KillianOla
Posts: 1
Joined: Fri Apr 14, 2017 1:55 pm

Pi Compute Adapter

Fri Apr 14, 2017 2:02 pm

Hi there!

I want to use the Pi Compute module in one of my projects instead of the Pi A+, so that I don't have to use any SD cards. I have just seen this:

https://www.kickstarter.com/projects/16 ... =user_menu

but this comes out in June. Does anyone know of anything like this available now?

Thanks!

GordonTGopher
Posts: 70
Joined: Sat Dec 01, 2012 11:25 am
Location: Letchworth Garden City

Re: Pi Compute Adapter

Fri Apr 14, 2017 3:44 pm

Not quite the same thing but https://www.raspberrypi.org/products/co ... -board-v3/ might be of use to you.

Gordon

fruitoftheloom
Posts: 19795
Joined: Tue Mar 25, 2014 12:40 pm
Location: Delightful Dorset

Re: Pi Compute Adapter

Fri Apr 14, 2017 4:16 pm

KillianOla wrote:Hi there!

I want to use the Pi Compute module in one of my projects instead of the Pi A+, so that I don't have to use any SD cards. I have just seen this:

https://www.kickstarter.com/projects/16 ... =user_menu

but this comes out in June. Does anyone know of anything like this available now?

Thanks!
The Compute Module requires a Base Board, so what ports or GPIO do you need exposed ??

https://www.element14.com/community/doc ... e-module-3
adieu

My other Computer is an Asus CS10 ChromeBit running Chrome Operating System.
HP Envy 4500 Wireless Printer supported by HPLIP software in Raspbian Buster.
Raspberry Pi Model 2B v1.1

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CarlRJ
Posts: 599
Joined: Thu Feb 20, 2014 4:00 am
Location: San Diego, California

Re: Pi Compute Adapter

Fri Apr 14, 2017 5:42 pm

FWIW, Raspbian got a lot better with respect to microSD card troubles a while back when they shifted /tmp and some of the "behind the scenes" filesystems over to tmpfs. That cut down on a lot of second-by-second write activity to the card. Nearly all my Pi's run 24/7 and I haven't had a card failure in the past year or two.

There are also alternative Linux distributions that boot entirely into memory and then treat the card as read-only, which entirely bypasses the wear problem (that Kickstarter mentions microSD cards having a limited number of read/write cycles - this sounds disingenuous, the cards certainly have a finite upper limit to the number of write operations, but I've never heard of one wearing out from reading).

As well, some folks also boot from the microSD card (an inherently read-only process) but then keep the root partition on a USB flash drive, which still uses the same technology, but often times are more robust.

All of which to say, if you want a Compute Module for other reasons, by all means get one, but if you're "merely" worried about microSD failures, there are other less expensive/elaborate solutions that might work for your project.

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rpdom
Posts: 14451
Joined: Sun May 06, 2012 5:17 am
Location: Chelmsford, Essex, UK

Re: Pi Compute Adapter

Fri Apr 14, 2017 6:26 pm

I don't recall ever seeing /tmp as being on a tmpfs on a standard Raspian install.

I do remember that Debian tried it a few years ago and reverted the change after a lot of prople complained this left them with a /tmp that wasn't big enough for many common operations.

W. H. Heydt
Posts: 10321
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Pi Compute Adapter

Fri Apr 14, 2017 6:56 pm

As note, as regards limited write cycles, that that applies to eMMC flash as well. Granted, the eMMC module should have more write cycles than an SD card, but it can't be easily replaced the was an SD card can. It's pretty much a "you pays your money and you takes your pick" situation. I will say that the CM+carrier A+ is pretty clever, though. At the same time, I think the launch of the Pi3A will pretty much eclipse it, though. (I may back the KS campaign anyway as I think it's neat idea and a B-series equivalent would also be a neat idea.)

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CarlRJ
Posts: 599
Joined: Thu Feb 20, 2014 4:00 am
Location: San Diego, California

Re: Pi Compute Adapter

Fri Apr 14, 2017 9:27 pm

rpdom wrote:I don't recall ever seeing /tmp as being on a tmpfs on a standard Raspian install.
Ack, you're right - /tmp isn't on tmpfs, it's just /dev, /run, and a bit of /sys. I was crossing wires with FreeBSD where (at least back when we were running it in production) /tmp was on a special filesystem (actually, using part of the swap space, IIRC - anyway, things left there didn't survive a reboot). At that time, the rule was, if you wanting a _big_ temp file, put it in /var/tmp, as /tmp was expected to be fairly small (but also fast). But then, /, /usr, /var, and /tmp were all separate filesystems anyway.

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