Electrical Engineering V2 - Developers

[QUOTE=nikomo;46892998]pix I like 'em. Got the Due today, had some fun with the mouse emulation thing. Sainsmart boards are good. They look a bit funky in places, but I like how you can clearly see the traces through the black silkscreen, sometimes you can't see traces through black. You can't see the traces on the image though, I don't have a good enough camera to capture them.[/QUOTE] First opinions on the Due?

[QUOTE=Leestons;46893089]First opinions on the Due?[/QUOTE] It's a bit expensive, but it's fucking brilliant to have a 3.3V board with tons of performance and Flash space, with 4 UARTs, CANbus protocol, and 2 DACs. I haven't played around with the DACs yet, but I had a look at it fast and they have 12-bit resolution, that's pretty good. The ADCs are also 12-bit, but they're by default 8-bit, in order to stay compatible with normal Arduino code, you can set them to 12-bit accuracy with one function. And the USB stuff is pretty fun, but you can get an Arduino Micro from eBay for a bit over 5€ if you want to play around with that. Also, microUSB connection is so good, the miniUSB etc. connectors on the other boards are a bit annoying, can't just carry around one cable that you also use with your phone. Having to use the beta version of the IDE is a bit annoying because Debian doesn't straight-up package it, and I run Debian on my laptop, but that's not that big of a deal.

So I got this piece of crap battery that's likely an explosion hazard with a third of the advertised capacity: [URL]http://www.ebay.ca/itm/130693998479?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649[/URL] What would be a good replacement 12v lithium ion battery that I could buy with a proper charger? Maybe some sort of power tool battery? I'm just going to be powering my 20 watt Lepai amp.

I like these OLEDs a lot. [video=youtube;v39sbBCtPtY]http://www.youtube.com/watch?v=v39sbBCtPtY[/video] [editline]9th January 2015[/editline] Nevermind those pixels on the right side that won't turn off. [editline]9th January 2015[/editline] Or the fact that my uptime counter only believes in seconds.

[QUOTE=papkee;46895434]I like these OLEDs a lot. [B]Nevermind those pixels on the right side that won't turn off. [/B] Or the fact that my uptime counter only believes in seconds.[/QUOTE] is that a bug in the screen or your code? The screen looks very neat (and so does your program!) but if it has such a big flaw I might not get one. [editline]10th January 2015[/editline] funnily enough, I saw the following video just before people on here got to mess with their tiny OLED's. Perhaps it's a fun project for you to do as well [video=youtube;qOs_LC-ObDo]http://www.youtube.com/watch?v=qOs_LC-ObDo[/video]

Sooo.... [t]http://i.imgur.com/bsLoMhl.png[/t] I have to ask, why would someone order from Sparkfun, on items like these? Who's in such a hurry they can't wait 2 weeks shipping, when they save $35+? Not that Sparkfun is even an option for me, due to shipping costs.

[QUOTE=nikomo;46897502]Sooo.... [t]http://i.imgur.com/bsLoMhl.png[/t] I have to ask, why would someone order from Sparkfun, on items like these? Who's in such a hurry they can't wait 2 weeks shipping, when they save $35+? Not that Sparkfun is even an option for me, due to shipping costs.[/QUOTE] It's been like that forever.

[QUOTE=scratch (nl);46896408]is that a bug in the screen or your code? The screen looks very neat (and so does your program!) but if it has such a big flaw I might not get one. [/QUOTE] I think it has to do with either the I2C connection or the u8glib, because after a few power cycles of the display they pretty much disappear.

I2C? yeah that probably explains things. I had very fun stuff happen with it on a 20x4 screen as well [t]https://dl.dropboxusercontent.com/u/43645231/photos/electro/2013-11-05 22.49.35.jpg[/t] probably the most silly bug I had once was when having a scrollable menu. You'd rotate a potentiometer and a little arrow would go up and down all the way to the right, but if you rotated too fast it would randomly jump one character to the left. It would still go up and down while going trough the text that was orignally there, but the screen would freak the fuck out when you selected an option :v: the only way to fix it seemed to be resetting the arduino.

