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Wisdom about Covid
Tag: covid19
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Five days of Mondays…
And two Sundays. Poetic, isn’t it?
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1080p webcam for Zoom for $40
Fact 1:In the Covid-19 pandemic, we’re all on Zoom et al quite a lot.
Fact 2: Apple webcams are 720p resolution and quite low quality.
Fact 3: Nerds want to be helpful.
Consequence one: Good webcams are sold out universally.
Consequence two: The people behind the cheap and awesome WiFi webcam brand Wyze have written custom firmware to convert a wireless security camera into a very decent USB 1080p webcam. And it’s free.
Hardware requirements
- Wyze webcam v2 – vendor, or Amazon. $26 bucks as of today.
- 8GB or so micro SD card. You might have one around if you use Raspberry Pi. I bought this two-pack of overkill 32GB cards, since that’s a useful size for Pi project. $14.
- USB3 A to A cable. These are unusual and I had to order one. I bought a two pack so I can have a spare. $12, and cheaper versions exist. Note that your computer needs to have a USB3 port with an A plug – I’m using the one on my LG monitor.
Flash the firmware
Instructions are here on their site – TL;DR is to unzip the download and copy demo.bin into the root directory. Power up holding reset for five seconds. Pretty do-able even for the less technical.
Results
There are two Wyze cameras, basic or a $35 pan/tilt/zoom. I already had two of each, because at $20 to $35 each, they’re in my hobby budget and have been delighted with ’em. I chose the base camera as I see no use for PTZ.
Here’s the built-in webcam from my MacBook. It’s the 2018 15″ model, my work computer.
Now here’s the Wyze:
Color is a bit off, but resolution is a huge amount better. it’s also wide-angle, with strong curvature at the edges.
I was just in time for a Zoom birthday party.
Why yes, my family does look sharper than everyone else. And wide angle was perfect for this use. Sometimes you get lucky. You can kinda see my low-rent mounting:
I’ll leave it that way for now, as it makes it quick to move around and try other lighting.
Overall – recommended. Pretty cheap, the parts are versatile, and when this ends you just re-flash the camera to get back to a nice smart camera/IoT device.
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Six feet is the wrong model
A friend sent me this paper on Arxiv.org – “A physicist view of the airborne infection” by Luis A. Anchordoqui and Eugene M. Chudnovsky. They used SimScale to model airflow in an office and included a couple of nice visualizations:
The paper is quite concise and worth your time, just under 2.5 pages. Short version? Six feet ain’t enough and your office is a Petri dish.
From the physics point of view, we cannot find a good justification for a stationary 6-feet separation in a situation when people spend long time together in a room. Droplets containing the virus move in the air via convection. The convection pattern in a room can be very complex; see Fig. 1. It depends on the location of air conditioners, radiators, windows, and all items in the room, as well as on people producing vortices by moving around. The existing vortices in the air can make a location far away from the source of droplets more dangerous than the location 6 feet away. This applies to meeting rooms, office spaces, supermarkets, department stores, etc. The airflow pattern should be studied for all such facilities to avoid the spread of infection to large distances from a single infected person. The safest rooms must be those equipped with the air sucking ventilator at the top, like hospital surgery rooms
Luis A. Anchordoqui and Eugene M. Chudnovsky
https://arxiv.org/pdf/2003.13689.pdf?referringSource=articleShare
The antimalarials are much in the news due to Covid-19, so here’s an actual expert who knows them well and can explain. TL;DR – they’re unlikely to be much help as treatment.
The author is Derek Lowe, long a favorite of mine for his “Things I won’t work with” series and I recommend him highly.
ultracrepidarian 