Electrical Engineering V3

[woidoi]

[vid]https://dl.dropboxusercontent.com/u/43645231/photos/electro/Game%20of%20Life.webm[/vid]

Got game of life on a charlieplexed array. I used a library to drive the array, but figured out the Game of life algorithm myself.

I'm gonna look at running this on one of those 128x64 tiny OLED screens, it should be fine unless my code is an unoptimized mess :v:

[Leystryku]

[QUOTE=haloguy234;50893377]Recently I finished building a nixie tube clock. I didn't make any of it myself, I bought a kit for it. But it was good fun to put it all together and solder everything. A couple of days ago I also built a cheap oscilloscope. Probably going to make a lot of you guys cringe but for basic use like measuring duty cycles and such, it's okay. I'm not so hardcore into this at the moment that I need a $400 scope.

My next project is going to be building a CNC machine and hopefully a 3D printer out of an inkjet printer and scanner husk, and some steppers out of floppy drives for Z-axis control. Then hopefully have it sturdy enough for milling so I can have everything I need to mill my own PCBs (I hate perfboards).

[img_thumb]http://i.imgur.com/C5RridC.jpg[/img_thumb]
[img_thumb]http://i.imgur.com/xjGGARV.jpg[/img_thumb]
[vid]https://my.mixtape.moe/miocvq.mp4[/vid][/QUOTE]

This reminds me of the divergence meter from steins gate :v:
[img_thumb]https://avvesione.files.wordpress.com/2011/07/steinsgate-14-divergence_meter-suzuha-time_travel.jpg[/img_thumb]

[DrLuke]

Look at what my university was about to throw away:

[t]https://my.mixtape.moe/cyygrz.jpg[/t]

In the right slot is a 'standard' 50Ghz sample aquisition card, and on the left is a 2 channel 20GHz TDR that can also be used as a VNA.

Our hackerspace just gained a fucking DC-20GHz VNA.

[Cakebatyr]

So I'm currently planning on building my own 1.420GHz radio telescope and am currently planning on how I'm going to do the filtering.

I could spend $100 on an assortment of filters (currently looking at 850MHz HPF, a 500-520MHz LO mixer/downconverter and a 900MHz bandpass filter), or I could start designing my own filters.

[t]https://i.imgur.com/OFk4it4.png[/t][t]https://i.imgur.com/O9iJ5NX.png[/t]

Looks good, but that teeny tiny inductance value is going to be kind of a pain.

But I think I could get away with some 1.42GHz bandpass filters made from [url=https://en.wikipedia.org/wiki/Distributed_element_filter]stripline[/url], the issue is that lambda/4 of 1.42GHz is ~52.5mm so its going to be a rather large board.

Guess I'll be going with the inductive/capacitive filters over stripline. [del]By my math it looks like I'll need 2*1nH+3nH+10nH inductors in parallel.[/del] That math is off by an order of magnitude. Guess I'll build my original idea of filters for downconversion.

[editline]b[/editline]

Ok back to the downconversion plan:

[t]https://i.imgur.com/Hs7HCvV.png[/t][t]https://i.imgur.com/9feyed7.png[/t]

A nice 1000MHz HPF with friendly component values. From here I can use readily available 433MHz bandpass filters to further increase isolation.

-28dB down at 800MHz, should be good.

[aydin690]

You guys know if there's a fab house that can do custom weird plated via holes? Like only one half of the circle being plated or even one third?

[DrLuke]

[QUOTE=aydin690;50915199]You guys know if there's a fab house that can do custom weird plated via holes? Like only one half of the circle being plated or even one third?[/QUOTE]

I think you'll have a hard time finding that due to the way vias are made. The only way I imagine that could work is to route the hole apart after plating, but that can potentially ruin you entire via.

May I ask what exactly you try to accomplish?

[paindoc]

So while the pay working in the space industry is sorta awful, one of the neatest things is getting to submit proposals for things I'd like to work on. The DoD (mostly DARPA) or NASA will put out a request, and I can write a proposal and if we win it I get to work on it.

