Electrical Engineering V2 - Developers

[QUOTE=nikomo;46939997]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.[/QUOTE] I want to use the standby wire to power the arduino nano and then measure how long it takes after the switch is turned on for the standby wire to send power to the arduino. A typical atx power supply has to to it between 100ms and 900ms otherwise the ps is faulty. I have a lcd screen to display the results. [editline]15th January 2015[/editline] Something else I already made this with just leds but if I put a led without a resistor on the standby wire it starts really bright and then keeps dimming until its almost out. Looks like some sort of capacitor ? When I add the resistor it works fine

holy shit it works [img]http://i.imgur.com/h6nNHbU.jpg[/img] [img]http://i.imgur.com/Sn8JtrM.png[/img]

A circuit only a mother could love.

Those are some hefty resistors.

Woohoo, I just wrote a makefile that successfully compiles, links and binarizes my sourcecode for ARM Cortex M0 (STM32F0 in my case)! Now to also make it automatically flash the binary onto the MCU :) (Link in case anyone is interested: [url]http://pastebin.com/UKRENpxV[/url])

[QUOTE=papkee;46942477]Those are some hefty resistors.[/QUOTE] Pffft, I've got some 6.5W resistors that are larger than an RG6 cable.

[QUOTE=DrDevil;46942575]Woohoo, I just wrote a makefile that successfully compiles, links and binarizes my sourcecode for ARM Cortex M0 (STM32F0 in my case)! Now to also make it automatically flash the binary onto the MCU :) (Link in case anyone is interested: [url]http://pastebin.com/UKRENpxV[/url])[/QUOTE] Not enough CFLAGS, here's some for you: [code] CFLAGS="-g0 -DTT_CONFIG_OPTION_BYTECODE_INTERPRETER -pipe -O3 -march=pentium4 -fweb -funswitch-loops -funroll-all-loops -funit-at-a-time -fsched2-use-traces -fsched2-use-superblocks -fsched-stalled-insns=12 -frename-registers -fprefetch-loop-arrays -fpeel-loops -fomit-frame-pointer -fmerge-all-constants -finline-limit=32768 -finline-functions -ffunction-sections -ffast-math -fdata-sections -fbranch-target-load-optimize2" [/code] Flash sizes seem a bit small on those STM MCUs, I was expecting them to start at a minimum of 128KB. Then again, maybe I'm a bit spoiled.

[QUOTE=Cakebatyr;46943183]Pffft, I've got some 6.5W resistors that are larger than an RG6 cable.[/QUOTE] I've actually got a load resistor from a power plant rated at 500 watts. It's about the size of a pencil sharpener.

[QUOTE=ddrl46;46940039]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] Oke whoops, it wasn't the best idea to put it in another casing without some spacing between the underside of the board and the IRON case. Shorted out the 220v line and blew all the fuses:suicide:. Getting a new powersupply from a pc this evening and this time I wont remove the case

[QUOTE=nikomo;46943200]Not enough CFLAGS, here's some for you: CFLAGS Flash sizes seem a bit small on those STM MCUs, I was expecting them to start at a minimum of 128KB. Then again, maybe I'm a bit spoiled.[/QUOTE] Well, for my application 64K will be more than enough. I'm aiming for a low performance and thus low energy application.

I just had a quick look at [url]http://dirtypcbs.com/[/url] since I haven't checked them in a while, I think their pricing's dropped. You can get ±10 2-layer 5cm*5cm boards with HASL coating for $14 right now. And you get to pick the color instead of paying extra, but I'll hunt you down and kill you if you pick black. [QUOTE=DrDevil;46945867]Well, for my application 64K will be more than enough. I'm aiming for a low performance and thus low energy application.[/QUOTE] They've got 128K in the micros that they embed in microSD cards.

Black doesn't look too bad if it isn't glossy.

Yellow PCBs for everyone!

I like green and red, I can tolerate yellow and blue depending on the shades, and white is a bit specific, but it can totally work in some cases.

Once I get a project of mine working, is there someone who can teach me the ways of creating a proper PCB? I've been thinking of what I need for a while now and I honestly can't think of how I'd work it out (a 10p dipswitch where each output pin leads to an arduino input and a resistor EACH. How the hell would I do that without lines going over eachother?

