David Knell
dave.cy
David Knell
@dave.cy
Geek, dad, pilot, sailor. Once hand-assembled a Space Invaders game for an Ohio Superboard II.
Cancelled my Netflix subscription before reciprocal tariffs kick in. I'll give Now TV a go instead.
May 6, 2025 at 8:05 AM
The ice maker at our restaurant (US-made, < 4 years old) failed. The spares required to fix are over $3000 - this part alone is $1400.

I just bought a complete new machine from a Chinese manufacturer, US stock, delivered with ice storage bin. For $1400.

Who's ripping off Americans here?
April 4, 2025 at 5:59 AM
She drives the cats mad; unfortunately for them, she's out of reach.
March 28, 2025 at 6:46 AM
Hmm. I don't see JD Vance popping up to condemn this actual silencing of free speech in Europe.
Hungary bans Pride events and plans to use facial recognition to target attenders
Amnesty International describes legislation as ‘full-frontal attack’ on country’s LGBTQ+ population
www.theguardian.com
March 19, 2025 at 4:58 AM
Naughty naughty..
March 18, 2025 at 11:12 AM
New Rose
YouTube video by The Damned - Topic
www.youtube.com
March 7, 2025 at 8:30 AM
Tom the Cat having discovered that there's a stream of warm air blowing out of the PC's power supply.
March 6, 2025 at 7:45 AM
This shows a prediction of where the SP500 would be, based on projecting a best fit of the 12 months up to 11/1/2024 forwards, against where it is now. The former is business as usual; the latter shows what Trump's cost the US stock markets so far - nearly 10%.
March 4, 2025 at 7:39 AM
There's some times when I'm proud to be British, and this is one of them.
February 26, 2025 at 7:00 AM
Uncloaking an AI chatbot..
February 19, 2025 at 7:50 PM
Test board with RP2350 in EasyEDA - gone off to JLCPCB to be made into a real thing. Fingers crossed that it behaves..

github.com/DaveKnell/RP...
GitHub - DaveKnell/RP2350-test: RP2350 test board - EasyEDA for JLCPCB.
RP2350 test board - EasyEDA for JLCPCB. Contribute to DaveKnell/RP2350-test development by creating an account on GitHub.
github.com
February 19, 2025 at 1:00 PM
Running a side-by-side comparison of three CO2 sensors - one from AOSong ($10), one from Infineon ($20) and one from Senseair ($40.) Initial results appear to show that one gets what one pays for: co2.dave.cy - but it may be that a bit of filtering will bring the results closer together.
co2.dave.cy
February 13, 2025 at 7:07 PM
Have to say I'm pretty proud of this - 37 views and 12 heart thingies. That's roughly one in three. Elon Musk gets about 1%, so I'm about 33 times more popular than an unelected South African wannabe despot who's dismantling core American institutions on a whim.
February 9, 2025 at 7:31 PM
Asteroid Destroyer (that's the cat's name) eyeing up the cheese.
February 6, 2025 at 11:46 AM
For those wondering about the complexity of the mDNS documentation in the ESP32 online stuff, all you need to set it going with a webserver is:

// Initialize mDNS
ESP_ERROR_CHECK(mdns_init());
ESP_ERROR_CHECK(mdns_hostname_set(<whatever>));
ESP_ERROR_CHECK(mdns_instance_name_set(<whatever++>));
January 27, 2025 at 7:22 AM
It's the cat, sleeping on the sofa.
January 24, 2025 at 1:49 PM
As part of a captive portal thing using an ESP32, I implemented a very simple DNS server which just responds to all incoming queries with its own IP. Taking out error handling and whitespace, it's 20 lines of C. I'm quite proud of myself.
January 23, 2025 at 12:19 PM
"Any problem can be solved by the addition of another layer of indirection" - it's this thinking that's led to the supplier's SDK taking 40 microseconds (at 160MHz, so > 6K instructions) to set up an SPI transfer (which, in my case, takes under a microsecond to complete) on an ESP32.
January 19, 2025 at 7:11 AM
So Buckethead had a couple of his guitars stolen. A fan helped him get one back, and he recorded this, dedicated to said fan: www.youtube.com/watch?v=Sw5s...
[Full Album] Buckethead Pikes #323 - Thank You Taylor
YouTube video by Buckethead Archive
www.youtube.com
January 10, 2025 at 10:12 PM
Violent video games continue to be the root of society's ills..
December 11, 2024 at 12:40 AM
Anyone interested in seeing various aspects of the air quality outside my house - it's here: co2.dave.cy I suspect the CO2 sensor needs to calibrate itself.

Interesting spikes in PMs and corresponding peaks in TVOC - possibly people lighting fires? Certainly could smell pine smoke yesterday.
co2.dave.cy
December 2, 2024 at 7:48 AM
Reposted by David Knell
I posted the last version of this too hastily. I wasn't satisfied with the art so I added more yeast. Now I think I'm done with it.
November 26, 2024 at 7:21 PM
Fired up the ESP32-based air quality meter - measures PM at various sizes, TVOC, pressure, humidity, temperature (about three times as its bundled with other sensors), altitude and CO2 spread over four I2C buses. Everything has worked without a single bodge wire. Thinking I maybe still have it...
November 30, 2024 at 10:31 PM
Sunrise over Limassol with the waning moon in the sky.
November 29, 2024 at 6:19 AM
There's something of the Dominic Cummings in Elon's new DOGE recruitment ad:
November 15, 2024 at 1:19 PM