Managed to fix that TV that the roaches shat to death. Hooray, it's working! Prepare to mount panel back into front bezel. Managed to do so. Flip it upright, power it on. ...I cracked the fucking screen. [img]http://i.imgur.com/VZWtorQ.jpg[/img] God fucking dammit. Looked up prices for a new screen, the ONLY site that even lists a price wants at least $1K, not worth it for a TV you can buy for $600-700 refurbished. All the other sites want you to buy a carton of 10. All I can do now is part it out and hope to recoup my losses.

Did you crack it all the way through ?

[QUOTE=Chryseus;46901312]Did you crack it all the way through ?[/QUOTE] There was a chip on the top that cracks about 2-3" inside of the viewable area, but it's broken enough that there are brightly colored spots and lines streaming down from where the crack is present.

[img]http://i.imgur.com/X7E05UC.png[/img] My god that PCB is so ugly This is my first time I've been playing with KiCAD to make basic 555 LED blinker circuit. Now how do I make my PCB look proper instead of spamming it with vias?

Does anyone still make WWVB receiver modules?

[QUOTE=POLOPOZOZO;46904422]Does anyone still make WWVB receiver modules?[/QUOTE] Looks like all the publicly available modules are discontinued ([URL="https://www.sparkfun.com/products/retired/10060"]C-Max's Receiver[/URL]), [URL="http://www.digikey.com/product-search/en?x=9&y=10&lang=en&site=us&keywords=561-1014-ND"]Digikey[/URL] has discontinued it as well. However you may be able to pull one from just about any [URL="http://www.leapsecond.com/pages/sony-wwvb/"]radio-time alarm clock[/URL]. [URL="http://www.joejaworski.com/wwvb/"]Here's[/URL] some more decoding processes for both the Phase modulation signal and the PCM signal. If you're lucky, you may be able to see if [URL="http://www.c-max-time.com/products/showProduct.php?id=2"]C-Max[/URL] has a few leftover in stock.

[QUOTE=Abaddon-ext4;46904085][img]http://i.imgur.com/X7E05UC.png[/img] My god that PCB is so ugly This is my first time I've been playing with KiCAD to make basic 555 LED blinker circuit. Now how do I make my PCB look proper instead of spamming it with vias?[/QUOTE] Try moving components, rotating them and placing them in better positions, C1 could be turned around 90 degrees for example. Draw the actual tracks there too and pour copper.

[QUOTE=LoneWolf_Recon;46904855]Looks like all the publicly available modules are discontinued ([URL="https://www.sparkfun.com/products/retired/10060"]C-Max's Receiver[/URL]), [URL="http://www.digikey.com/product-search/en?x=9&y=10&lang=en&site=us&keywords=561-1014-ND"]Digikey[/URL] has discontinued it as well. However you may be able to pull one from just about any [URL="http://www.leapsecond.com/pages/sony-wwvb/"]radio-time alarm clock[/URL]. [URL="http://www.joejaworski.com/wwvb/"]Here's[/URL] some more decoding processes for both the Phase modulation signal and the PCM signal. If you're lucky, you may be able to see if [URL="http://www.c-max-time.com/products/showProduct.php?id=2"]C-Max[/URL] has a few leftover in stock.[/QUOTE] I would totally salvage something if it was a personal project but I'm being graded on it and am afraid to. I guess I'll use a gps or wifi module.

Hey, FP! Finally I put some text on my LCD display. Took me a long time. I have regular cheap display on HD44780, 16 letters, 1 line. I used ATtiny2313 but I wasn't able to put text on it, doesn't know why, because I tried it on ISIS and everything was fine. But in real life I got only 8 squares. Then, I tried to connect display to ATmega8. It worked fine...But I have an issue. I can only put 8 chars. Every next char just dissapear, so only "half of display is working" (but look at the little square on the right). It'd be nice if anyone will help me to fix this. Also, this display has 16 pins on top and 16 pins below. My friend said it doesn't matter which pins I use. So, maybe another 8 characters doesn't displayed because I used only pins below? [IMG]https://pp.vk.me/c624023/v624023226/137a9/tztSV7-JXoY.jpg[/IMG]

A standard hookup with those displays only uses 10 pins on the display itself, that's not the problem. Don't know what the problem is though. I'd try driving it with an Arduino or some other easy solution, just for a bit, to see if the display is physically broken, or if it's your code.

