Electrical Engineering

Even if you answer your own question immediately, this sets a bad example for people to assume we are the free alternative to Freelancer.com. I am, unfortunately, going to agree with the going close vote, to protect future me from many more questions that genuinely intend to have us as Google-Code-Monkeys. I hope you can rewrite/regroup your question-answer pair to fit the rules of asking better. — Asmyldof 10 mins ago

PlasmaHH

@Asmyldof the xkcd nerd/geek chart?

Asmyldof

9:25 AM

@PlasmaHH No, a test.

Never mind

I am hungry

I need a servant

PlasmaHH

<-- brunch at alex (a café)

Asmyldof

only if its short for alexandra and shes cute

Else Im just going to make a snack

:-P

Asmyldof

9:47 AM

Barbecue Chicken!

👏👏👏👏

trilolil

10:07 AM

Hello @Asmyldof

:)

@Asmyldof could you confirm whether this is a valid second order band pass filter: imgur.com/Rp5EMYF

?

PlasmaHH

We are only affiliated with the first order here

trilolil

c'mon maaan

@PlasmaHH I'd expect 40dB/decade

not what I am seeing right now...

or am I misinterpreting it?

trilolil

10:45 AM

@Asmyldof @PlasmaHH any idea?

Glavić

11:22 AM

Hello to all.
I have a simple question. Since we have a http://codereview.stackexchange.com/ where you can review you code. Is there any similar stackexchange for "circuits review"? I would like a comments on my custom circuit, if it can be upgraded/fixed etc?

PlasmaHH

@Glavić if you have specific questions about an existing circuit, this can be on topic here. Generic "anything to say?" Questions tend to be closed as too broad though

Glavić

@PlasmaHH So best solution would be to ask here?

PlasmaHH

11:55 AM

@Glavić look at some existing question sthat were well received and check if yours would be of similar quakity

Glavić

@PlasmaHH Will do that before asking here, ofc :D Tnx

PlasmaHH

12:21 PM

Hm, I never looked in detail into hi-fi stuff, but it seems that there is an 8 ohm speaker camp and a 4 ohm one

Asmyldof

1:56 PM

@PlasmaHH Go to the 8 ohm camp and find your tent?

Asmyldof

2:39 PM

Vehicle Based IMU -- I would think there would be many better ways to make an IMU than to use an entire vehicle

Branden Boucher

3:21 PM

I have a proposal that the follow up to "May the 4th" (Starwars references), which is Revenge of the 5th, actually be held on May 6, as May 5th is Cinco De Mayo. And many people will be feeling the "revenge" of the 5th tomorrow morning.

Asmyldof

Except that it is liberation day

Or nothing special

Or Some weird ass russian day

Nick Alexeev

3:51 PM

@Asmyldof Weird ass Russian days are May 1 (labor day) and 9 (victory day). In practice, it means nation-wide shutdown for a week (or two weeks, if we account for hangover).

Asmyldof

@NickAlexeev Which means broadly speaking today is also a weird ass Russian day

:-P

jippie

I have two trees in my garden which refuse to go down. I think I call them Asterix and Obelix from now on.

Asmyldof

!?!?! Reboot and many keyboard configs further and I still have no quotes or backticks ever

jippie

sounds like a i18n issue

Asmyldof

@jippie Yes. But where!?

jippie

3:57 PM

system language / keyboard layout

Windows or an OS for grown ups?

Asmyldof

The issue is in Windows

But I have never had this problem

This is me pressing the quote key 10 times:

jippie

hmmm ... Is there a keyboard language icon in the system area?

and/or did you try a different keyboard? although that would be odd, failing quote key.

Does ~ and ^ work as expected?

I had this colleague at work who has been inserting quotes in his code (he is a programmer by profession) by using copy and paste for over 6 weeks... He never notified the helpdesk about the issue ...

Asmyldof

4:35 PM

@jippie no

39 mins ago, by Asmyldof

!?!?! Reboot and many keyboard configs further and I still have no quotes or backticks ever

The Photon

@Asmyldof Call a priest.

Your computer is possessed.

