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I built one! Arduino Leonardo and a light dependent transistor:

https://github.com/willmuldrew/lagmeter

(It attempts to do a few other things but it’s best for measuring keyboard event to screen update latency)

There used to be a coffee shop opposite my office that had a pull handle on the push side of the double doors. The right hand side doors were also often locked. I once sat at the nearest table to the doors and watched a dozen people pull then push on the right door, then pull and finally push on the left door, and often end up visibly aggravated by the time they got in and joined the morning queue!

The next day my debugging instinct kicked in, I bought some PUSH stickers and did some covert guerrilla ergonomic stickering. Problem solved and it made me smile every time I went past that cafe!

I had a look into how Jamulus works under the hood. It’s more of a hub and spoke model with the central server receiving, buffering and resending the stream out to each client. This has some advantages (kinder to bandwidth especially as the number of clients increases) but it does mean that there are two sets of recv buffers (server and client) which need to be deep enough to avoid too many missed packets due to jitter. My personal experience was that even when running it all on a lan I couldn’t get much below 16-20ms with an ideal near zero latency network. Once you add in geographic latency and internet jitter then it goes up considerably.

(Full disclosure: Weepy and I played with Jamulus then he had a crack at building sub.live)

Wifi might not be too bad, though it can spontaneously degrade badly if you get interference. Not great in the middle of a jam!

I see 3ms ping times between my friend and I on opposite sides of London, though we’re both on pretty decent broadband tech (me gfast, him some fancy hyperoptic plan). IIUC there are some ADSL technologies that add some minimum latency floor of 10+ ms. However the long distance stretches of backbone fibre shouldn’t necessarily add too much latency - e.g 100km of fibre at 2/3rd speed of light is an additional 1ms on your (two way) ping time

It’s worth remembering that sound takes 3ms to travel a metre. If you’re standing a few metres away from a drummer then the round trip time is already pushing 20-30 ms of latency and yet you can still play together in a rehearsal room

There’s a great video here that goes through all this - the gist is that USB keyboards specify what polling rate to use, 1000hz for the best ones, maybe 125hz for the cheaper ones. An interesting thing about ps/2 is that even though it doesn’t have to wait for the keyboard to poll it transmits data at much slower speed than USB (khz vs mhz) which somewhat offsets the advantage it gets from being interrupt driven

https://m.youtube.com/watch?v=wdgULBpRoXk

edit: ah, sorry, I see someone's posted a link to this video already!

It used to make me sad that by the time my kids were old enough to cycle up big mountains, I might be too old/unfit to join them... but the massive growth in the last few years of electric bikes (mountain and road) makes me really excited that I actually might be able to keep up. I don't know if e-bikes would help given your condition, but if you haven't tried one, it might be worth a shot - they're amazing

I embarked on a fun lockdown project retrofitting our traditional doorbell (which runs off a 12V AC transformer in the basement) to generate MQTT messages for logging and to trigger notifications (phone, pop-ups on my workstation, sonos noises, hue lighting flashes etc). I have the same problem of not hearing the front door from my office in the loft.

I ended up with an ESP-32 module connected to the house wifi, and an opto-isolated circuit to trigger it from the doorbell wiring. It sits in the basement where it's easy to give it power from a USB power adaptor.

Of course, the irony was that it was only after I'd lost a few days going down this particular rabbit hole that I discovered that almost every visitor (and especially delivery drivers) uses our door _knocker_, rather than the doorbell since it's much more obvious! The next project may be to electrify that, or mount a vibration sensor on the door!

I think they do - 5G seems to have the prospect of some realtime low latency guarantee features (though I don’t think it’s rolled out yet). With this in place and an RT audio device you could build an all in one remote jamming box without having to insist on wired internet or deal with the wifi jitter. Currently the user’s network is often the bane of things like Jamulus that try to do this in software + your internet connection

I could look at this in full-res if only I had a multi monitor setup with a million 4k screens!

