Just purchased a second hand GRID from a chap on Ebay. It's not a Compass II like the ones from Aliens, but a 1550SX model. But it looks the part..

Picked this up relatively cheaply as its not- working, which I intend to gut and stick a Raspberry Pi in its place, like Hawkins did with his.

I'm planning on documenting everything for a possible YouTube video, so progress will be slow as I'll be filming everything, but will keep you posted here with pics.

Incidentally, against my better judgement, I decided to plug in the powerpack and see what happened. Needless to say this was not a good idea, as it started to boot then smoke duly started to appear from the back

Still cant get the electrical burning smell out of the shed.

Anyway, here's some pics. Next stage is gutting it...

Good find! It does look the part.
Hope you find an easy to make "it" work again.
Looking forward seeing your progress. Good luck!

_________________
Sgt. Frank Peters 'reload' Smartgun Operator
A03/TQ3.0.12136E1 "It will be no picknick!"
AL Colonial Admin. - Sergeant at Arms (SgtA) -- 2020-2022
GERCM - Executive Officer (XO)
UKCM Foreign Legion: The Deviant Dragoons

One option for functionality would be if you could find a tablet the right size. Installing a modern laptop in there would be more challenging.

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Sci-Firepower Prop Collection:
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A raspberry pi would work instead. You can wire up the built-in keyboard and replace the display in it as well.

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The impossible takes a while longer and goes over budget too...

That's the plan!

Gutted...

Not much done today as I'm still waiting on parts to arrive. But I cleaned up the outer case and applied some car trim black, to restore the colour.

Neato! Good luck with the build!

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"I'm working on it ... "

Little bit more done.

I was fortunate to find a supplier that sells old style 4:3 ratio screens for mini arcade builds, which was only slightly smaller than the screen I took out.

I mounted the new screen inside the frame of the old one. With the new screen being slightly smaller, I cut some strips of plastic to use as spacers so the screen sits centrally in it. Then mounted them on a backing piece by carefully dabbing a bit of solvent cement on them.

I then mounted the whole thing inside the old screen panel by cutting out another piece of ABS the same size as the old circuit board, which attached to the frame. Then screwed that to the panel.

Here are the pics, so you get the idea.

Progress is slow as I've been waiting on some bits to arrive, plus dealing with a few personal issues which has sapped a lot of the fun out of the project, but I'm attempting to persevere...

Watching this - I will likely try the same thing at some point.

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Sci-Firepower Prop Collection:
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Another option would have been to forgo the old frame, get a screen thats about the right width, if you can't find an old style 4:3 ratio screen, and simply mount it on a piece of plastic stuck behind the panel

I've got a Raspberry Pi all ready to go, next step is mounting the circuit board on the back of the panel, but just waiting on some bits from Ebay.

Progress is coming along slowly.

Wanted to stick a bit of thick plastic on the back and screw the circuit boards onto those, BUT I couldn't find any screws small enough to mount these on.

The holes in the tiny circuit boards are like 1mm or something and the smallest screws I can get are 2mm.

So, I just bodged it using some hot glue.

Then I tested the finished screen with the Raspberry Pi to ensure it works, and it did. Next step, sorting the keyboard out.

Well that was a bloody boring afternoon, spent most of the day mapping which connections connected to which keys.

VERY dull and very time consuming.

Also spent some time trying to figure out how this rather crude pointing device/mouse worked. Got some very strange readings from my test meter, might have to leave that disconnected for now.

Keyboard wired up and soldered to the Teensy board.

The Teensy has 26 numbered pin holes 0-25. I had a total of 24 cables coming out of the Keyboard, so connected them to pin holes 1-24.

Just busy typing up the code to program this thing, then HOPEFULLY it should work...

You're doing a wonderful job of what is quite an undertaking. I bet it'll look fab.

OK, think I've about cracked this job now

The original tutorial on Instructables I was following, which Hawkins used for his GRiD retrofit, didn't work on mine. The code produced multiple characters when typing. So had to start over using a different method.

