Adding PSX controller port to Atari Lynx, need info

I want to add a PSX controller port to my old Atari Lynx so I can use more comfortable controller while playing Lynx. I'm thinking of using arduino to decode PSX controller data and feed them to Lynx button inputs. But arduino normally runs at 5v and PSX controller (official Sony) is designed to run at 3.3v Would that be an issue or can I get away with 5v. Or is there something a little easier that can do serial data in, parallel out for PSX controller to Lynx board?

I'm doing this mod along with another mod when it arrives in the mail: the long awaited Lynx to TV adapter. This forum thread talks about that: http://atariage.com/forums/topic/202796-lynx-to-vga/ (also can do replacement internal LCD as well)

picture and video from the guy who developed Lynx board for replacing stock LCD with newer one and eventually got video out as well.




As you can see there's big improvement. The original LCD, being based on very early color LCD technology suffers from slow refresh rate causing blur, weak and washed out color, limited viewing angle, and required power guzzling CCFL for backlighting as white LED wouldn't be invented for another 15 years. Newer LCD has clearer and more vivid color, wider viewing angle, efficient LEDs, making it a very desirable upgrade option.

Note, at this time only Lynx 2 is supported. Lynx 1 is quite different internally and the person said it's weird.

 

Uhh... what?! The first white LED was made in 1997, only 8 years after Atari released the Lynx.

If the voltage is going to be an issue (not sure what's in the PSX controller so couldn't say), use a level shifter.

 

True the first white LED was in '97 but early white LED were expensive as heck. I remember seeing blue LEDs going for $1 each at the cheapest and it wasn't bright either. Cheap white LED wouldn't be out for a few more years.

I'll look into level shifter, thanks for the tip.

 

The joystick wiring in the Lynx is really simple - all the switches are just wired to +5V with no multiplexing at all. Another interesting thing is that all the signals you need except for the pause button are on the cartridge port - the same lines are used for ROM data and joystick inputs, and there is a +5V on the cart. port, too - if you are going to do this, then you should wire 4K7 resistors in series with the switches to protect the drivers in the ROM cart if you have the joystick buttons pressed when the Lynx is booting up. From memory, the joystick lines are pins 2 through 9 on the card connector and +5V is one pin from the end (pin 33, I think).

 

Yeah Lynx is simple to wire but the problem is PSX is 3.3v and logic high at 3.3v may not work properly with the arduino. I'd need to use level shifter or just run 5v into PSX and hope it won't burn the controller out.

 

I've run the original (digital only) PSX controllers at 5V - they seemed to work with no problems, although it's certainly true that a real PSX outputs about 3.4V on the power pin...