Electrical Engineering

Starting to look like the first impact of Microchip's purchase of Atmel is found. All secondary SW development projects have made no more progress since the purchase. The ones on Git also no commits since then.

Extrarius

Does it mean we can get free atmel samples? Microchip is very generous with free samples

Asmyldof

I wouldn't know

Asmyldof

5:51 PM

@PlasmaHH Last chance to change your mind. Going to tape everything up and weigh it when I'm home.

@jippie Hopefully I'll manage to take your pictures as well tonight or tomorrow

The Photon

6:12 PM

@Asmyldof Put all your flour & other grains in the freezer. (You might have to first buy an American style chest freezer)

Asmyldof

6:38 PM

@ThePhoton Nope. 75% is going away. Freezing may not even help once it's past the egg stage

The Photon

7:25 PM

@Asmyldof Yeah, but the new flour you buy that you don't want to get re-infested.

Asmyldof

I'm just going to force other people to do my baking

Preferably ones who look cute in aprons

PlasmaHH

8:37 PM

@ThePhoton what makes a chest freezer "american style" ?

The Photon

@PlasmaHH Big enough to hold a couple of bodies.

PlasmaHH

@ThePhoton american bodies? so 1800 liters volume? ;)

The Photon

@PlasmaHH 1.5 American bodies.

(ANSI Standard)

PlasmaHH

we size them in liters in ISO standards ^^

The Photon

@PlasmaHH We prefer traditional units, like hogsheads.

PlasmaHH

8:40 PM

yeah, so you can spare you the encryption since nobody understands a bit

The Photon

@PlasmaHH We outlaw encryption .... for exactly that reason.

PlasmaHH

and thus I had been set on a certain nofly list

PlasmaHH

8:59 PM

ok, I am probably missing something here as I am too tired...

boost converter, VCC -> Ind ->(violet) FET -> (blue) R(150mOhm) -> GND and yellow is the FETs gate...

on a breadboard so maybe thats the issue but I don't really get why exactly there are the additional spikes...

aaaaand the scope locked up... for the first time actually...

DanielSank

9:57 PM

Anyone know how to combine wires with arbitrary names into a bus in Altium?

The Photon

@DanielSank If you're using version 16 or newer, look into the new "harness" features.

DanielSank

@ThePhoton I was just looking at that.

The Photon

@DanielSank The names of the signals within the harness doesn't have to match the names of the signals being connected to the harness, as far as I know.

PlasmaHH

I feel ignored, or are you only answering questions where you know the answer? ^^

Asmyldof

@PlasmaHH Impossible to give an answer. What with your general active feedback to others, you might add pictures and/or schematics

PlasmaHH

10:04 PM

@Asmyldof darn, I was hoping I am missing something obvious

Asmyldof

Who knows

Might be oscillations

Might be leprechauns

PlasmaHH

hm, I think I could just recreate it in a simulation, yay

The Photon

Why does numpy.polyfit return coefficients highest-order first, but np.polynomial.Polynomial expects lowest-order first?

Asmyldof

10:19 PM

So many more strangenessessesess in numpy and several others

PlasmaHH

indeed some current that flows through the fet is causing the voltage

Giskard42

@Asmyldof Did you just have a banana problem?

PlasmaHH

it seems that due to the voltage going negative current flows through the body diode or so... can you check in ltspice if its flowing that way?

Giskard42

@PlasmaHH Check if current is going backwards you mean?

PlasmaHH

that I can see already, but what path it takes, through the body diode or source-drain

Giskard42

10:29 PM

@PlasmaHH Oh, okay now I understand

Isn't there a mosfet in ltspice without the body diode?

I thought there was a test package or something

Then you could use that and an external diode

PlasmaHH

hm, dont know, never seen it, might work

puttig a diode in parallel with it makes some current go through it, but not all and/or the same waveform, but its definetly something

so it seems to be oscillating between parasitic capacitances and inductances through that body diode :/

chosing other fets makes the oscillation even higher frequency, so the question is what parameter do I have to look at

DanielSank

@ThePhoton Ok I guess that's where harnesses are more general than busses.

@ThePhoton np.polyfit works with np.polyval.

I've never heard of np.polynomial.Polynomial before!

The Photon

10:54 PM

@DanielSank O sweet baby jeezus

DanielSank

@ThePhoton wut?

It makes sense.

The Photon

How many different incompatible ways do they need to do the same thing?

DanielSank

Two.

p = np.polyfit(x_data, y_data, degree)
y_fit = np.polyval(p, x_data)

It's that simple.

Yes, polyval and polyfit put the coefficients in what seems like the wrong order to most people, and yes that order is incompatible with np.polynomial.Polynomial.

The Photon

Now I'm doing

`p = np.polynomial.Polynomial(np.polyfit(x, y, degree)[::-1])
y = p(x)`

Because my numpy is too old to have flip()

@DanielSank Has Guido been told there's two ways to do something?

DanielSank

@ThePhoton Hahahaha, no :-)

DanielSank

11:34 PM

Is there really no way to take a subset of the wires in a bus and stuff them into a new bus with a different name?

This should not be hard.

Giskard42

@DanielSank An actual, physical bus?

DanielSank

@Giskard42 Apologies: I'm talking about Altium's schematic designer.

Giskard42

I think you'll have a lot of wiring and some angry passengers if you do this with a real bus.

DanielSank

heheheh

Giskard42

(sorry).

DanielSank

11:36 PM

In the end, I'm trying to do this.

Giskard42

'fraid I don't know altium, sorry.

I hear altium has some unwanted side effects like PTSD so I try to stay away from it.

DanielSank

It's mostly fine, but I'm finding multi-channel design confusing.

The Photon

@DanielSank Yeah, busses is not Altium's best thought-out feature.

DanielSank

@ThePhoton There has got to be a way to do what I'm trying to do.

The Photon

@DanielSank You might have to manually place two instances of the sub-circuit instead of using Repeat()

DanielSank

11:38 PM

@ThePhoton Yeah but what do you do when you have a hundred channels?

How could a program this old not support this?

The Photon

@DanielSank Hire another guy to do layout.

DanielSank

-_-

That's absurd.

The Photon

@DanielSank Remember Altium started out as a budget tool. It only turned into a monster by organic growth.

Giskard42

@DanielSank Try doing all your cad layout in Assembly. It's very flexible.

The Photon

For 100 channels think carefully about how to name your input ports to avoid the problem.

DanielSank

11:42 PM

@Giskard42 Recommending a new tool is nice in principle but I work in a group with other people. No dice.

Giskard42

@DanielSank Just trying to be funny :>

DanielSank

@Giskard42 Oh you meant like x86 assembly. Ha.

Giskard42

Sorry, it's the end of the day and my emotion chip has latched up into humor mode

Nick Alexeev

Why does Altium BoM exporter lump different component values into one line item? Like this:

The Photon

@NickAlexeev Because you grouped by footprint, not by value or comment.

Why it only gives you the choices "quantity", "footprint" and "comment" for grouping, I'm not sure. There must be a way to group by other columns.

Nick Alexeev

11:53 PM

@ThePhoton I see. I'll go hit the documentation.

@ThePhoton The list of fields to group by is adjustable, apparently. Fields can be dragged to and from the list in the upper-left corner.

DanielSank

@NickAlexeev Any idea how to do this?

Transcript for

Electrical Engineering