This meant having to re-do some of the connections on the Teensy, as you need to leave pin 13 free, as that one works the LED on the board and can cause all sorts of problems hooking another connection up to it.

Basically, rather than using a tester to work out with keys connect to which cables, you wire up all the cables to the Teensy first, then run this program and it will tell you which wires work which keys. Although the numbers it gives dont directly correlate to the pins on the Teensy, theres a little conversion chart you have to look at to work that out.

Anyway, you then have to work out which numbers are inputs and outputs, draw a table up and fill out the code accordingly.

Basically my keyboard had 11 outputs and 13 inputs, which are represented as rows and columns. You just fill out the relevant keycode in the corresponding row and column of your table and leave a zero if theres no key in a particular row or column as a placeholder.

You've probably no idea what I'm on about, and I'm not sure I understand this coding makarky myself, but it works.

This was the tutorial I used, the guy who published it, Frank Adams, also produces custom laptop keyboard connectors to enable you to connect any laptop to one of these Teensy Boards, but I was able to just use Ribbon cables with jumper pins on.

https://www.instructables.com/id/How-to ... ontroller/

Incidentally, I really can't thank Frank enough on this. When I was having some difficulty with the coding, he emailed me and showed me where I'd gone wrong and helped me sort it out. Wonderful guy!

great work, that's going to look epic.

Progress has been slow as I've been trying to figure out how the mouse/slide bar worked.

Anyway, Frank Adams, who provided me with the code for the keyboard, sent me an updated version, which allows me to connect LEDs to pin 13 for the Caps Lock and Pin 0 for the Number Lock.

He recommended using 2ma LEDs with a 715ohm resistor, so I knocked a couple of them up and soldered a couple of dupont pin cable to them. Then glued them to the lenses in the case, corresponding to where the original LEDs would have been.

Rather than soldering them direct to the teensy, I used a couple of Male to Female cables so I could just uncouple them if I wanted to remove the case.

So for anyone following the build the 11 Ouput pins on the Keyboard connect to pins 1-11, the 13 Input pins connect to pin 12, then pins 14-25 (missing out pin 13).

The couplings for the Caps Lock connect to pins 13 & ground and the couplings for the Num Lock go to 0 and Ground.

Anyway, here's a few pics showing the Teensy and how everything is connected....

THE MOUSE WORKS!!!!!!

Terrific news, managed to get the built-in mouse to work.

I was very VERY fortunate, the chap who sent me the code for the Keyboard happens to be a retired Boeing engineer and knows a thing or two about electronics and is big on recycling old laptop parts, so knows how to re-purpose old touch pads, mice and various retro pointing devices, so helped guide me through a series of tests in order to work out what each wire did.

It did mean procurring an oscilloscope for some of the tests, but fortunately one of my engineer friends had one, so after various trips to my friends house and videoing the results, we determined that (counting the wires from the RIGHT)...

Wire 1 - Ground
Wire 2 - 3v supply
Wire 3 & 4 - left and right signals
Wire 5 & 6 - up and down signals
Wire 7 - Right click
Wire 8 - Left click

It's worth noting that there appear to be 4 buttons on the mouse. The inner buttons are moulded to the central bar, so pushing these or the centre section down works the left click. The outer buttons are seperate, but connected electronically, and work the right click.

The bar in the middle scrolls forward and back to make the cursor go up and down and slides left and right to move the cursor left and right. There's also a couple of switches either side of the slide bar, so if you don't have enough lattitude to move the cursor all the way to the side, the slide bar will press against the switch, which will keep the cursor moving (hope I've explained that OK?).

Apparently the mouse uses rotary encoders (like they use on electronic speedometers on cars), so after analysing the oscilloscope signals. he was able to provide me with a code that got it to work.

I had to use a seperate Teensy as there weren't enough spare connections on the one I used for the keyboard.

The code also allows you to alter the speed of the cursor, by shorting out either Pin 0 or Pin 1 to ground on the Teensy, so I attached a short male lead to the ground and a couple of short female jumper cables to 0 & 1 on the Teensy. Which after some playing about, decided to leave it shorted to 0, as that allowed me to move the cursor almost the entire width of the screen with one movement.

