markrages

The complaints in the linked thread are not about reliability, performance or homologation.

More thoughts:

- The indicator is ratiometric and the exact supply voltage doesn't matter. If it works acceptably well down at the +5 V USB bus voltage, the circuit would get a lot simpler.

- I suspect that driving the circuit with a variable voltage is sufficient, and the potentiometer is unnecessarily. Then a DAC or PWM with a plain old opamp would do the job.

Anyone following this as a guide: The calculations about potentiometer current are incomplete, although the selected part appears to be fine for this application.

The current in all three potentiometer terminals is limited to 25 mA. The terminal with the maximum current is not the wiper, but the end terminal which carries both the wiper current and the end-to-end current. So the part needs to handle 15 mA, not 10 mA.

It is also good to calculate the power dissipated by the potentiometer. By inspection, the Thévenin equivalent circuit of the indicator is a 12 v supply in series with (1800/2+300) = 1200 ohms. The maximum power transfer with occur when the potentiometer is also presenting 1200 ohms. This is not at either end of travel!

Going through the algebra it looks like 1200 ohms (greatest dissipation) happens at 40% of the potentiometer's travel. It's still only 124 mW, so this part is well within its 1 W absmax.

Much steam heat is sized for open windows.

https://www.bloomberg.com/news/articles/2020-08-05/the-curio...

Sometimes I get the feeling that many developers are functionally illiterate. (In the https://quoteinvestigator.com/2012/12/11/cannot-read/ sense.)

I can spend as much time as I like writing comments or design documentation or whitepapers or commit messages, but nobody reads it. Maybe they will set up a meeting for me to read it to them.

I've noticed that for years in embedded (where we use "Intel HEX" formatted files) but I ascribed it to a field full of eccentric loners doing idiosyncratic things, or some kind of DOS 8.3 brain damage.

Those are advanced topics and you can look them up if you need them.

Generally, Python does the right thing by default for scripting use: line buffered, system encoding, EOF handled naturally by the iterator protocol.

It's in the name - a copy of Matlab's procedural API. So matplotlib is popular because they copied Matlab's original mistake.

(The procedural / global state API is actually reasonable for interactive plotting from a REPL.)

Threads and naming things, two famously easy problems.

Cycle counting is dead for ARM chips with their wait states and instruction pipelines and lazy stacking. Works great for PICs though.

The "standard" motor control setup for FOC is to do the ADC measurement synchronously with the PWM, to sample the current while the low-side switch is closed. Then the flux angles and voltages are computed immediately afterwards, and the PWM duty updated for the next cycle. This all happens in the interrupt, in a very hard real-time system -- start missing interrupts and all hell breaks loose.

PWM is run as fast as you can get away with, 20 kHz minimum (human hearing). The controller spends maybe 80% of itw time in interrupt context, leaving main context for tasks that are not time-sensitive.

"Verbing weirds language."

I wrote a tool to do this for circuit board artwork changes. It used gerbv to rasterize the vector (gerber) files, then used XOR on the pixels to make unchanged areas disappear. For such a simple tool it is quite useful.

A good excuse to be cranky in the morning is worth the price of addiction.

Or shooting a man in Reno, just to watch him die.

In my system it is called "librecad". I guess qcad is non-free somehow.

> This might be useful for directors+ but is really a waste of the time of 50-100 other people. This is a problem with status meetings too;

A status meeting serves to reinforce the social status of the one who called the meeting. No other status is relevant.

That was the era of the elecroluminescent backlight.

This technology required a high-voltage (~100V) squarewave across the mostly-capacitive EL panel. This squarewave was at audio frequencies.

The panel also happened to function as a piezo tweeter, depending on mounting.

I worked for a cell phone company at the time. I have two memories of this technology:

1. Using the prototype phone out of its case and touching the 100 V squarewave to my ear. That's some tender skin...

2. Using a primary transformer in reverse as an audio transformer, to play the lab stereo over EL panel. It turns out the panel color changes a little bit with frequency.

After about the fourteenth time I accidentally blew my timing and size budgets with double-precision softfloat routines, I learned of -Werror=double-promotion.

I just submitted "The many myths of Paleo sleeping" https://news.ycombinator.com/item?id=29902569 (0 comments), on its way to total obscurity.

That's alignment, not indentation. Alignment should always be done by spaces.

A decent editor supports smart tabs

Finally!

> It is now official. Netcraft has confirmed: BSD is dying One more crippling bombshell hit the already beleaguered BSD community when IDC confirmed that *BSD market share has dropped yet again, now down to less than a fraction of 1 percent of all servers

cdrecord first induced me to try Linux in 1997. I had spent $400 on the Sony 2x CD burner with the caddy but Windows wasn't stable enough to reliably burn a disc. cdrecord was free and worth changing operating systems for.

Just wait until you get a sheared pin on the distributor drive... Compression, fuel, spark, no go.

It is a special case of Morningstar's law, you can't tell people anything. http://habitatchronicles.com/2004/04/you-cant-tell-people-an...

> Why does the linter rule not, instead, check if the while loop is unbounded and warn the user of that?

Indeed, the linter only needs to incorporate of the many known solutions to the halting problem.

I learned Python around that time, when the docs said that `open()` is deprecated and to use `file()` as a constructor instead. Still unlearning that habit.