I've been looking for opportunities to submit proposals for better infantry armor solutions, and may have found one. It'd mostly he a helmet with a HUD if I'm understanding it right, but hey writing the proposal is neat and if we win an initial bid I get to kludgineer some sci fi looking helmet :D

Also, one of our EE guys sent me home with a xilinx board to play with, so that's what I'll be doing this weekend. Never touched an fpga board, so I'm pretty excited to do so

[aydin690]

FPGA's and CPLD's aren't very fun.

[editline]19th August 2016[/editline]

[QUOTE=DrDevil;50915498]I think you'll have a hard time finding that due to the way vias are made. The only way I imagine that could work is to route the hole apart after plating, but that can potentially ruin you entire via.

May I ask what exactly you try to accomplish?[/QUOTE]

Yeah, i figured. Even if i do plated half holes, they're not going to be as small as i want them. Looks like i'm spending the next few days in the clean room.

I do MEMS and microfabrication, it's going to be some sort of weird heat sink with an industrial diamond on the other side.

[DrLuke]

[QUOTE=aydin690;50915577]
Yeah, i figured. Even if i do plated half holes, they're not going to be as small as i want them. Looks like i'm spending the next few days in the clean room.

I do MEMS and microfabrication, it's going to be some sort of weird heat sink with an industrial diamond on the other side.[/QUOTE]

If you have the dosh to spend I'd just hit up some companies... I'm sure they can try to make something work, but expect to pay loadsa money.

[TCWilliamson]

[QUOTE=aydin690;50915577]FPGA's and CPLD's aren't very fun.

[editline]19th August 2016[/editline]

Yeah, i figured. Even if i do plated half holes, they're not going to be as small as i want them. Looks like i'm spending the next few days in the clean room.

I do MEMS and microfabrication, it's going to be some sort of weird heat sink with an industrial diamond on the other side.[/QUOTE]

Oh Cool, I'd love to get into microfabrication.

I've brought a Turbomolecular pump and Varian backing pump. Planning on 'playing around' with Sputtering and some other interesting techniques.

How about Having a completely plated hole, then etch away what you don't want by the same method they manufacture the board? (coat with UV resist where you don't want the copper, expose, then etch before cleaning?)

[paindoc]

[QUOTE=aydin690;50915577]FPGA's and CPLD's aren't very fun.

[editline]19th August 2016[/editline]

Yeah, i figured. Even if i do plated half holes, they're not going to be as small as i want them. Looks like i'm spending the next few days in the clean room.

I do MEMS and microfabrication, it's going to be some sort of weird heat sink with an industrial diamond on the other side.[/QUOTE]

They're not terribly fun, but they have neat applications. I had thought of using one to create an analog modelling synth a while ago, which a couple of synthesizer companies have actually been doing lately. They're instrumental for some of the work I do, too.

[hakkoru]

[QUOTE=aydin690;50915577]FPGA's and CPLD's aren't very fun.

[editline]19th August 2016[/editline]

Yeah, i figured. Even if i do plated half holes, they're not going to be as small as i want them. Looks like i'm spending the next few days in the clean room.

I do MEMS and microfabrication, it's going to be some sort of weird heat sink with an industrial diamond on the other side.[/QUOTE]

idk i really enjoyed using fpgas

[editline]19th August 2016[/editline]

oh hey since i have money now i might buy that cheap fpga i was eyeing

[editline]19th August 2016[/editline]

[img]http://i.imgur.com/YfxRWef.png[/img]

excellent

[Cakebatyr]

Oh you must be buying something from Adafruit.

[DrLuke]

[QUOTE=DrDevil;50895703]Look at what my university was about to throw away:

[t]https://my.mixtape.moe/cyygrz.jpg[/t]

In the right slot is a 'standard' 50Ghz sample aquisition card, and on the left is a 2 channel 20GHz TDR that can also be used as a VNA.

