be awesome for it to be built in to the car.

Link to post
Share on other sites

After reading Kevin's description of what would be required, I think it would be easier to make the driver's seat swivel 180 degrees so you could look out the back window when you want to see what's behind you. :D.

Link to post
Share on other sites

Wasn't  there a custom Toronado back in the early 70's that had swivel seats? Seems like I recall seeing a writeup about it somewhere. Might've been a George Barris job...

 

Actually, one could dispense with the outboard casette deck (on 88/89) since I see no residual value in it, and custom mount a 5" color LCD there that could display a back up cam, among other things. I've toyed around with mods to the CRT system, and some [limited] things are possible, but the system hardware really was spec'd only to do what you see (with the minor additions of the compass display and integral cell phone functions being options on the Riviera) with no real room for expansion.

 

Besides, the hardware used was an odd implementation and stripped pretty well to the bare bones for what GM wanted it to do (versus the putative capabilities that were planned for it in the patents filed by IBM). So, anything you'd  like to add would require heavy lifting in a hardware sense. One would best be knowledgeable about microcontroller and embedded system design as well as video interface standards and machine code programming on both the 8088 and 8051 series CPUs.

 

Back in the 80's guys that could hack this sort of stuff (if sufficiently motivated by their own curiosity and/or enough money/infamy) were fairly common. I did some fairly impressive and equally questionable stuff myself in the heydey of the PC and BBS's but now no almost one programs on the bare metal (heck, most would be lost at a Unix command prompt) and the low-level nuts and bolts knowledge to work on this kind of setup has been largely lost to time and supplanted by more "advanced" development tools that make cop-outs and short cuts possible for the so-called developers of this era. 

 

I have had a go at making some minor changes that suit my own needs. Some have been successful, some are awaiting a flash of brilliance to overcome inherent limitiations of the system as it exsits (like adding steering wheel controls). Mostly I lack the time and motivation to kill all night bit banging code and breadboarding interfacing circuits like I did as a teenager on a Pepsi and Hostess Cakes binge. Real life and responsibilities kinda killed that scene for me over 25 years ago, so I make a token effort at a few things and run out of steam when it's time to pay the bills. That, and doing stuff like this no longer holds my interest the way it used to. The magic and potential of computers was largely squandered in my opinion, and the tech that seemed so promising and limitless circa 1986 has turned into nothing more than a way for profiteers and other bad actors to exploit and enslave us all. Most have accepted this as just the way things are. Personally, it disgusts me. Check out the movie (or the book) Colussus: The Forbin Project sometime. Aw hell, now I went and got all philosphical.

Link to post
Share on other sites
5 hours ago, KDirk said:

Wasn't  there a custom Toronado back in the early 70's that had swivel seats? Seems like I recall seeing a writeup about it somewhere. Might've been a George Barris job...

 

Actually, one could dispense with the outboard casette deck (on 88/89) since I see no residual value in it, and custom mount a 5" color LCD there that could display a back up cam, among other things. I've toyed around with mods to the CRT system, and some [limited] things are possible, but the system hardware really was spec'd only to do what you see (with the minor additions of the compass display and integral cell phone functions being options on the Riviera) with no real room for expansion.

 

Besides, the hardware used was an odd implementation and stripped pretty well to the bare bones for what GM wanted it to do (versus the putative capabilities that were planned for it in the patents filed by IBM). So, anything you'd  like to add would require heavy lifting in a hardware sense. One would best be knowledgeable about microcontroller and embedded system design as well as video interface standards and machine code programming on both the 8088 and 8051 series CPUs.

 

Back in the 80's guys that could hack this sort of stuff (if sufficiently motivated by their own curiosity and/or enough money/infamy) were fairly common. I did some fairly impressive and equally questionable stuff myself in the heydey of the PC and BBS's but now no almost one programs on the bare metal (heck, most would be lost at a Unix command prompt) and the low-level nuts and bolts knowledge to work on this kind of setup has been largely lost to time and supplanted by more "advanced" development tools that make cop-outs and short cuts possible for the so-called developers of this era. 

 

I have had a go at making some minor changes that suit my own needs. Some have been successful, some are awaiting a flash of brilliance to overcome inherent limitiations of the system as it exsits (like adding steering wheel controls). Mostly I lack the time and motivation to kill all night bit banging code and breadboarding interfacing circuits like I did as a teenager on a Pepsi and Hostess Cakes binge. Real life and responsibilities kinda killed that scene for me over 25 years ago, so I make a token effort at a few things and run out of steam when it's time to pay the bills. That, and doing stuff like this no longer holds my interest the way it used to. The magic and potential of computers was largely squandered in my opinion, and the tech that seemed so promising and limitless circa 1986 has turned into nothing more than a way for profiteers and other bad actors to exploit and enslave us all. Most have accepted this as just the way things are. Personally, it disgusts me. Check out the movie (or the book) Colussus: The Forbin Project sometime. Aw hell, now I went and got all philosphical.

steering wheel controls is another thing my car needs.i have to take my eyes off the road for too long to adjust the radio volume.lol

Link to post
Share on other sites

Another possible solution, there are a number of rear view mirror camera kits that are available.  By replacing the existing rear mirror, you would lose the map lights, but would gain a rear camera view.  

Link to post
Share on other sites

I have a conceptual (on paper) plan for steering wheel controls in an 88/89. The issues are that it requires a steering column with a multi contact slip ring (can be pilfered from an 86-89 Riviera), a modified CRT and CRT controller,  a small microcontroller to interpret key presses from the steering wheel controls and send them to the CRT, and finally a modified steering wheel that has the needed buttons. This would be radio controls only, basic climate controls would be doable but require a bit more work.

