8 Leaf Pi Zero Bramble

Description

Having been one of the lucky few to get to Barnes & Noble soon enough, I scored 2 Magpi #40 issues. 1 is getting saved, and the other one is my first bramble leaf (my sister-in-law got me a third one YAY!)

So, here's my attempt at making a slotloading supercomputer. This first iteration will just be the "mechanical setup" while I design the power distribution and how to best mount the ethernet.

I think this would lend itself well to being routed from acrylic for a better visual punch.

Details

I always wanted a supercomputer, and I was one of the lucky few who was able to get my hands on more than a single Raspberry Pi Zero.

I decided that for the price of $5 per leaf, the family CEO could NOT refuse my addiction this time. Besides, she just got me a 3D printer and, really, I can only print so many geared hearts...

I had seen a couple of zero supercomputer shells in Thingiverse and thought "Wow, these could really be small and THEN I started remembering my days as an SA and all the hot-swap drives I had to, well, hot-swap. I decided then and there to build a slot-load case (8 slots for this one), WITH power distribution AND a way to hook up ethernet. Besides, who wants a Delta Burke pantsload of wires coming out all over the place?

UPDATE: I've had to switch to wifi dongles. The usb ethernet adapters I bought turned out to be duds. I couldn't even harvest anything useful!

I try not to use Microsoft, out of principle, but, one thing they got right is the free STL fixing service on AZURE. All my work has been with free or really cheap tools, and the quality of a finished product can sometimes reflect the costs incurred. Luckily Azure provides a good STL cleaning service that has so far, never steered me wrong. Every time the XYZPrinting software has messed up an export to the .3w filetype, I have been able to go to AZURE and get it fixed such that I could successfully print. Here's an example. In the picture, there should be 2 distinct Models on the same printbed, but if you look in the middle, you will see they are connected. AZURE can fix that, though I don't understand why it removed the brim from the other one...

Files

Bramble Box - 8 SLOT.zip

DONE! This is a pre-designed 8 slot box for Raspberry Pi Zero

x-zip-compressed - 2.05 MB - 02/22/2016 at 03:29

Download

Bramble Box - BOTH.zip

Both the 8 SLOT and MODULAR Bramble Boxes are withn this file.

x-zip-compressed - 2.24 MB - 02/22/2016 at 03:29

Download

Bramble Box - MODULAR.zip

DONE! This is a pre-designed modular Raspberry Pi Box, made to grow as your collection grows.

x-zip-compressed - 193.01 kB - 02/22/2016 at 03:29

Download

Bramble Box- FINAL.skp

Final Version. Sketchup format

SSEYO Koan Play File - 4.91 MB - 02/18/2016 at 05:35

Download

Bramble Box- FINAL.stl

This is the final design that I will work from for now on.

Standard Tesselated Geometry - 168.17 kB - 02/18/2016 at 05:34

Download

Components

1 × 3D Printer with PLA filament To build the frame and chassis for the bramble

1 × mini-ITX PowerSupply and its matching receptacle 5v x 20 Amps yo! And 12V too...

1 × 10/100 switch Old Netgear

3 × Raspberry Pi Zero Compute Leaves - I have 2 available for computes. I can't give up the 3rd, It's staying in the MagPi #40 plastic wrapped with the mag!

1 × Raspberry Pi Model B Yeah.... The original dog. This will have CAT 5 ethernet with a WIFI private DHCP network for the compute leaves

Project Logs

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In-Laws rock!
txdo.msk • 10/05/2016 at 17:05 • 0 comments

Been a while since I could work on this!
Last month Microcenter had a special and enough stock, that my inlawz got me 6 Zeros for a grand total of $6!
8 leaves for $16 bones, yo!
SWEET!
Nice...
txdo.msk • 03/18/2016 at 04:14 • 0 comments

couldn't take a decent screenshot from my tablet's SSH client, but I figured out how to copy and paste from it. Check out this uptime! And they're all on wifi dongles and staying cool.
The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.
Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Mon Mar 7 05:31:02 2016 from android-de248ee545a683f6.home
mpi_user@rpi0:~ $ mpiexec -f machinefile uptime
04:10:12 up 15 days, 5:50, 1 user, load average: 0.00, 0.01, 0.05
04:10:13 up 15 days, 2:39, 0 users, load average: 0.00, 0.01, 0.05
04:10:13 up 15 days, 2:39, 0 users, load average: 0.00, 0.01, 0.05
mpi_user@rpi0:~ $
Home stretch!
txdo.msk • 03/09/2016 at 01:13 • 0 comments

Well, my 3D printer's hotend went belly up, so, I guess I'm going with my first design, the 8 slot case. The replacement hotels won't be here for a couple weeks and so, I can't do the top half of the modular case. The STLs are good though.
I ran some numbers and talked to a few people about my power supply, and decided to use buck converters on my 12v line from the ATX supply. I just can't take a chance of blowing up my Zeros what with the supply being decimated.
I'll finish it out by putting some lm2596 bucks on a protoboard and flying it up.
Bummer, Dude...
txdo.msk • 03/05/2016 at 19:33 • 0 comments

I am kinda bummed about the Zeros not being available for a while. With the Pi 3 coming out the .org is taking away from zero production to keep the Pi 3 going. So, this project will be finished a little early with just 2 zero leaves and a model 1 As the head.
:-(
It DOES leave the door open for an EVEN BETTER cluster project.
I DID IT!!!!
txdo.msk • 03/02/2016 at 22:42 • 0 comments