Our hackerspace just gained a fucking DC-20GHz VNA.[/QUOTE]

So turns out that in order to use the TDR-Card as a VNA you need special software that costs [b]11.000$[/b]! Oh, and also, the software requires an upgrade from windows 2000 to windows XP... I never thought I'd ever upgrade something from 2000 to XP in my lifetime :v:

We will probably request the 30-day trial from tektronix and see if we maybe can make it work for more than 30 days *cough cough*

[LoneWolf_Recon]

Sooooonnnn :excited:

[IMG]https://sites.google.com/site/lonewolfscircuits/sitefiles/MOSIS_pad_connections.png[/IMG]

[img_thumb]https://sites.google.com/site/lonewolfscircuits/sitefiles/RiseDFF_Layout.png[/img_thumb]

[QUOTE=aydin690;50915199]You guys know if there's a fab house that can do custom weird plated via holes? Like only one half of the circle being plated or even one third?[/QUOTE]

Yeah you'd have to shell out a decent amount to get half-plated vias, a janky solution I'd recommend is just use conductive ink and paint a half of the via yourself.

[QUOTE=paindoc;50915567]So while the pay working in the space industry is sorta awful, one of the neatest things is getting to submit proposals for things I'd like to work on. The DoD (mostly DARPA) or NASA will put out a request, and I can write a proposal and if we win it I get to work on it.

I've been looking for opportunities to submit proposals for better infantry armor solutions, and may have found one. It'd mostly he a helmet with a HUD if I'm understanding it right, but hey writing the proposal is neat and if we win an initial bid I get to kludgineer some sci fi looking helmet :D

Also, one of our EE guys sent me home with a xilinx board to play with, so that's what I'll be doing this weekend. Never touched an fpga board, so I'm pretty excited to do so[/QUOTE]

Congrats, glad to hear it dude. FPGAs are fun things to work with, even if the Xilinx IDEs are a bit of a clusterfuck.

[pentium]

[QUOTE=DrDevil;50918504]So turns out that in order to use the TDR-Card as a VNA you need special software that costs [b]11.000$[/b]! Oh, and also, the software requires an upgrade from windows 2000 to windows XP... I never thought I'd ever upgrade something from 2000 to XP in my lifetime :v:

We will probably request the 30-day trial from tektronix and see if we maybe can make it work for more than 30 days *cough cough*[/QUOTE]

I seem to recall Hackaday used to have a page on how to forge the security dongles and basically unlock the entire unit..

Or, they did before Tektronix DMCA'd everything they could find.

[andreblue]

[QUOTE=pentium;50921736]I seem to recall Hackaday used to have a page on how to forge the security dongles and basically unlock the entire unit..

Or, they did before Tektronix DMCA'd everything they could find.[/QUOTE]
This one right? [url]http://hackaday.com/2014/07/28/cloning-tektronix-application-modules/[/url]

If so [url]https://www.scribd.com/doc/236065278/Cloning-Tektronix-Application-Modules-pdf[/url] seems to have the details and the PCB is at [url]https://oshpark.com/shared_projects/pE9Ff8iu[/url]

[Ddrl46]

[QUOTE=pentium;50921736]I seem to recall Hackaday used to have a page on how to forge the security dongles and basically unlock the entire unit..

Or, they did before Tektronix DMCA'd everything they could find.[/QUOTE]
Those are for their more mainstream TDS/DPO/MSO 3000 and 4000 series. This series of scopes is a bit different.

There is some information on the eevblog forum about someone activating the options on a CSA 7000 / TDS 7000 however: [url]http://www.eevblog.com/forum/testgear/tek-csa7404-repair-project/[/url]

[DrLuke]

[QUOTE=pentium;50921736]I seem to recall Hackaday used to have a page on how to forge the security dongles and basically unlock the entire unit..

Or, they did before Tektronix DMCA'd everything they could find.[/QUOTE]

Yeah that's something completely different though. (The article is still available in the [url=https://web.archive.org/web/20140728140425/http://hackaday.com/2014/07/28/cloning-tektronix-application-modules/]wayback machine[/url])

We'll probably just download the software and patch out the check for the hardware key with a disassembler.

