[Jacques]

Hi,

Does anybody know what the maximum current is one can draw from the 5V line of the Octane SCSI backplane (or the connector itself).

...or....Is there anyway to obtain 2.5A / 5V from the PCI cardcage frontplane connector.

(yes, I'm thinking of popping a RasPi3B+ in there to act as a mini server, remote desktop client for browsing and NFS store)

If I was on the O2 I'd try and hook it up to the Molex where the CDRom is.

Failing this I'll have to allow for an external connector.

[okonoko]

<QUOTE author="JacquesT" post_id="201" time="1526932774" user_id="104">

obtain 2.5A / 5V from the PCI cardcage frontplane connector

< 2A

[Jacques]

Thanks for the info, pity though.

Any idea if pulling that current from the frontplane in the PCI card cage is possible? Or should I just say fook it and do and external PSU? I'l like to keep it all in the box if possible...

[okonoko]

<QUOTE author="JacquesT" post_id="232" time="1527011743" user_id="104">

from the frontplane in the PCI card cage is possible?

Possible, but risky if your load exceeds 2A cause you might damage the LDO.
You might consider Atom or AMD Geode new boards. They eat 1.2A @ 5V.

Clock downgrading (when possible, but usually you sort it out by setting the PLL's register) is another option.
The power consumption of a RISC CPU is proportional to its clock.

<QUOTE author="JacquesT" post_id="232" time="1527011743" user_id="104">

Or should I just say fook it and do and external PSU?

It's a better idea, in my opinion, because it doesn't waste a PCI slot, neither an SCSI-SCA sled, and it's more useful if you consider that Octane eats electricity even when it's power-off.

Thus, you might consider an external box with a high-power relè that switches the electricity to the machine only when it's powered on and running. Inside this box, you can put a mini switching PSU for RPI, as well as an external hard drive, and what you need without the space constraints you are obliged to respect if you try to embed such a stuff inside the Octane's chassis.

[okonoko]

p.s.
I have a similar project on the way, feel free to contact by PM.

[Jacques]

When I have enough posts <E></E>

Thanks for the feedback. As I'm unlikely to run any PCI cards in the Octane (I don't have a cardcage) I may pop the 'mini-server' in the card cage space, fixed to a custom bracket that mimics the PCI card cage bracket. I can 'plumb' in a suitable power connection point as part of the new bracket / cover design. This way I can connect the SCB via a patch cable to the Octane's ethernet port. There may even be space to exhaust a little low profile fan to help extract any heat from the card cage area.

This whole idea started as I wanted to

a) be able to remote into a little server (~15W) for a modern browser that can connect via wifi to my router. The RPi 3B+ fits this profile well and is about £32;
b) is not a power hungry MacPro (I don't want to run the Octane and MacPro at the same time); and
b) most importantly, get rid of the cat6 cable dangling from my ceiling in my lounge. <E></E>

[GRudolf94]

Each drive sled on the Octane gets a fuse per 5V and 12V rail. If you pull the frontplane and pop off the HDD cage fan, you can see the fuse rating and figure out max allowed draw. Another option is to tap straight into the 5V PSU posts but I don't think that's the best of ideas.

Well, just a tidbit of info in case you do decide to run the RPI off the Octane's internal 5V