Some sporadic improvements to my 65(c)02 graphical emulator:
Still many things to do…
I’m reading about heat pumps (for some reason) and getting annoyed that their power level is listed in “BTU”, which is not only a non-SI unit, forcing me do to conversion, but the wrong non-SI unit! BTU is an energy unit. What they mean is “BTU/hour”.
It seems that it is so common that some websites that explain how heat pumps work just say “1 kW = 3 415 BTU” instead of indicating that a “BTU” power level should be read as BTU/h and that 1 kW is 3 415 BTU/h…
On the back of the board, there is a single square flat capacitor (0.68 µF, 250 V~). No other components.
My pedestal fan stopped working completely (doesn’t turn on anymore), so I opened it up.
It looks like the control board connects mains power to one of three wires (labelled HI, MED, LOW) that go to the fan motor to set its speed; I did it manually and that made the fan work.
But there is something I don’t really understand: Where is the DC power supply to power the low-voltage components? It must be on this board since it only receives mains AC, but I don’t see anything that looks like it…
the wise man solemnly bowed his head and spoke: “There’s actually zero difference between good and bad code”
TIL that bash’s echo built-in actually checks if its write() to stdout actually wrote the full string or not, and if not will dutifully try to write the rest of the data again. It also ignores SIGINT and SIGTERM while doing this. This is fine, but if you happen to have a bug in your kernel driver that makes a write to a sysfs file return less than what was passed in, echo blah > /sys/… will hang and you’ll be confused. /bin/echo also retries the write indefinitely but can at least be Ctrl-C’d.