[fenwick]

[QUOTE=The Salmon;50821570][video=youtube;07EctdVlX0w]https://www.youtube.com/watch?v=07EctdVlX0w[/video]

2nd year student here strange question: I want to implement the mechanism in the above product (not the midi part) on a smaller scale -- would an actuator be the way to go here? are there other components that make percussive strikes like this? ideally i want to be able to control when it hits and how hard it hits a thing.[/QUOTE]

You want a solenoid, something like this probably:

[url]https://www.sparkfun.com/products/10391[/url]

[GaryJS]

Finally got a chance to troubleshoot my 3d printer kit build. One of the RAMPS (stepper motor driver boards ) is DOA. Contacted seller to send me a new one last night. But i still bought a pack of 5 with heat sinks for like $6 for backups as ive heard theyre a common point of failure.

[Metallics]

[QUOTE=gjsdeath;50926620]Finally got a chance to troubleshoot my 3d printer kit build. One of the RAMPS (stepper motor driver boards ) is DOA. Contacted seller to send me a new one last night. But i still bought a pack of 5 with heat sinks for like $6 for backups as ive heard theyre a common point of failure.[/QUOTE]

I've had 2 printers for nearly 6 years now and never had one fail?

[editline]22nd August 2016[/editline]

Tend to have more trouble with unreliable clanky bits like bearings

[samh]

[QUOTE=fenwick;50924756]You want a solenoid, something like this probably:

[url]https://www.sparkfun.com/products/10391[/url][/QUOTE]

thanks for the response but I actually came to this result myself on the weekend aha

[GaryJS]

[QUOTE=metallics;50927977]I've had 2 printers for nearly 6 years now and never had one fail?

[editline]22nd August 2016[/editline]

Tend to have more trouble with unreliable clanky bits like bearings[/QUOTE]

I heard they tend to heat up a and can get wonky. So I thought some with heat sinks may help. The heat sinks alone would've been like 3-4$ so i might as well get the ones with RAMPS.

[Zero-Point]

I recall looking at the RAMPS boards at some point, they seemed somewhat under-powered in my mind, but then I like to over-engineer things.

[GaryJS]

[QUOTE=Zero-Point;50928583]I recall looking at the RAMPS boards at some point, they seemed somewhat under-powered in my mind, but then I like to over-engineer things.[/QUOTE]

I might end up replacing them with something that can handle higher current. But what ever it ends up being I'd prefer it to be a drop in replacement.

In case I haven't mentioned it already. The printer is a Geeetech Aluminum Prusa Mentel I3. The main board is this: [url]http://reprap.org/wiki/Sanguinololu[/url]

[DrLuke]

[quote=Tektronix]
If you really want to install these software on your instrument, you can buy a new mainframe.
[/quote]

Thanks guys!

[paindoc]

Don't look at the schematic for the RAMPS board, its pretty much as bad as a design can be. The thing just about [I]literally[/I] couldn't be made ot be noisier.

Drivers are a common point of failure. Make sure they aren't overheating and set your current to be the minimum it can be for the drivers to move, too. Microstepping being too high can increase current draw too - 1/16th is the highest you should be on a RAMPS board.

If you can, move to something like smoothieboard soon. Smoothie firmware is seeing a lot of use now and is being adopted by a number of other board manufacturers, and there are even smoothieboard clones. The firmware update process is way easier for these boards, and the config files can be unchanged between firmware updates.

They also have software trimpots, so you use your stepper motor spec sheets to set the current draw in your config file. Combine that with thermal vias that aren't retarded, and the smoothieboard won't eat any drivers.

[editline]22nd August 2016[/editline]

if you have any further questions about 3d printing hmu. its pretty much my entire job to maintain our companies 7 3D printers, from monoprice clones, ultimakers, repraps, to a really big proprietary machine

[Ddrl46]

So we had an excuse to take the covers off of an Agilent E8364B 50GHz vector network analyzer today...

[thumb]http://i.imgur.com/ToAsXvm.jpg[/thumb]

[thumb]http://i.imgur.com/MsggkvC.jpg[/thumb]

[TCWilliamson]

[QUOTE=ddrl46;50929965]So we had an excuse to take the covers off of an Agilent E8364B 50GHz vector network analyzer today...

[thumb]http://i.imgur.com/ToAsXvm.jpg[/thumb]

[thumb]http://i.imgur.com/MsggkvC.jpg[/thumb][/QUOTE]

Y'd think for the price of the unit that they would use better cable management techniques.