802.11ac SOWN Zepler
This is a project to build a new SOWN Zepler node that provides wireless access using the 802.11ac standard.
- Determine how mount antennas for SDRs.
- Get SDRs working with current firmware.
- Cover whole front of internal mounting plate with Velcro.
- Apply reverse velcro to SDRs and POE splitter
- Mount additional mounting shelf to IP56 metal box.
- We already have some M4 nuts/bolts. These are a bit smaller than ideal but it is fiddly to get nit onto bolt. Might use blue tack to hold nut in place and then try in bolt.
- Laser cut modified design of connector plate, as original had the following issues.
- Lightning arresters cannot be placed adjacently.
- The original design had N-Type connectors holes that were about 1mm or so too narrow.
- As plate is not metal we are not grounding connector chassis
- Tyler has done a redesign and has the spare acrylic from which the plate can be cut. Once we have a plate we are happy with we should cut plin round holes in the metal plate and use both plates (acrylic and metal) one on top of the other.
- Mount connectors to connector plate.
- Mount connectors plate to box.
- Fit some rubber washers to mounting bolts between box and external mounting plate for better waterproofing.
- Finish getting firmware working so both nodes and the SDRs work with the APU board running Debian.
- Do a fully assembled test of:
- 802.11n card
- 802.11ac card
This lists all the items we already have for building the new 802.11ac Zepler node.
- APU2c2 board
- APU case
- Metal IP56 box (240x190x90mm)
- 30GB MSATA SSD disk
- 16GB SD card
- 802.11n mini-PCIe card
- 802.11ac mini-PCIe card from an Archer C7
- mini-PCIe extender
- 802.3at PoE splitter (capable of providing 2A at 12v) (comes with power connector cable suitable for the APU2c2)
- 2 x N-Female to N-Female bulkhead connector
- 2 x N-female dust cap
- 4 x N-Female to u.Fl pigtail
- 2 x short (50cm or less) Cat5e network cables
- 2 x pairs of pole gripping brackets with 4 x suitable bolts and 8 x suitable nuts.
- 1 x 2mm Aluminium sheet to mount IP56 metal box to pole mounting brackets.
- 1 x 2mm Aluminium sheet with fastenings to make shelf inside IP56 metal box.
- 4 x small countersink screws to attach APU2C box to shelf.
- 2 x USB SDRs suitable for 2m band
- 2 x 25cm USB extenders with ferrite chokes (for SDRs)
- 2 x SMA-Male to N-Male
- 2 x Lightning arresters (up to at least 2.4GHz)
- 2 x Lightning arresters (up to 6GHz)
- 1 x Cross beam mounting bracket (found in cage 9)
- 2 x 2 metre N-make to N-male cables.
- 1 x 1.5m metre moulded (dark blue) ethernet cable (found in cage 9)
- 1 x Colinear antenna
- 1 x Discone antenna
- 1 x 1.5 metre Aluminium pole for crossbeam
- 1 x crossbeam mounting assembly
- Enough velcro to cover one side of internal plate of IP56 metal box.
- 4 x N-Female to N-Female bulkhead connector (Total cost £21.84 bought by User:Scorpia)
- 4 x N-female dust cap - Only 2 will be used (Total cost £8.97 bought by User:Scorpia)
- 1 x Ethernet Waterproof connector (Total cost £5.99)
- D-Link 802.3at PoE splitter (Total cost £27.48)
- Metal IP56 box (240x190x90mm) (Total cost £32.99)
- 2 x USB SDRs suitable for 2m band (Total cost £41.90)
- 2 x 25cm USB extenders for SDRs (Provided by User:Phil at no charge)
- 2mm aluminium sheet for building IP56 metal box shelf and mounting plate. (Total cost £13.99)
- 10 x M4 bolts, nuts and washers for attaching shelf to IP56 metal box (Total cost £2.99)
- 2 x SMA-Male to N-Male for USB SDRs to connected on the N Female bulkhead pass through. (Total cost £6.16)
- 2 x N-Male to N-Female lightning arrester. Should arrive on or after 27th March. (Total cost inc. delivery £38.06, additional £14.43 import duty and administration thereof)
- Acquired sufficient Velcro from Kirk, free of charge.
- 2 x N-type female to PL259 male adapters (Total cost inc. delivery £9.10)_
- TOTAL COST: £223.90 (N-type pass throughs and dust caps to be added).
- £166.74 on SOWN-Zepler budget £57.16 on SUWS mast budget.
Bought (awaiting delivery)
Nothing currently awaiting delivery
- May need 2 x filters for the USB SDRs
To make it easier to install and configure the SDRs, a 64-bit version of Debian 8 (Jessie) has been installed on the MSATA SSD.
Installing the Operating System
Netbooting is the easiest method to install debian on the APU board. This is because it allows for easy modification of the installation files to force the board to install over a serial cable rather than using a video output. The APU board we were using is a difficult one as it also has a graphics processor with no display connector. Hence, the installer tries to use this and we get no idea what's going on.
To netboot the board, I used instructions from this link. 
During the installation, select the following options at the package selection stage:
- DISABLE Debian Desktop Environment (extra overhead for a server device)
- ENABLE SSH Server
- ENABLE Standard System Utilities . Seemed like we could need them at some point.
Remember to install grub.
Check everything's up to date
su root <password entered during setup> apt-get update
If you used the guide I suggested above, you've now ended up with Debian 7 (Wheezy) installed. Let's update it to Debian 8 (Jessie) Now, edit /etc/apt/sources.list, replacing all instances of 'wheezy' with 'jessie' Then,
apt-get update apt-get upgrade apt-get dist-upgrade
Now, install a newer kernel. In this case, we upgraded to 4.9 from 3.2. I used this 
Edit sources.list to include backports
deb http://ftp.debian.org/debian jessie-backports main
apt-get update apt-cache search linux-image apt-get install -t jessie-backports linux-image linux-image-amd64
And now we're running a really recent kernel.
Now, add non-free to each of the items in /etc/apt/sources.list (I did this for the first two (jessie) and also the (jessie backports) entry)
Now to install the drivers for the Broadcom NIC
apt-get install broadcom-sta-dkms wireless-tools
It's likely time for a reboot now....
(Hopefully it'll come back up)
It lives! Let's just check it's running the new kernel we installed...
uname -r 4.9.0-0.bpo.2-amd64
Ok so the kernel upgrade broke the broadcom firmware. Install these things first and then reinstall the firmware.
Basically, install as many headers as you can, (sudo apt-cache search linux-headers) and it works
sudo apt install broadcom-sta-dkms
Now to install ath10k with associated firmware.
Configuring as a SOWN node
To be completed
The steps required to configure the system to work as a SOWN node should be saved as Puppet scripts, so that these can be reused if we want to build a second node or need to rebuilt this node after a failure.
The general day-to-day configuration should still be manageable through the SOWN admin system. Therefore, the configuration needs to include a script that can pull down configuration files to update aspects of the system, such as wireless channels to use.