Editing Serial Adapter

The PSP's headphone remote (HPRM) port contains a connection to UART4 in order to implement rewind, fast forward, and play / pause. This connector is often repurposed for debugging.

Below are the HPRM pinouts for various PSP models along with instructions on how to build your own HPRM to serial adapter.

== PSP-1000 ==
This was originally documented by [http://mc.pp.se/psp/phones.xhtml Marcus Comstedt] More information on the HPRM serial protocol can be found on his page.

The PSP-1000's HPRM port operates at 2.5v
[[File:Psp-1000 hprm port.jpg|alt=PSP-1000 headphone remote port with pin numbers|left|frameless|PSP-1000 HPRM Port]]
{| class="wikitable"
|+
!Pin
!Signal
!Notes
|-
|1
|Mic input
|microphone signal, decouple with a capacitor to audio ground when using (sleeve of 3.5mm connector)
|-
|2
|GND
|Digital ground
|-
|3
|UART4 TXD
|PSP UART4 transmit
|-
|4
|nWakeup
|Ground this pin to wake PSP from standby
|-
|5
|VCC_2v5
|2.5v supply
|-
|6
|UART4 RXD
|PSP UART4 receive
|}

== PSP-2000 & PSP-3000 ==
PSP-2000 and PSP-3000's HPRM port is expanded to also carry video out signals. Serial signals operate at 1.9v on these models.
[[File:PSP-2000 Headphone remote port.jpg|alt=An image of the PSP-2000 headphone remote port with numbered pins|left|thumb|PSP-2000 HPRM port]]
{| class="wikitable"
|+
!Pin
!Signal
!Notes
|-
|1
|Mic input
|
|-
|2
|UART4 TXD
|PSP UART4 transmit
|-
|3
|DGND
|Digital ground
|-
|4
|Y
|Luma component video signal (green jack)
|-
|5
|VGND
|Video ground
|-
|6
|Pr
|Red / Luma difference component video signal (red jack)
|-
|7
|UART4 RXD
|PSP UART4 recieve
|-
|8
|VCC_1v9
|1.9v supply
|-
|9
|Video Det
|Video detect, 42k resistor to GND signals a composite cable
|-
|A
|nWakeup
|Ground this pin to wake PSP from standby
|-
|B
|Pb
|Blue / Lume difference component video signal (blue jack)
|-
|C
|VGND
|Video ground
|}