WOOT!
I got the basics down!
It all came down to getting the SSH-KEYGEN key swapping down right. There are some slight miscues from the articles I used as a basis, and I will be updating everything in due time and with more explanation to make things less confusing than what I have been thru. First, I will connect my second Leaf and set it up the same way and test it out though.
Family duty
txdo.msk • 02/29/2016 at 20:37 • 0 comments

Gotta do the family thing. No project work. In a nutshell though, the case is ready. Getting MPICH2 working with NFS on Raspbian is a lot harder than I thought. That's what I'm struggling with. Well, that and getting cheap Realtek knockoffs to permanently take a MAC address so I can pull up my NFS share automatically (can't with wifi) at boot up.
A little Script Fu
txdo.msk • 02/27/2016 at 03:59 • 0 comments

So, I'm also just going to put in a few safeguards against bad connections, like using ifup.
Also, I will assume that at somepoint I will get NFS automounting but in order to forge ahead, I am going to be writing a little script at the head of the cluster. One of the things it will do is pass commands thru the ssh login. Here's an example:
ssh pi@bramble-1`sudo mount /mnt/nfs`
That of course, will mount the SD card I shared out from the head, but the command will be run as if it were pi and inside the compute node. And I JUST got done testing, and the NFS connection is persistent even after logging off.
Just so you know, stuff like the above is what can allow you to rapidly deploy and test multiple systems at once. Well, almost at once. AND WITHOUT USING PARALLEL PROCESSING. There's a lot more involved with this, i.e. coordinating variables, checking status, etc. I did this exact thing years ago and loved every minute of it. I think I still have some old CDs around that had the beginnings of it.
Huzzah!!!
txdo.msk • 02/27/2016 at 02:57 • 0 comments

I got NFS to work correctly so I could consistently CLI mount the SD Card I shared out. I even verified by using the following bash command at each leaf:
echo $HOSTNAME > /mnt/nfs/$HOSTNAME
Then I screwed one up by troubleshooting the inability to automount the NFS share at bootup. Meh. At this point, I think maybe I'll just image the still working leaf and write it to the non-working one, then go thru raspi-config and rename the host back. I don't feel like dealing with cables.
I forgot to mention that I'm currently using wifi, and that may be the problem with automounting.
Yeah, I think I'll do that, then make sure I can run MPI tests, THEN try and figure out the problem with the RJ45 dongles.
OMG, I hate NFS
txdo.msk • 02/26/2016 at 05:42 • 0 comments

took forever to get the network interfaces to work, then another forever to get the Bramble head to share a directory. I did something wrong g and now NFS clients can't write to the share. I'll tackle that after work when I get home. I gotta get up in 3 hours!!!
Sigh...
Drudgery - Part Deux
txdo.msk • 02/25/2016 at 17:49 • 0 comments

So here I am with super-sized egg on my face. 5 hours later, my SD card finished getting read, I'm concerned I've done something wrong, only to find out my card has been in a USB 1 CONNECTOR!!!!
Some quick research tells me the back of my Linux box has USB 3, which is backwards compatible. Fast forward 10 minutes and a "DD" write of 16gb is almost finished.
SMH
:-$

View all 52 project logs

Build Instructions

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Step 1

8 SLOT BRAMBLE

For the 8 Slot STL, use your favorite slicer to create the files to print.

If you look within Sketchup, the 4 objects closest to the junction of the XYZ axes are all you have to print. The ones obviously for the Pi Zeros (Leaf and Cap) just get printed 8 times. The other two (rails and sides) get printed 2 times. There shouldn't be a lot of cleanup except for removing the brim after the print.

Glue up the mating blocks with super glue, so that the rails are top and bottom and use some blocks and weights to keep them lined up while the glue sets.

A Raspberry Pi Zero will JUST fit inside the fence of the Leaf and the slotted cap is a tight press-fit. It ain't coming out.

Step 2

MODULAR BRAMBLE

The corner pieces are the ones with the one taller wall and the corner slot. Print those twice. They can flip 180 degrees to be top and bottom corners. They are very tight in the slot and are ideal as walls when you fit a leaf in them: if a leaf is to be a wall and a compute module, you will need to cut into the corner wall where the WIFI dongle would go or solder a usb - ethernet module). The dovetails WILL require cleanup, but will eventually slot into each other. I designed the dovetails so there is only one way to connect.

The rails for the middle Zeros are designed to simply print twice for top and bottom.

Step 3

Install a known working wifi dongle by sticking in a USB OTG converter into the plug-in of the dongle.

Slot in an SD card that has been loaded with a Raspberry Pi (not Pi 2!) image that has SSH server available. Power up the Zero and run a scan on your network to find the new computer.

SSH into the computer and start configuring for clustered computing.

Discussions

txdo.msk wrote 11/08/2016 at 14:38

let me rephrase that. I think using the TX and RX off GPIO would be the slowest way. I intend to feed power into GPIO, but solder an adapter to use USB OTG. Once I have a good common setup, I'll benchmark and then use all common methods, to include full GPIO and compare.

Are you sure? yes | no

txdo.msk wrote 11/08/2016 at 13:58

that's actually what I will be doing. Although, I will have to redesign the case to allow wiring better. I haven't started the project on Hackaday yet, but I am planning a giant D20 dice with 20 zeros in it (& room to grow), but have decided that the easiest way to work with ATX, IS to go thru the GPIO.

Are you sure? yes | no

warhawk-avg wrote 11/08/2016 at 09:57

Could you come off the RPI0's headers, solder 5vdc, ground, and tx and rx data (pins 4,6,8,10) respectively (on recovered USB cords (red, black, white, green)), then tie into a USB hub of sufficient size, power the USB hub with 5vdc from an old throw away ATX powersupply?

Are you sure? yes | no

8 Leaf Pi Zero Bramble

Description

Details