PSP serial adapter

Jim Paris <>

This level-shifting serial adapter for the PSP (and other devices) is based on the MAX3319E interface chip. This chip provides guaranteed 460kbps RS-232 compatible operation with a supply as low as +2.25V, making it a perfect choice for the +2.5V supply and logic interface on the PSP.

The board supports either a male or female DB9 connector in a DTE or DCE configuration, selectable with solder jumpers during assembly. Typically, to avoid the need for adapters and “null-modem” cables, female/DCE is used to connect the PSP to a PC, while male/DTE is used to connect the PSP to other devices like a GPS.

It was designed to fit comfortably inside a DB9 plastic hood. Four holes with 2.54mm spacing provide the power and data connections to the PSP.

LabelDescriptionPSP Pin
VSupply voltage, +2.25V to +3.0V5, +2.5V
GGround2, Digital ground
INSerial input to the adapter3, TXD
OUTSerial output from the adapter6, RXD

A small number of these adapters are for sale. Please note that I haven't found a good source for the PSP cable, and so these are being sold with everything except the cable, as shown below.

The complete kit contains

You need to obtain and solder your own cable to the adapter. My white cable came from a standard PSP headphone remote, and I took the short black one from a set of third-party headphones. Others have made their own cables and connectors for the PSP.

The cost is US $8 per adapter, and shipping is US $4 per order (USPS Priority Mail or USPS Global Priority Mail). Send money and a shipping address via PayPal to