[QUOTE=kolobok;46914631]Hey, FP! Finally I put some text on my LCD display. Took me a long time. I have regular cheap display on HD44780, 16 letters, 1 line. I used ATtiny2313 but I wasn't able to put text on it, doesn't know why, because I tried it on ISIS and everything was fine. But in real life I got only 8 squares. Then, I tried to connect display to ATmega8. It worked fine...But I have an issue. I can only put 8 chars. Every next char just dissapear, so only "half of display is working" (but look at the little square on the right). It'd be nice if anyone will help me to fix this. Also, this display has 16 pins on top and 16 pins below. My friend said it doesn't matter which pins I use. So, maybe another 8 characters doesn't displayed because I used only pins below? [IMG]https://pp.vk.me/c624023/v624023226/137a9/tztSV7-JXoY.jpg[/IMG][/QUOTE] The last 2 pins is for backlight, if you screen have it.

[QUOTE=AGMadsAG;46920396]The last 2 pins is for backlight, if you screen have it.[/QUOTE] I know, but it haven't one.

KeyShot 5 Rendering of Solid Edge model... beautiful! [img]http://i.imgur.com/PK7KjhK.jpg[/img]

Got my fakeass "Hakko" tips yesterday. Gave one a try, works fine, I'm just wondering how long one will last, probably not long. Anyone handled real tips? I'm wondering if there's any subtle differences in the packaging that would be a dead giveaway that they're fake. [t]http://i.imgur.com/n7Th3cx.jpg[/t] [t]http://i.imgur.com/ySy1jvO.jpg[/t] I'm assuming they're fake. But I mean, they have to be. They were a bit under a euro per piece. Edit: I just found something, yeah these are totally fake, so at least that's confirmed. Anyone want to take a guess at how long they'll last? Also, now I know that the Hakko tips fit perfectly on my station.

Relearning colpitts and general RF oscillators, and yet I'm confused. When designing a resonant LC circuit, do you shoot for an inductor that has a self-resonant frequency equal or very near the operating frequency of the circuit? I know impedance peaks there for the inductor, but isn't the gist to have little to no impedance of the inductor at resonance? Thus self-resonant frequency is only good for attenuating/filter circuits?

[QUOTE=LoneWolf_Recon;46937007]Relearning colpitts and general RF oscillators, and yet I'm confused. When designing a resonant LC circuit, do you shoot for an inductor that has a self-resonant frequency equal or very near the operating frequency of the circuit? I know impedance peaks there for the inductor, but isn't the gist to have little to no impedance of the inductor at resonance? Thus self-resonant frequency is only good for attenuating/filter circuits?[/QUOTE] You should keep in mind that an inductor also has some parasitic capacitance. That means that if you excite just the indcutor without anything else, it will be oscillating around the self resonant frequency. I think you can ignore it as long as the self-resonant frequency is way higher than your circuit's frequency, otherwise the impedance of the capacitance will drop into regions similar to the inductor's impedance.

is there any reason to buy from any local versions of dx.com like eud.dx.com? I ordered a screen from the eu website but it seems like it's still send from China anyways with a promise of a faster delivery...

Question, on a atx power supply there is a 5v power good wire which reports if the power is OK, I want to hook that up to my arduino but I probably can't just hook it to my arduino without any resistors right ? Can anyone help me a bit with this ?

You can, actually. What I would do though, is take the standby-wire (VUSB), not that wire, and use that. And I'd stick some capacitors in parallel with your Arduino, to smooth stuff out.

And make bloody sure you protect the 5v rail somehow (fuse for example) because if you short the output of an ATX supply you won't be happy.

[QUOTE=quincy18;46939839]Question, on a atx power supply there is a 5v power good wire which reports if the power is OK, I want to hook that up to my arduino but I probably can't just hook it to my arduino without any resistors right ? Can anyone help me a bit with this ?[/QUOTE] Actually [URL="http://pinouts.ru/Power/atxpower_pinout.shtml"]yes[/URL].