forums.ps2dev.org

i0e192 · Joined: 21 May 2005 Posts: 2

So if we use pins 2 and 5, can we actually use the PSP's power to power something? Like a small transmitter or something?

I am trying to create some accessories that will take up 20mah, and I am not sure what's the best way since I don't want to introduce auxiliary battery packs.

Any help is appreciated on this. I had though of using the USB, but it seems the port cannot give out power. Am I right on that assumption?

Cogboy · Joined: 19 Jan 2005 Posts: 45

not sure about the usb, but you might want to look into the remote port.
there was a bit of disscusion on this port a while back.
you can find it here: http://forums.ps2dev.org/viewtopic.php?t=986
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Guest · Posted: Sat May 21, 2005 4:53 pm Post subject:

In theory the USB port can give power but I believe it must negotiate it with another USB device to turn it on.

Otherwise check the remote port.

Fabre · Joined: 22 May 2005 Posts: 18

Are you saying the USB devices must communicate before the slave device receives power? Lots of USB powered devices (USB lamp, DS charge cable, etc) require nothing more than a power and ground cable connected to two wires on a USB plug to receive power.

cheriff · Regular Joined: 23 Jun 2004 Posts: 262 Location: Sydney.au

But the usb port on the psp is configured as a slave, for use when connected to pc, ps2/3, etc. Not sure that there's any provision in the usb spec for a slave device to provide any power, I'd say its some extension to the protocol, much the same way that the psp kb is said to be configured as a host, to enable it to speak to the psp, with some clever trickery to get it to act to the contrary.
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Techit · Joined: 22 May 2005 Posts: 13

Off topic but any way to be able to rig a cable or something to read off of a say external USB harddrive or MP3 player? That would be really nice for on the road. Just a thought.
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sq377 · Joined: 11 Apr 2005 Posts: 87

I would think it would be possible now if someone took the time. Someone would have to write a homebrew app to access the usb/remote, they could access the drives, but i would imagine they may have to write their own players. Something could be probably written to copy from the external to the card, but other than that it would have to be third party.

But dont take my word for it im nub :D

Techit · Joined: 22 May 2005 Posts: 13

I think some of these ideas will need to wait till after 1.5/1.51 is cracked.
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Fabre · Joined: 22 May 2005 Posts: 18

Who says it's only a slave device anyway? Aren't the keyboard/etc meant to plug into the USB port? And even if it is only meant to be a slave device, there are ways of using it as a master device - GP32 was only meant to be a slave device, but with GP32 Linux, you can use it as a master device.

cheriff · Regular Joined: 23 Jun 2004 Posts: 262 Location: Sydney.au

It was mentioned by a sony employee at bp05 in the psp seminar. Keyboard/etc are meant to plug into the USB port, but they're designed to be hosts so there still is only 1 host / slave combo the bus. I guess it would use software based tricks to get it to act the other way such as found in linux. This how i heard and interpreted it, and has been previously discussed in another thread.
All i'm, saying is that from a hardware standpoint psp is a slave, and unless you know these software tricks they it's probably more difficult than just connecting up to the pins. Even with normal usb devices, they have to negotiate to be able to draw more than X amount of power, and i doubt its tha same on psp.
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Guest · Posted: Sun May 22, 2005 5:54 pm Post subject:

Yeah. You want to make sure that the PSP doesn't think it wants to try to draw power from the device you hook up to it, unless of course, thats what you want. :P

i0e192 · Joined: 21 May 2005 Posts: 2

So in firmware, it may be possible, right?

With the remote control, is there any confirmation that the power from that can be used? Can it provide 20mah?