PSP Keyboard through serial

adrahil · Post by **adrahil** » Sat Jul 15, 2006 6:01 pm

Hi everybody!

I have been investigating lately into the possibility of plugging in a keyboard into the PSP, partly because it's a pain to type in afkim with the OSK... Well, I've found some interesting stuff, including a PS/2 interface for a PIC16F84. This pic then sends the characters in ascii to an rs232 converter and then to the PC. Well, I though that I could adapt this for the PSP, by removing the rs232 converter and directly attaching one of the PSP's remote wires to the data output of the PIC. Then, another addition would be to change the PIC16f84 to a PIC16LF84A because a) you can get those free from Microchip.com, and b) Their power requirement is not 5[V] but between 2 and 3[V]. The keyboard would be plugged to a 5[V] battery and the PIC would feed from the PSP. Well, basically that's it... I'll go get the parts next weekend, start soldering, debugging, and tell you how it's going.

If anyone is interested, here are the references:
http://www.electronic-engineering.ch/mi ... _v1xx.html [Schematics and picASM]
http://sample.microchip.com/ [Samples of PICs and whatever else]

danzel · Post by **danzel** » Sun Jul 16, 2006 8:01 pm

I am very interested in this project :D

Please keep me informed, I would like to wire one up for myself and get support for it into my apps :)))))))))))))))))))))))))))))))

futaris · Post by **futaris** » Wed Jul 19, 2006 2:06 pm

Cripes. This is compicated, and you'd have to physically move/attach it somehow. The easiest method is to use an IR keyboard designed for a Pocket PC, etc or a Stowaway Keyboard. The Stowaway for the Visor should work off 2.5V levels and interface at the right levels The other option is a Ericsson Chatboard... See GBA or GP2X forums for more info about the chatboard.

adrahil · Post by **adrahil** » Thu Jul 20, 2006 11:49 pm

This is compicated

Well, not really... If you have a look at the schema, you'll see that this is a trivial circuit to build...

you'd have to physically move/attach it somehow

Well, there isn't any problem with that, since with any keyboard you'd have to do it... The PS/2 just gives you a bit more freedom. Just look at the stowaway keyboard, it has to be physically close to the device... This is why infrared is not my choice. A PS/2 keyboard can have a long cable, and the adapter sticked to the back of the PSP, or even part of a holding device...

The easiest method is to use an IR keyboard designed for a Pocket PC, etc or a Stowaway Keyboard.

There are two reasons not to use this: price and compatibility. First, price: The whole PS/2->PSP including keyboard will cost at most 10$... This includes everything, since the PIC is free from Microchip :P
Then, the problem with these keyboards is that they give a driver specifically built for that system, as I really doubt they send unicode or control characters directly... Therefore each different keyboard would need a driver developed for it... If you want to do it, go ahead :) This PIC-based PS/2 circuit has the advantage of compatibility with all standart PS/2 keyboards, plus it is faster to program in PIC assembler to implement low-level character handling. (The ASM program which comes with it is quite sufficient and sends the output in ASCII characters to the output pin ;))

The Stowaway for the Visor should work off 2.5V levels and interface at the right levels The other option is a Ericsson Chatboard...

Well, this would eat up a lot of battery this way... I'm planning on adding a 5[V] battery (3-4 AAA batteries I guess, or a simple accumulator) and feed the PIC from the SIO, which will be a bit better for the PSP's lifetime.

Of course, all the solutions you're presenting are viable alternatives to PS/2, but I just prefer to do it my way, since it is quite easy to do ;)

futaris · Post by **futaris** » Fri Jul 21, 2006 2:22 pm

Each to their own. You do realise that the PIC is going to draw more current than a Stowaway Keyboard, or similar. Most of these use only in the order of 100uA - 10mA. But if you're using an external battery it doesn't really matter.

The problem is you're still going to have to come up with a serial protocol for keyup/keydown, etc... And these protocols have already been written, etc. Handhelds.org have already done a half a dozen keymaps for different keyboards, and the code is trivial. I know people have already done this stuff before for the Ipaq and similar, so you can probably save yourself reinventing the entire wheel/code.

- http://web.archive.org/web/*/http://www ... s2ser.html
- http://handhelds.org/moin/moin.cgi/kbdd

And you will need 5V for the PS/2 cable, since PS/2 runs at 5V levels - which is why you need your batteries. That being said, if you want to create some code, at least make it so we can plug in a PS/2 Mouse as well, if we want. For this you might as well just write a Synergy prx that will let you drag your keyboard/mouse over to the PS2 and back to your PC again. It could just be a modification of the current OSK...

http://synergy2.sourceforge.net/Synergy

Anyhow, just as long as we create a "standard" on the PSP for Keyboard input then it will make interfacing various apps/games to it easier later on.

Ostehovel · Post by **Ostehovel** » Fri Sep 22, 2006 1:19 am

I have now plaste my order on the PIC and the MAXIS3232 chip..
and when i get them i will start to debug and test...

harleyg · Post by **harleyg** » Fri Sep 22, 2006 4:46 am

I have already played around with ps2 to sio, shouldn't be too hard adrahil. :)

adrahil · Post by **adrahil** » Fri Sep 22, 2006 7:29 am

No, it isn't that hard, but it's a pain to order parts from switzerland :(
The chips still didn't arrive...

neotomek · Post by **neotomek** » Sat Sep 23, 2006 4:57 am

My psp keyboard project : PS/2 keyboard convert o psp uart
It's woking :)

Photo : http://rapidshare.de/files/34061922/psp.jpg

Atmega8 , dev board , resistors , ps/2 conector .

Site about project:
www.neotomek.blogspot.com

harleyg · Post by **harleyg** » Sat Sep 23, 2006 6:40 am

Nice work.
What did you use for the software side? I'm guessing the samples?

Ostehovel · Post by **Ostehovel** » Mon Oct 09, 2006 1:46 am

I have made a HomePage for my PSPkeyboard project here: http://pspkeyboard.ostsoft.ath.cx

digihoe · Post by **digihoe** » Mon Oct 16, 2006 8:02 am

This kind of reminds me of what I tried to get started a while ago...

http://forums.ps2dev.org/viewtopic.php? ... highlight=

Best regards!

Grizzly_cf · Post by **Grizzly_cf** » Tue Oct 31, 2006 8:33 am

Hi

Short time ago I'm return to my project Ericsson chatboard CHA-01<>PSP.

I got new experience about UART in PSP.
I done PSP<>PC converter:

And writen a program PSP UART Terminal (now ver0.3) DOWNLOAD to testing/working with UART port.

Features:
- Works in 4 baud rate's (2400, 4800, 9600 and 19200)
- 2 mode's of reciving data: Single char, stream text (512char max, end of transmission when Carriege Return)
- Display on LCD
- Optional save reviced data to file
- ECHO mode
- Send one of 3 cons. strings ("tekst1\n", "tekst2\n", "OK",13,10,0)
- Return to configuration from reciving mode

TO-DO:
- customizing string in ext. file to send on the port
- displaing info on the screen when data send
- support with CHA-01
- exit option in configuration mode

TO-FIX:
- problem with buttons in streaming text mode

Link to polish thread Here

When I run CHA-01 in PSP UART Terminal I will do new program special to using CHA-01. I search for some advantages about simulate push buttons (for now I find only This) and background work programs (like pspcapture, pspshot, MP3 IRshell plug-in etc.)