 

Essentially, when using the steering wheel controls, it would switch from the current CRT screen (if other than radio or summary), then simulate the key presses (volume, seek, mute, preset) that would normally be made on the touchscreen, then return the screen display to what was previously shown prior to using the radio controls. A similar approach could be used for the climate controls. If this sounds complicated, that's because it is.

 

Unfortunately, even if one could devise a way to transmit the correct E&C bus commands directly to the CRTC, radio module and the AC programmer, the CRT would lose sync on what is displayed (like radio station readout or commanded temperature and fan speed) since the CRTC does not follow commands sent from an external device and update what is on the screen accordingly. So, the only way to do it reliably is to interject "keypresses" that simulate pressing a particular button on the touch screen between the CRT and CRTC, and for that to work the screen needs to be showing the page that contains the specific mode you wish to control. Really, this whole thing is a kludge due to the way GM had it implemented. It would work, but it's complexity makes it rather unattractive to implement. Which is  not to say I won't  do it (I am a stubborn ol' cuss after all) but it will not be something that I could offer as a plug and play upgrade, especially since some of the parts (like the column) are difficult to come by.

Link to post
Share on other sites
  • 1 month later...

As usual, what Kdirk said.     

 

What I highly suggest is using a 7" display where the tape deck is:  DSC_0381.JPG

 

I have a PC driving this with Centrafuse as the UI.  I also have a reverse-camera (License plate frame style) that the LCD controller automatically switches to for an input when I put the car in reverse. This is by far the most ideal and lease resistive option. I am all for reverse engineering, but the results would still have fell short so a secondary display was best regardless.. In the least so that you can always have the cars integrated functions + your additions up at once.  

 

The freedom of a PC makes it trivial to add a multitude of additions, and often wireless, such as steering buttons, that can be custom labeled and bound to any function.  My factory head-unit is never used at this point unless I want to use FM/AM, which I never do anymore... and so you have full control of the volume via software measures.   You can use Windows, build your own UI on any platform, use Linux, or a Raspberry Pi, whatever you like..   A standard LCD was freeing.. messing with proprietary is fun for the challenge, but seeing as it would likely reduce reliability by adding cruft/complexity, I'd rather leave it as we cannot deny it's rock-solid as is.. Not something I can say for modern embedded systems.. even our dishwasher has to be rebooted sometimes. :)   They knew how to write software back then.

 

Link to post
Share on other sites

Ok, off topic, but it is in my DVD library as well. Dated in its presentation naturally, but still impressive and quite well done in my opinion. They only made the first of the three novels in the series into a movie. If you really want to get bogged down in some depressingly heavy stuff, read the second and third novels.

 

Spoiler: no happy ending for this one, probably why Hollywood abandoned it after the first outing. At least it had an ambiguous and somewhat defiant ending, which was fashinoable in 1970's American filmmaking.  This movie wouldn't be made now, at least not without being wildly divergent from the original  source material.

 

Back on topic: the system Fox presented is the better solution by far. Yes, it is not purist in it's integration or appearance (though the screen output could be skinned to look like the CRT 8 bit monochrome graphics if one really wanted to maintain the overall aesthetic).

 

This is probably the direction I am going since prolonged considerstion of modding the stock CRT system has left me less than enthusiastic about doing the work needed to get what I want out of it. Too much effort just to be able to say I did it, and it still would be lacking features I really desire. As I like to say, just because something can be done, doesn't make it worth doing.

 

Link to post
Share on other sites

Ok, off topic, but it is in my DVD library as well. Dated in its presentation naturally, but still impressive and quite well done in my opinion. They only made the first of the three novels in the series into a movie. If you really want to get bogged down in some depressingly heavy stuff, read the second and third novels.

 

Spoiler: no happy ending for this one, probably why Hollywood abandoned it after the first outing. At least it had an ambiguous and somewhat defiant ending, which was fashinoable in 1970's American filmmaking.  This movie wouldn't be made now, at least not without being wildly divergent from the original  source material.

 

Back on topic: the system Fox presented is the better solution by far. Yes, it is not purist in it's integration or appearance (though the screen output could be skinned to look like the CRT 8 bit monochrome graphics if one really wanted to maintain the overall aesthetic).

 

This is probably the direction I am going since prolonged considerstion of modding the stock CRT system has left me less than enthusiastic about doing the work needed to get what I want out of it. Too much effort just to be able to say I did it, and it still would be lacking features I really desire. As I like to say, just because something can be done, doesn't make it worth doing.

 

Link to post
Share on other sites

I have over 500 albums on my cell phone & sounds much better than satellite.

 

For me the hard part was finding a wireless BUC that could reach from the back of the trailer to the tow vehicle. Had to use WiFi.  Reattas do not need a camera.

 

Link to post
Share on other sites
10 hours ago, padgett said:

 Reattas do not need a camera.

 

I agree with that. I have an Equinox with a backup camera and I never remember to use it. I think a audible backup warning system would be a better option.

Link to post
Share on other sites

If you are unhappy with your Reatta the way it was built and want some of the "conveniences" put on automobiles in the last 25 year, there is a solution.

Buy a new Buick and put Reatta badges on it, now you have a Reatta with everything you are seeking.

PS.......have you seen the pictures of the new 2017 Lacrosse, I think it looks really nice......as nice as anything offered by GM

Link to post
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...