Asmyldof

Not an option

Just switched to Standard US Stupid Keyboard in US English, rebooted and still nothing

10x 6 key:
666666666
10x 6key with shift:

jippie

@Asmyldof as in hardware I meant

Asmyldof

@jippie 3 different keyboards

And also, on account of 6 working but carret not, not a HW issue

When I figure this out, I may need to open a SU.SE account just to document the poop that's happening

jippie

Is there still such a thing as safe mode? Although I wouldn't know how that would help other than testing the keyboard.

Asmyldof

4:46 PM

It is very likely safe mode will work

Since this obviously is some setting

and it loads none of those on safe mode

jippie

/me shrugs. Maybe set the keyboard config during safe mode.

I left Windows couple years after Win98.

The Photon

@jippie, Is it correct that udev is where I should be looking to figure out what happens when a network cable is plugged in or unplugged?

(on beaglebone with Debian)

PlasmaHH

5:27 PM

@Asmyldof have 4ohm speakers....

Asmyldof

@PlasmaHH can it not be set to drive them anyway?

Or put two in series, usually channels are single or double in high power RMS systems

So you would likely not need 7 loads

If it is a PSU issue, you can load that down with anything that will load it down at any point and do your measurements

PlasmaHH

Ah, no, two totally different things... The amp that will come in for the weekend to repair will be run with the dummy loads, I have found enough... While researching a bit about that amp and looking at my stuff I just found that there seems to be those camps... For the stereo I drive the 4ohm ones with a 6-8ohm designed amp, no problem. The surround one expects main to be 4 and the others to be 8....

I am planning to get a new 7.2 or 5.1 one and checked what speakers I have around and noticed these things... I guess that when the ampmexpects 8 for all, it's not wise to mix

Hm, might just put some resistor in series ^^

Asmyldof

All depends on your expectations

PlasmaHH

I expect perfect sound of course ;)

Asmyldof

5:46 PM

@PlasmaHH No such thing in the history of humanity

Except for my voice, of course

PlasmaHH

The sound a pigeon makes when a bus runs it over? (Which BTW. Is pretty indistinguishable from it running over a tetra Pak)

jippie

@ThePhoton no udev is more when plugging the NIC, not the cable

The Photon

@jippie O

So the last time I knew about this stuff, there was still hotplug daemon.

What takes its place nowadays?

jippie

udev :-p

hang on there is a smart monitor thingy.

The Photon

OK

jippie

5:55 PM

You want to check the man page for

udevadm monitor

The Photon

@jippie I have been using that. I think it is just a way to see what messages are being generated to/from? udev

jippie

I have a flag --environment after it to find a serial number of a usb device, but I'm unsure top of mind what environment is limited to

right

so if you plug a cable into the nic, nothing should be shown

The Photon

And I don't see anything generated when cables are plugged/unplugged

@jippie Yes, that's what I see

So what generates an event for wicd or connman to do its thing?

jippie

unplugging the NIC on a BBB is somewhat of a challenge I guess, but you can plug in a USB device just to be sure the command works as expected

The Photon

@jippie good point, I'll do that.

jippie

5:59 PM

I'm not familiar with wicd and connman. As a matter of fact I've never ran into if-up and if-down events other than from scripts ...

Why not just purge conman/wicd and configure a static IP the old way?

The Photon

@jippie Because I also want to be able to use DHCP (with minimal changes to config files)

If I purge wicd, and configure for DHCP, then unplugging and replugging doesn't bring the network back up

jippie

I have a package ifupdown on my ubuntu box, but it may collide with the other two you mentioned

The Photon

@jippie let me see what BBBian has...

jippie

dpkg -l | grep ifup

or grep connman

or grep wic

etc

Asmyldof

....

jippie

6:04 PM

nature calls. back in a moment

Asmyldof

Ooooh! I should pack up PlasmaFace's package so I can send it out tomorrow

Oh jah, fixed my quotes!

YAY ME!

