[Mesh] Hardware for Study

[Yardena Cohen]

Hi Martin,

Sorry your message is getting through a week late. Our mail server was
down. We appreciate your generous offer very much and I hope someone
more involved with the mesh project can get back to you soon!

Best,
Yar

On Thu, Dec 5, 2019 at 2:23 PM Martin Kennedy <hurricos at gmail.com> wrote:
> Hi there folks,
>
> After years of learning a bunch of stuff off of mailing lists I've
> started working on using them. I want the messages I send to last and
> be referred to later on, so here's a random reply in a mailing list.
>
> For cheap hardware there are many great opportunities with
> end-of-life'd enteprise stuff. Brands like Meraki and Aruba require a
> license to run, which often means that large lots of hardware suddenly
> become useless to the original purchaser and are sold for less than a
> penny on the original dollar. When you combine this with the fact that
> a lot of ath10k and ath11k hardware has usability issues, the
> advantages of sticking with slightly older hardware become obvious.
>
> I have been stockpiling lots of Meraki MR16, MR18 and MR24. Was able
> to purchase about 250 MR16 for about $700, and trivial quantities of
> the latter for about $6 and $10 apiece for testing. All hardware has
> gigabit PoE (active or passive); the MR16 has 2x2 an and 2x2 bgn
> (AR9220, AR9223); the MR18 has 2 x 2x2 abgn (AR9582) and one 2x2 bgn
> out of the SoC, and the MR24 has 3x3 an and 3x3 bgn -- notably using
> mini PCIe slots rather than integrating them into the board, see board
> images here:
> http://en.techinfodepot.shoutwiki.com/wiki/Cisco_Meraki_MR24
>
> My suspicion is that the MR24's PCIe slots can be used with pretty
> much any mini PCIe cards (as long as they don't require the USB-side
> of the slot). This means we can stick, for example, Compex WLE900VX in
> them -- 3x3 abgn/ac cards with decent power and laughable
> affordability ($20/pc in single quantities). These run ath10k and are
> known to be OK to run in VHT-IBSS - after all the Archer C7 uses these.
>
> Flashing with OpenWrt is doable for all of these regardless of
> firmware revision; riptidewave93 has done most of the work porting
> these to OpenWrt. They have serial headers already on them, so for the
> MR16 you just pop it open and plug in and power it up (I wrote a
> script to automate it here:
> https://github.com/btvmeshnet/hardware/tree/master/platforms/Meraki/MR16/flashing)
> -- for the others you have to rebuild uBoot and reflash using a flash
> clip ... but my point really is, these routers can be obtained in
> bulk, have PoE so they can go anywhere, and have ath9k-based hardware
> so "just work with mesh no matter how you want to use them".
>
> Here's a lighting talk as done by Yurko of Tomesh:
> https://ournetworks.ca/livestream/?m3u8=live-2019-09-22.m3u8&from=QmWyL7hcue5a8PbmPRjbLSrmtQUWxV4akTuSQtu66SugmX
>
> I have a modification for the MR16 so that they can use external
> antennas - it's quite simple, just drill two holes for U.FL-to-RP-SMA
> pigtails in the two bottom corners and then screw in two pigtails from
> the inside. The internal U.FL connectors are attached to both the 2.4
> and 5GHz chains (this is why the internal radios cannot be used on the
> same frequency). At that point, you just attach two external dual-band
> antennas (or whatever else you want to stick on them).
>
> I am happy to write up much more complete guides for all of these
> things (I encourage EVERYONE to link whatever they write up into
> techinfodepot, as it is where many people who get into hardware go and
> learn). I am happy to flash and box up and ship 10 x MR16 + 5 x
> gigabit PoE injectors + 1 x USB-to-TTL cable if you folks can make use
> of them. I am happy to send folks TTL cables for free if they need
> them (you can also do this work with any Raspberry Pi). Quite frankly,
> to put them all to good use I would be happy spending all of my free
> time buying, modifying and shipping these out in exchange for my parts
> and labor cost (probably $8-$10 per MR16); my goal is to erase all
> barriers to reusing this hardware, as it is cheaper than dirt, tougher
> than nails, and is PoE-capable out of the box.
>
> I also see many more opportunities out there - like RTL8812AU (see
> aircrack-ng's repository for the driver) for
> very-high-throughput-point-to-point at low cost. I really would like
> to improve community knowledge of hardware so that those who have the
> most time and the least funds can gain and share knowledge of these
> things, which should (in theory) continue to improve access to
> hardware for everyone (because there are more interesting problems to
> solve than hardware).
>
> Sorry if this email is exhaustive. I don't see any good single place
> to collaborate on this so I'm doing a bit of a thought dump. Would be
> very happy if I found a good way to link together communities better
> as it took me years to do all this info discovery (did not know
> Sudoroom had a mesh mailing list until now).
>
> For hardware information in general I have been hoping to have
> consolidation, but since wikidevi.com has come down and is being
> migrated to techinfodepot, the new place for hardware info is here:
>
> http://en.techinfodepot.shoutwiki.com/wiki/Main_Page
>
> Let me know if you can use the box of Merakis; happy to send at no cost
> if I have a destination.
>
> - Martin Kennedy