[Dprglist] Roborama & wireless networking

[Mary Mathias]

Oh.. he also said lots of local hams, especially those doing emergency
communication, are working on it, so maybe we can find a local group either
there at DMS or on Carrollton to help?
~MJ

On Sun, May 13, 2018, 2:48 PM Mary Mathias <mjmmaker at gmail.com> wrote:

> Carl,
> I asked one of my old-time DFW Makers who taught HAM classes for us & he
> suggests starting here https://www.aredn.org
> for packet radio and mesh networking over ham frequencies.
> ~Mary
>
> On May 13, 2018 1:26 PM, "Carl Ott via DPRGlist" <dprglist at lists.dprg.org>
> wrote:
>
> Thanks to everybody who came to RoboRama yesterday - it seems that
> everybody had a good time, we met new visitors & old friends, and we had a
> well received contest!
>
> We also had Wi-Fi issues - leading to questions...
>
> Can anybody offer suggestions for the Wi-Fi issue some of us observed
> yesterday?
>
> The issue was that as the day went on, and more people surfaced in the
> Makerspace, the Wi-Fi environment went from almost tolerable to
> ***difficult for some - won't work at all for others***.
>
> This forced several of us to use personal access points - which definitely
> helped - at least for those using the connection more for telemetry than
> 'in the loop communication'.  However, I was not able to run at all due to
> apparently tight latency/jitter requirements, which became unmet as the
> makerspace filled up.  This becomes apparent for my robot when one video
> stream receiver (whatever Chrome uses) behaves much better and more
> consistently as the environment degrades (still ultimately failing), but
> another codec viewing the same stream (ffmpeg + whatever plug-in adapter
> RoboRealm uses for RTSP) fails much sooner - 'at the drop of a hat /
> network-packet' - completely breaking my control loop, yielding grumpy
> scowls and a very still and boring robot...
>
> My question is this - what options should I consider beyond the obvious?
>
> *The obvious options are*
>
> a) keep processing local, get the network out of the loop
>
> b) flip the personal access point an unused Wi-Fi channel
> ---> e.g. on 5 GHz
> ---> ie. requiring adding a 5 GHz dongle to R-Pi Zero W (depends on
> finding one with compatible driver)
> ---> or requiring swapping R-Pi Zero for e.g.R-Pi 3 B+ (with built-in 5
> GHz, entails considerably more hardware rework to existing robot platform)
>
> c) find an alternate radio strategy
>
> d) give up
>
>
> Currently, options a and d are off the table, and next steps focus on
> option b.
>
> *So my questions for DPRG land:*
>
> *1. for option b:* can anybody recommend an R-Pi Zero W compatible Wi-Fi
> dongle with 5 GHz?   If no better out there, I'm gonna try an older /
> slightly larger version of this:
> https://www.amazon.com/gp/product/B01MY7PL10/ref=ox_sc_mini_detail?ie=UTF8&psc=1&smid=ATVPDKIKX0DER,
> with what appears to be a R-Pi compatible open source driver recommended by
> the vendor...
>
> *2. **for option c:*  can anybody recommend something small other than
> Wi-Fi that can carry low jitter / low latency /  low video resolution
> (e.g. 160 x 120)  network packets, and interface cleanly to both R-Pi
> Zero and Windows?
>
> *3. **for option c:*  has anybody dabbled with network packet data over
> HAM frequencies?
>
>
> Thanks!
>
> Carl
>
> carl.ott.jr at gmail.com
>
>
>
>
>
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