Location: Netherlands + Default System Language: EN_GB + Keyboard: NL (US_Intl) borked it, now with all US (US) it works

but no intl support

The Photon

@jippie ifupdown is also on BBB/Debian

Asmyldof

So... now I'm going to carefully switch things so that I get Intl back, and if that means I cannot set my sys language to ENGB... eh

The Photon

And it does sort of conflict...
If I set /etc/network/interfaces for dhcp and wicd for static, then plug in a cable, I'll see the DCHP messages exchanged, but the interface gets configured according to the wicd static configuration.

@Asmyldof What are you gonna do when you want to give a price in euros?

Asmyldof

If I cannot move back to Intl keyboard:
1. Shout at my laptop
2. Call Microsoft NL and berate every single employee
3. (optional): When happening onto them, punch at least three of said employees hard enough in the face to break nose or jaw
4. Start working for the government, since they work with 80's software and all type EURO in place of the symbol anyway.

Time is fixed, and ""^~ YES!

Next up, change intl keyboard

And broken....

#$%@%@$%!&%@$#%!$#!&* (notice how there are no carrets or tildes there!)

jippie

6:20 PM

@ThePhoton apt-get purge wicd

carefully check if it doesn't purge ifupdown too

I have my static IP set in /etc/network/interfaces on my ubuntu box.

€ cat interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
        address 192.168.0.130
        netmask 255.255.255.0
        network 192.168.0.0
        broadcast 192.168.0.255
        gateway 192.168.0.1
        # dns-* options are implemented by the resolvconf package, if installed

Asmyldof

hmmm... yesterday this one installed itself:

support.microsoft.com/en-us/kb/2970228

I feel there may be a link there....

The Photon

6:40 PM

@jippie Yes, That works to make static IP work. But then I can't get DHCP to work without re-installing wicd.

jippie

You can change that config file for dhcp

The Photon

@jippie You mean /etc/networ/interfaces?

Asmyldof

@jippie You have that euro sign in there just to mock me!

The Photon

Yes, even if I change that to be set for dhcp, I haven't gotten it to reconnect after plugging in hot without having wicd installed.

jippie

stop/start the daemon and you're done.

this is how my BBB is set up

The Photon

6:42 PM

@jippie which daemon?

jippie

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet dhcp
# Example to keep MAC address between reboots
#hwaddress ether DE:AD:BE:EF:CA:FE

# The secondary network interface
#auto eth1
#iface eth1 inet dhcp

# WiFi Example
#auto wlan0
#iface wlan0 inet dhcp
# wpa-ssid "essid"
# wpa-psk "password"

networking ifupdown

The Photon

@jippie Anyway, even after rebooting, dhcp doesn't recognize plugging in hot.

Unless wicd is installed

jippie

need to go out

ttyl

The Photon

@jippie thanks for your help

J.Doe

7:24 PM

Hello everybody

short question

a high pass filter (and low pass filter) has a resonant pulsation which is almost equal to the natural pulsation

is this appoximal equality also the case with a band pass filter?

or are these perfectly equal when dealing with bpf?

this is what I am speaking about: imgur.com/oi5jeA8

in case of a hpf

any idea? @ThePhoton @TheNoonMoose :/

TheNoonMoose

i am familiar with filters but not the terms resonant or natural pulsation

J.Doe

I think a synonym is: natural frequency

or resonant frequency

TheNoonMoose

sorry, i'm not your guy for this. ¯_(ツ)_/¯

J.Doe

ok np tvm

The Photon

8:14 PM

Sorry, I don't deal with filters in that much detail.
I think those ways of characterizing a filter are a holdover from the days before simulation was cheap and quick. Nowadays, just simulate your filter and see what the response is.
Of course if you're designing filters every day you're going to want to know a few tricks that let you get the filter right with a minimum number of design iterations.

Asmyldof

10:16 PM

:/

Can't seem to find any disks with TB's of magnetic storage and 100G+ flash for separate access.... did I dream those existing a year ago?

The Photon

@jippie I think I got it.
The answer was uninstall wicd and install ifplugd instead.
Now network hotplug events get detected in both DHCP and static IP modes, and all configuration is done in /etc/network/interfaces.

Asmyldof

Just don't accidentally install an update for the Russian Ruble, or you'll never get it back to working!

The Photon

11:26 PM

@Asmyldof I will keep that in mind.

Transcript for

Electrical Engineering