Hi, i inform a successful making SIO cable for PSP slim.
My circuit is this - http://lab.halzion.net/img/hardware/psp ... _cable.gif
and I refer to few web site
http://deniska.dcemu.co.uk/simple-slim- ... 77267.html
http://mc.pp.se/psp/phones.xhtml
and datasheet
http://datasheets.maxim-ic.com/en/ds/MAX3218.pdf
but it is very noisy
i can send data PC -> PSP (use sioDriver.prx), by 9600 ... 57600
but sending data PSP -> PC is not at all.
and like this 50%, can send data by 115200bps
I think cause is only -4V at V- pin, and I try to change C4 2μF, 3μF ...
voltage of V- is drop down.
if you made this circuit, I thin more better to change C4 4.7μF
and i use OS-CON in C4, my psp is break down!! ;)
sorry my poor English.
I success to make sio cable for PSP slim
I haven't tried it myself, but something like the DLP-TxRx-G would make a nice SIO interface if you're only interested in communicating with a PC or other USB-capable host. It's based on FT232RL which handles VCCIO down to 1.8V.