fest

19 ms·

1.
by fest 1y ago
Thanks, seems to fit the theme!
2.
by fest 1y ago
Related to the Moore's work, I also enjoyed Engineering reminescences[0] as a historical account how people figured out ways to make accurate things in metal, more than a hundred years ago. 0: https://www.gutenberg.org/
3.
by fest 1y ago
When I was doing stepper control on rp2040 I looked into using PIO but the 5 bit counters and 32 instruction limit made it too awkward to use. What worked better for my needs was dedicating 2nd core for just motion control and bit-banging t
4.
by fest 2y ago
On this topic I've been wondering why are the air-air heatpumps significantly cheaper than air-water units? As far as I could tell, there's not that much of a difference (different heat-exchanger, circulation pump instead of a fan
5.
by fest 2y ago
I found it interesting that CNC machines aimed at precious metal processing have an optional access control system for swarf/dust collection bins- presumably so that the technicians operating the machine don't steal the "wast
6.
by fest 2y ago
Metallurgical microscopes illuminate the sample "from the top side". The actual implementation even goes as far as making sure the illumination happens on the optical axis of the objective (as if the light was emitted from your ey
7.
by fest 2y ago
> Might as well use PIO to implement I2C or UART :) PIO actually came in handy for me when interfacing with an x-ray sensor which had 12 or 14 bits long UART data frame- not many micros have such a flexibility in their UART peripherals.
8.
by fest 3y ago
I built a couple of glasgow devices and used one extensively- it becomes very useful once the IC in question has an interface you can't practically use with a microcontroller. I used it to capture data from a thermal imaging sensor (
9.
by fest 3y ago
Yes, but I always found it strange (though I lack any exposure to "enterprise" networking equipment).
10.
by fest 3y ago
Can you weigh in on the decision to require UniFi controller instead of providing on device configuration interface as well?
11.
by fest 3y ago
I can't really go into details, but FrontRow wasn't the most bizarre thing Ubiquiti was working on, just the one that got reasonably close before being shelved. IIRC Access reader isn't the only product the FrontRow R&D c
12.
by fest 3y ago
This is actually a common problem for test fixtures that involve miniature coaxial connectors (pretty much all of them are rated for few tens of mating cycles): even if the connector on device is used for assembly/repairs and goes thro
13.
by fest 3y ago
Why are these reasons wrong? I have a similar attitude in my field (UAVs), where many desperately chase the next whizzbang technology, ignoring the boring, old fashioned stuff (workflows, UX, 3rd party addons).
14.
by fest 3y ago
It would, if I had them in the first place (most of the systems I've seen locally don't- it's typically just a motor and keyfob here).
15.
by fest 3y ago
I use a very crude DIY setup for garage doors and yard gate: bought a spare keyfob on aliexpress, took it apart and connected it to wall power supply and ESP relay board running esphome. Works great and will work as long as my garage door a
16.
by fest 3y ago
You can also convert the DICOM images to 3D model and print it. I did it with MRI scan of my head (isolated the brain specifically) and kept it on my desk at work, ready to be handed to whoever came by wanting to pick my brain.
17.
by fest 3y ago
Yes, unfused 10A range would have been my guess, but if device under test doesn't have short-circuit protection, it might as well die during the few tens of milliseconds that the fuse needs to heat up and blow, as well as a user error
18.
by fest 3y ago
What exactly happened there, and why do you think it wouldn't happen with a more expensive meter?
19.
by fest 3y ago
They are widely used in narrow circles :) Two of (arguably the best) open source RC aircraft flight controllers (ArduPilot and PX4) are using extended Kalman filters in their state estimators (essentially sensor fusion that provides attitud
20.
by fest 3y ago
Hopefully the firmware development won't stall like it was with v4. Rp2040 is a decent choice for relatively slow speed digital bus multi-tool, but the USB1.1 speeds will be somewhat limiting (IIRC I achieved somewhere around 700-800KB
21.
by fest 3y ago
Having thought about this when I retrofitted a heat pump in my house, I don't see how a buffer helps here. For a buffer to work, it necessarily needs to be hotter than supply temperature, which means more losses and more work for the h
22.
by fest 3y ago
It's all relative. It has gotten at least an order of magnitude less expensive over the last 10-15 years- 3D printing, low cost PCB manufacturers, availability and cost of automated machine tools like CO2 laser-cutters. It has actually
23.
by fest 3y ago
Even if it was all metric, in embedded systems you often have to deal with the same measurements in different units, like angles in radians, degrees, centidegrees, length in mm, m, cm, due to various reasons (mostly historical, like integer
24.
by fest 3y ago
I recently converted a cheap consumer toaster oven and a hot-plate to PID controllers- I wouldn't expect their thermostats to work at all. In both of them, the adjustable bimetalic switch that controls temperature either at the surfac
25.
by fest 3y ago
My guess is that they need to be cut using EDM (slow) and need expensive CMM machines to make sure the resulting die shapes match the tolerance. I know you're probably referring to OEM hand crimping tools that cost on the order of 500€
26.
by fest 3y ago
Google is really not helpful in finding out what the nut-retapping trick is :> Do you mean cutting the screw to length with a nut on it, which then fixes the thread as you unfasten it?
27.
by fest 3y ago
Of course an experienced developer would have thought about edge cases, but I can see a thought process like: ok, I'm comparing two strings. "" != "123" in languages with built-in string types. I'm definitely n
28.
by fest 3y ago
Zephyr fits the description IMO.
29.
by fest 3y ago
Though, in this case, manpage doesn't exactly spell out that two strings of which one is 0 chars long results in a match. I often remember my PHP days in horror, but mysqli_query manpage does warn you about SQL-injections now.
30.
by fest 3y ago
> The only way to avoid this kind of scam is buying vehicles that have done the official maintenance/inspection. Agree, but not everyone here can afford <5 year old vehicle, so people have to do with the means they have. As soon

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