Me too - jamming at about 15ms lag with Jamulus felt really natural. In fact after months of talking to other people through zoom, just chatting with my friends with low latency, high quality, and without the auto processing/muting that zoom seems to do, was amazing. Conversation just flowed back and forth better!

There’s a bunch of similar bits of software but none of them are super welcoming for the less technically inclined. I guess that the experience is often going to be limited by network performance (specifically jitter and loss on UDP) so it’s a challenging thing to make super slick/consistent. I think that low latency 5G with latency guarantees might help solve it when its widely available though.

I think that’s about a 1000x overestimate - about 1Ah * 1.5v * 3600s = 5400 J - that’d lift 540kgs up a metre

(Maybe double that for an alkaline one)

Something like this would be my total nightmare!

https://vimeo.com/166807261

With lockdown keeping me at home, and having to RDP to work over a VPN, I've gone quite far down the rabbit hole this year experimenting with low latency keyboards (1000Hz USB polling, configurable debounce times), gaming mice and high refresh rate monitors (125Hz+), all to try and make my remote experience feel more local.

The threshold for me (and most people I think) is about 110ms between key strike and something appearing on the screen before something feels non-local and disembodied... which is good because I found I could get down to ~40ms local response time on a decent windows box. My 2015 macbook is about ~120ms for the terminal app.

That leaves 70ms latency budget to play with which can accommodate the the RDP overhead (~50ms) and the network hop (~10ms for me).

This whole journey started with me wondering if I should pay a small fortune for a better network connection, before I realised that most of the latency was in my keyboard and monitor!

I even built a Arduino Leonardo gadget to measure the lag systematically and some pcap software to spot the RDP packets on the wire. The code's pretty shoddy but it does the trick! You can see it and an example result with RDP here:

https://github.com/willmuldrew/lagmeter

Another big factor in the experience is jitter - so it's a good idea to ensure everything is plugged in if you can. Mice, keyboards and ethernet.

In essence, even if you have to RDP/remote into work, potentially you can still make it feel pretty local - don't give up hope!

Our 3 year old had a total meltdown yesterday because I brought him his toothbrush and toothpaste, but in the wrong hands! When you’re tired it’s so easy to take this stuff personally and then all of a sudden you remember that there’s this little person whose brain is catching up with their emotions and suddenly it’s a lot easier to be sympathetic, philosophical and fascinated, even by the tantrums!

After watching Zach Hartwig's youtube video [1] which culminates in talking through the ARC/SPARC approach to building more compact tokamaks (that don't require epic levels of global political collaboration, multi-decade planning and financing like ITER) I've been seriously considering a career change just to try and get involved! (There's a more focussed video on the Commonwealth Fusion Systems approach here [2])

As a physicist, turned developer, turned tech manager based in the UK I'm not quite sure what an opportunity looks like, and whether the right approach is to bash the plasma physics books, or wait for a more tech-orientated role to crop up.

I'm also really interested to know how these startup-esque companies are all going to handle their intellectual property now they're private enterprises - are their individual breakthroughs all going to be kept deeply secret (and vanish if/when most of them eventually fail) or are they all going to be frantically cross-licensing their discoveries so that in aggregate we don't lose out of the benefits of collaboration. According to A Piece of the Sun (by Daniel Clery) the early days of fusion research were hampered by international secrecy - things really started moving when researchers persuaded their governments to open up and let them work across borders.

[1] https://www.youtube.com/watch?v=L0KuAx1COEk [2] https://www.youtube.com/watch?v=KkpqA8yG9T4

Milton Keynes? :)

I chuckled/was staggered when I heard that the power density in the Sun's core is approximately the same as a compost heap! (albeit a rather large one...)

https://en.wikipedia.org/wiki/Solar_core#Energy_conversion

Martin Hairer also has a software company making audio editing tools (https://hairersoft.com/) - I love this Fields medal comment in the middle of an otherwise mundane support forum thread about MacOS compatibility! https://hairersoft.com/forum/viewtopic.php?f=1&t=2574&p=8222...