DS r4 built-in

[Nothing_6666]

Hi everyone, I’ve been thinking about a project for my DS Lite and wanted to get some feedback.


The idea:


I’d like to create a DS Lite that can:

1. Use real DS cartridges as normal
2. Use an SD card as a “DS cart” without relying on a flashcart shell
3. Switch between the two using a physical toggle

How I’m thinking about doing it:

• Use a DS Lite Slot-1 PCB or a donor DS cart PCB as the connector
• Jumper-wire the R4 PCB traces directly to the DS Lite Slot-1 pins (data, address, control, and power lines)
• Add a SPDT or toggle switch to select between the R4 (SD card) and real cartridges
• Ensure proper power isolation so both the R4 and real carts don’t conflict

Potential challenges:

• The DS Lite bus timing is precise, so any loose connections or interference could cause instability
• Switching lines while the DS Lite is powered could damage the hardware
• Mapping all the pins correctly will require careful planning
• Might need tri-state buffers or bus switches for safe isolation

Questions for the community:

1. Has anyone tried wiring a flashcart directly to a DS Lite PCB like this?
2. Would a simple toggle switch be sufficient if the DS Lite is powered off during switching?
3. Are there recommended techniques for mapping the R4 pins to the DS Lite Slot-1 safely?
4. Any tips on adding buffers or isolating signals to prevent issues?

I realize this is more complex than using a standard flashcart, but I’m interested in exploring the hardware side. Any insights or suggestions would be appreciated.


— Nothing

 

[VinsCool]

I don't see why this couldn't work, assuming it could be as easy as soldering a few wires and a switch somewhere in the process.

In practice, however, this seems pretty cumbersome for effectively the same results done from simply swapping carts, so what is the gain from such a project other than modding achievements?

Surely, someone would have done already it if there was a practical reason for it.
Owning a hacked Nintendo DSi would be essentially the same thing at this point.

 

[Nothing_6666]

I don't see why this couldn't work, assuming it could be as easy as soldering a few wires and a switch somewhere in the process.

In practice, however, this seems pretty cumbersome for effectively the same results done from simply swapping carts, so what is the gain from such a project other than modding achievements?

Surely, someone would have done already it if there was a practical reason for it.
Owning a hacked Nintendo DSi would be essentially the same thing at this point.

The only real point it would server would to ensure you dont lose your r4 ig

 

[TheStonedModder]

I don't see why this couldn't work, assuming it could be as easy as soldering a few wires and a switch somewhere in the process.

In practice, however, this seems pretty cumbersome for effectively the same results done from simply swapping carts, so what is the gain from such a project other than modding achievements?

Surely, someone would have done already it if there was a practical reason for it.
Owning a hacked Nintendo DSi would be essentially the same thing at this point.

Low key would probably be much easier to just make a cart extension with two slots and a switch instead of going internal

Kinda of like what action replay did

 

[Nothing_6666]

Low key would probably be much easier to just make a cart extension with two slots and a switch instead of going internal

Kinda of like what action replay did

yeah i have been thinking about this mod over that past couple of days and realized it would be easier to just make a ds cartridge "usb hub" if that makes any sense