Whereas the cursor tried to go off screen when shorted to Pin 1 and didnt move far enough when left unshorted to either.

Again, I really, really MUST thank Frank Adams for the code and helping me with this as I doubt I would have been able to do this without him.

Here are his pages on the instructables website... https://www.instructables.com/member/Frank_Adams/

Anyway, here's some more pics.

All that remains now s to put everything back togethor again, which is not as easy as it sounds...

But will it run Crysis? :p

Nah, this is all very cool stuff, mate. I tried programming boards and things once, with the guidance of a member here, but electrickery is utter magic to me and incomprehensible esoteric things that I simply cannot fathom. I look forward to seeing the final results!

I don't really know the first thing about coding either, but I am able to follow tutorials and stuff, so was able to muddle through. Which is one of the reasons it took so long, as I would have to wait till my day off to do some tinkering. Email my findings, wait for the response, then wait till my next day off to do the next set of tests and so on.

Again, I was very VERY fortunate to meet someone online who knows so much and likes doing this sort of thing as a hobby and was so willing to help, not to mention patient with me. So, cannot praise Frank highly enough here.

Think I have virtually everything I need to finish the project now. The only problem is time, as there's really only one day a week I can work on this, and because I'm videoing everything a good portion of time is spent setting things up for the video, rather than getting on wih the work. So its slow going.

I'll get there in the end. Editing the video is going to be a bitch though, what with all the hours of footage I've accumulated.

Very cool!

Am looking forward to seeing your videos at some point (as I've a GRiD as well that I want to convert).

Would you be able to put up a parts list too please?
I've got a Teensy LC board, but I'm really struggling to find an appropriate screen ...

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Cpl Aron "septic" Williams
A10/TQ0.0.82146E1

Try looking at mini-arcade monitors.

I will attempt to do a parts list at the end, one thing I WILL tell you to do now. DON'T do what I did and solder the dupont pin cable directly onto the Teensy. Get some header pins, solder those onto the board and connect to them using Female dupont cables. Much easier to swap the cables round if you screw something up that way.

GETTING THERE.

Mouse re-attached to the keyboard.

I've glued velcro to the underside of the keyboard and to the plugs from the keyboard and mouse to secure them to the underside. Done this for 2 reasons, in the case of the mouse I wanted to reduce the stress on the flimsy wires that go from the plug to the mouse circuit board (already had to re-solder one wire, which was a major pain). In the case of the keyboard, as there is limited space in the back of the laptop, thought it best to tuck the cables from the Teensy under the keyboard, and loop them round, so the velcro keeps the plugs in place.

Then it was just a case of screwing the keyboard and mouse back into the case and clipping the top plate back into place.

You can see the male and female sockets that connect the Teensy to the Caps and Num lock LEDs in a couple of pics.

Putting the screen back is next.

Just hope it all works once bolted back togethor.

Not a lot of progress this weekend unfortunately.

Obviously, as I gutted the laptop, I can't use the built in power supply (yet), so for now I'm going to be using a standard 12v Laptop powerpack.

So, have added a 5mm DC power socket to the space where the original socket would have been (which had a rather unique connection). Which I've soldered some cables to.

The on/off switch was sat on a circuit board behind a hole in a case. Fortunately the switch was the same size as the hole, so I desoldered it and fitted it externally (will solder the incoming supply to it once the rear panel is fitted in the case, so I know where to route the cables).

Removed the old peripheral sockets, fitted a couple of USB sockets and an HDMI out to the rear panel, which will plug into the Raspberry Pi and blanked off the unused outlets with a bit of black ABS plastic and some epoxy.

Though not visible, I also glued an Ethernet coupling to the rear of the case, which will plug into the Pi's Ethernet socket and again blanked off the unused outlets with soe ABS and epoxy.

And that's about as far as I've got, not sure how I'm going to fit all these cables into the case, but I guess we'll cross that bridge when we get to it!