Use through hole resistors, they're like massive jumpers. If you're doing signal or low-power traces, you can easily fit like, at least 6-8 traces under a resistor. And if you don't mind waiting the 2-8 weeks, do a double-sided board and get it done somewhere like OSH Park, Seeed Studio or Dirty PCBs. If you go double-sided, you can use a via to go through to the other side, so it's basically like magical wormholes 'n shit, and you can cheat your way around everywhere.

This is currently what my set up looks like. [t]http://i.imgur.com/pqOHVEZ.png[/t] [t]http://i.imgur.com/JPjg2gg.jpg[/t] It's a mystery why this hasn't shorted yet. Either way, in the top image, just act as if the push buttons are actually 2 switches :v:

With that many resistors in such a simple thing, it's basically a tracing free-for-all, you don't have to think about shit.

[QUOTE=nikomo;46957090]With that many resistors in such a simple thing, it's basically a tracing free-for-all, you don't have to think about shit.[/QUOTE] What do you mean? this is far from the final project. What I still have to add is an RJ45 connector (female), an op amp and possibly a Midi socket. The finished project isn't THAT big, but, it's not just this that has to get onto a PCB.

That's still real easy, especially if you make it a double-side board.

[QUOTE=nikomo;46957399]That's still real easy, especially if you make it a double-side board.[/QUOTE] Is 2 layers the same as double sided? Or am I wrong there?

2 layers = double sided. I'd learn how to use [URL="http://www.cadsoftusa.com/"]Eagle[/URL] or [URL="http://www.kicad-pcb.org/display/KICAD/KiCad+EDA+Software+Suite;jsessionid=7341E76771F82F23725629344DD42CDC"]KiCad[/URL] for making PCBs and schematics. They're both amazing tools, one made by a well-regarded company and the other an open-source project. It's a cool feeling when you get your first boards, solder them up and see them work.

I know everyone is saying go easymode and do it double sided, but I am 100% convinced with so few parts and so many through hole resistors you can do it single sided and I would suggest as long as you have time, you challenge yourself to make it as small as possible and single sided, purely because it's good practice should you need to make something bigger or more complex (and it really isn't that difficult). Additional bonuses include it will probably look neater and be cheaper to produce

[QUOTE=metallics;46959068]I know everyone is saying go easymode and do it double sided, but I am 100% convinced with so few parts and so many through hole resistors you can do it single sided and I would suggest as long as you have time, you challenge yourself to make it as small as possible and single sided, purely because it's good practice should you need to make something bigger or more complex (and it really isn't that difficult). Additional bonuses include it will probably look neater and be cheaper to produce[/QUOTE] Single sided boards aren't cheaper to produce. In fact, most PCB fabs don't produce single sided at all or will charge extra for single sided.

[QUOTE=DrDevil;46959802]Single sided boards aren't cheaper to produce. In fact, most PCB fabs don't produce single sided at all or will charge extra for single sided.[/QUOTE] Sure, but only if you're making an incredibly small number of them (I don't know of a fab that won't produce/charged more for single sided because it goes through the exact same process but they only copper one side). Single sided boards are absolutely cheaper to produce - whether you see this at the end depends upon the number you are ordering.

[QUOTE=metallics;46959898]Sure, but only if you're making an incredibly small number of them (I don't know of a fab that won't produce/charged more for single sided because it goes through the exact same process but they only copper one side). Single sided boards are absolutely cheaper to produce - whether you see this at the end depends upon the number you are ordering.[/QUOTE] Yeah, but they need to order single sided copper clad just for you, which will ultimately be more expensive to source and set up the machines for you. You'd need to order thousands of boards to make this worthwhile.

Single-side is a pretty common thing to have around larger production places. I've been doing nothing but single-side so far, and the Chinese love single-side.

What's the price for 10pcs of 5x5cm single sided?

Depends on who you get it manufactured from, I don't know any places off the top of my head that do single-sided in hobbyist quantities. I did say larger production in my post.

Is OSHPark the cheapest place to get low quantity runs of boards (<5)? I've searched around and haven't been able to find anywhere else that offers a low price for a low quantity of boards.