Worklog DS Lite in a TI-Nspire Calculator Case

[EggoMyLego2]

Hey, I'm working on my first proper console mod!
I'm going to put a DS Lite into a calculator case, one of the older Nspire models.

I have decided to go with the original TI-Nspire CAS. It seems to be the best option for my needs. This is for a few reasons:

1. The case should be large enough and thick enough for a DS Lite motherboard along with everything else needed (screen, charger, speaker, buttons)
2. The cutout for the screen is larger than other calculators such as the T-83 or the TI-89. On my more modern TI-Nspire CX CAS calculator, I measure the screen to be around 3.3in, while the DS lite screen is closer to 3.3 in as well (including the bezel). As far as I know, the original model Nspire has the same sized screen as the newer ones (it's hard to find specific info online).
3. This model of calculator has a directional pad closer to the middle, instead of on the right side (like on the TI-83 or TI-89. Having the directional pad in the middle is more comfortable than on the right side.
4. In addition, this calculator is not like the newer calculators with the touch pad. It would probably be difficult for me to use the touchpad since it is is very non-standard compared to the traditional button pad. Interfacing with the ribbon cable would be a headache.
5. The non-cas original TI-Nspire has some sort of removable button pad which could be difficult to work with. The CAS version does not have this feature as far as I know.

I've seen others put a GBA in calculators before, such as zeldaxpro, who has done an amazing job on his: here

Similarly, I've seen others such as haihaisb put a DS lite in a DMG case. Both of these have been a huge inspiration for this project. Though I haven't seen anyone put a DS inside of a calculator

I'd prefer to use a DS lite instead since it has a lot more features, and there is a very large game library with emulation and backwards compatibility (NES/SNES/GB(C)/GBA/NDS). Not all games will be playable though due to only having one screen. Also, the price of anything involving the GBA has been quite inflated recently. DS Lite consoles and parts are a lot cheaper and easier to get ahold of.

A few things to note:

• The DS lite refuses to boot without the top screen, but you can get around this by soldering a resistor to certain pads on the motherboard (lookup gameboy macro)
• I plan to get rid of the top screen and keep the touchscreen. I know certain homebrew apps are impossible to use without touch functionality (such as nesDS). I don't plan to hack up a ribbon cable, but rather use one of these adapters from aliexpress here. I've heard that this adapter works perfectly for what I need.
• I can't say that I'm experienced enough to relocate the game slots. I plan on removing the GBA slot and using GBARunner2 with TWiLightMenu++ to play GBA games. I'm aiming to keep the DS slot where it is, and having the slot be on the side of the calculator.
• Even though I'm not very experienced, I still know my way around a DS Lite, and I do have some soldering skills.

Anyway... For now, I have ordered a broken TI-Nspire CAS, the screen adapter, resistors, and some kapton tape. I already have some materials like the DS lite+extra parts, soldering iron, high quality solder, heat gun, r4 flashcard, etc.
As for what I still need. I'm looking into smaller magnet wire, as well as some silicone wire. Would love to see some suggestions for which to get, as I've never done anything like this before.

Thanks for reading. I'd love to see what others have to say about this!

 

[Dmcke5]

Love it! Keen to see some pics as you progress. Such a weird project, its great haha

 

[EggoMyLego2]

Hi again, time for an update!

I got my calculator in the mail, some more ds parts, kapton tape, and 330ohm resistors.

The majority of this post is going to be photo spam...
Before this though... time for some SMB3!

As you can tell, the calculator has some screen issues, but it still works enough for me to install an NES emulator. More info at http://ndless.me/

Enough goofing around... Time to actually tear this thing apart

It was quite annoying to disassemble, since there was some adhesive and a lot of plastic clamps. Some of the PCBs have some weird melted plastic which I had to break off in order to get the PCB out.

I can tell that I'm going to need to do a lot of cutting in the case, especially around the battery holders.

The directional pad uses a strange 8 contact layout for the diagonals. I don't think this will be too much of an issue to map to the DS. If I do a bit of trimming on the rubber, I think the dpad would sink far enough to register 2 inputs. I would most likely be able to get rid of the 4 extra pads.

Looks like the calculator screen was a bit larger than I was expecting. No worries, since it's much easier to tape out the sides, rather than make a larger opening for the DS screen.

After some test fitting with the motherboard... It looks like this mod won't be too difficult.
I have to do a bit of case trimming so the motherboard can sink down a bit, but I might be able to keep the GBA slot. If not, I could go for an internal EZFlash Omega. This GBA flashcart can be fit in a smaller shell to fit in the DS lite cleanly. Not too sure about this though, since all the gba games I want to play run fine with GBARunner2 (which does not use slot 2).

I tried to fit a ds phat motherboard inside the case, and it looks like it just barely fits. I know the original ds can be modded to switch between the top/bottom screen, while the ds lite cannot. The original DS also has a very long top screen ribbon cable, which would not need an adapter.
Maybe I could use an OG ds for version 2 of this mod?

Anyway, here's what I still need to do:

• Rewire buttons
• Wire touchscreen (soldering to a ribbon cable, yay!)
• Add 330ohm resistor so the DS can boot without a top screen
• Rewire volume/power switches
• Possibly rewire charging port? The calculator has a spot for a mini usb cable at the top, and it would be lame to not have the charging port up there.
• Install screen adapter (could take awhile, it's coming from china)

I could be missing something here, but I think I got it for the most part.

That's all for now... Until next time!