Power output from DC serial slot?

[runkthepunk]

Hello all

Just a quick query:

I presume that there is power taken from the serial port on the back of the Dc when using an SD card reader for dreamshell etc.

My question is: Is the power output the same power/Voltage as a USB connection? I ask as I have a USB powered device that I want to power via the DC using the serial output. If anyone has a schematic of the pin outs that would be great too or just which pins are the power outs.

Thanks

Rob

[LoveGHz]

USB is 5 volts. I'm pretty certain you can find a 5 volt line inside the Dreamcast though.

[runkthepunk]

Hey thanks for the schematic!

3.3V thats a bit annoying maybe I will give it a whirl anyway and see if there is enough power.

Probably a 5v supply in the DC for sure but i didn't want to open up/solder anything to the board etc

Thanks again

Rob

[-=FamilyGuy=-]

Hey thanks for the schematic!

3.3V thats a bit annoying maybe I will give it a whirl anyway and see if there is enough power.

Probably a 5v supply in the DC for sure but i didn't want to open up/solder anything to the board etc

Thanks again

Rob

You could sqeeze a small wire in the connector that links the power supply to the motherboard if you don't wanna solder anything, there's plenty of room there. I used to do that on a ever-opened dreamcast to test leds...

[Chilly Willy]

USB is 5 volts. I'm pretty certain you can find a 5 volt line inside the Dreamcast though.

The ORIGINAL USB 1.0 was 5V. It's been 3.3V for a LONG time. That's a problem with certain products which use a USB connector for power - modern USB ports have too low a voltage for them to work right.

[josiahgould]

The ORIGINAL USB 1.0 was 5V. It's been 3.3V for a LONG time. That's a problem with certain products which use a USB connector for power - modern USB ports have too low a voltage for them to work right.

I'm sorry, I have to disagree.

USB still outputs 5V @ at least 500mA. The problem is that people plug in a dozen devices, a hub or two, and the voltage drops. USB 3.0 I believe can even output 5V @ 1.5A for charging. With every device you plug in you usually get a voltage drop.

[synrgy87]

I'm sorry, I have to disagree.

USB still outputs 5V @ at least 500mA. The problem is that people plug in a dozen devices, a hub or two, and the voltage drops. USB 3.0 I believe can even output 5V @ 1.5A for charging. With every device you plug in you usually get a voltage drop.

this is correct.

and 5v can be taken from the pins that connect the power board to the motherboard, quick and easy people have used this for led mods etc so its fine.

[Chilly Willy]

That might be spec, but I've got two computers that output 3.3V with nothing attached, and I've spoken (over forums like this) with at least a half dozen other people who will tell you the same. It's more common than you think.

[splith]

If you've got 3.3v output then you've got a dodgy/cheap USB host because 3.3v is NOT USB logic level, it is 5v.

[Bad_Ad84]

Agree, USB is 5v. 3.3v will not work.

I suspect your ports have just powered down until handshaking has been done or similar. Its still 5v when connected to something,

[synrgy87]

if you connect a 5v LED to the usb port it should light up nice and bright, as Bad_Ad84 says, it's probably a power saving mode / power state until the ports are in use. 3.3v wouldnt cut it for running USB devices

[Calpis]

3.3v is NOT USB logic level, it is 5v.

USB does use 3.3V "logic level" for signalling (always has). Most USB-powered devices have 3.3V LDO regulators for this purpose, so if the 5V rail wasn't 5V they'd fail.

[Chilly Willy]

Well, I'll take you word for. Might be why I've had "weird" things happen with my USB. Just my luck to get dodgy ports. :(

[alex81]