Common Parts Library | Hacker News Reader

Common Parts Library

octopart.com

123 pointssam35 comments

This is great. I am so glad this is getting done! I've spent way too much time clicking around the horrible distributor search engines, trying to determine which parts are cheap, readily available and will remain so (these three things usually go in hand). It is incredibly difficult and time-consuming if you are looking for something like a 12MHz SMD crystal: good luck sifting through thousands of options.

The current selection is very limited, but still useful for many projects, I will certainly make use of it.

The logical next step would be a KiCAD (and possibly Eagle?) library containing all the footprints. Not just thrown in there, or auto-converted, but actually verified by a human.

Thanks. Yes, footprints and symbols are on the roadmap. Since it's a limited number of parts, we'll be able to have well defined, reliable data there.

Please, please, PLEASE support KiCad with this! I use octopart pretty extensively and have loved it so far. I would be fanatical if you guys had KiCad footprints and symbols as it is the only decent EDA tool that is on all three major OSes.

I'll second the motion for KiCAD footprints and symbols!

There is not a good central repository for KiCAD parts, and on the client side the process for managing components or creating new ones is very convoluted. KiCAD is tremendously useful, but its creators need to take a serious look at usability. A cloud-based parts library would be a killer feature, along with drop-in public domain circuit "modules" (comprised of several to many connected components).

The development version of KiCad actually pulls the footprint library from github. It is significantly updated and quite a lot better than it used to be. Still has a long way to go, but it really is so much better than it was even a year ago.

@tomkinstinch - Chris here from WAi (contributor)

As Sam mentioned about, this is definitely something they'll be working on. If you use some of these parts and have a known working footprint, I'm sure they'd appreciate your help.

Well, it's not really on Mac. (not unless you count running the Windows version in VirtualBox of course)

This is the most promising installer at this point but it's still not very usable: http://discuss.wayneandlayne.com/t/new-os-x-builder/73/18

I have installed it on OS X before. The dev branch had problems installing on OS X, but as of today actually someone put up a dmg that supposedly works (I follow the KiCad dev list).

Are you talking about this thread? https://lists.launchpad.net/kicad-developers/msg14842.html Have you tried it?

Gotta say, there are lots of Kicad dmgs out there, but I have yet to see one actually work well. I'm not sure I've even seen one described as working well by the person posting it.

That is the thread I am talking about! Everyone on OS X seemed excited, but I'm not sure that means it is working well yet. I will reply here soon if it is a good installer.

Thanks! Waiting with bated breath. It's gonna be awesome once it happens but it's taken a long time...

@reportsingsjr - Chris here from WAi (contributor)

As Sam mentioned about, this is definitely something they'll be working on. If you use some of these parts and have a known working footprint, I'm sure they'd appreciate your help.

Totally awesome! Please also include additional things like camera sensors, displays, etc.

Can you explain more about the troubles you have in the distributor search tools? I assume you're speaking of distributors like Digi-Key and Mouser, right?

What kind of projects do you work on that finding things at Digi-Key and Mouser is not easy? What kinds of components are difficult for you to source?

If you're looking for specific types of components within a broader range (such as you want a < 10 ppm SMD crystal at a strange frequency), sure, I can see finding something like a suitable crystal being less than easy. But for normal components (everything Digi-Key sells is "normal" to me) I have a hard time understanding how changing Digi-Key's search tool would make it better.

Example: I needed to make a circuit with a logarithmic response to voltage that ran off single rail +5vDC. I needed about 200 copies of this configuration. I chose a low VCC rail-to-rail single-source op-amp from Digi-key. Twice. Both got EOL'd and impossible to get between the time I got my prototype done and the time I was ready to order in quantity.

Many ICs are produced for specific purposes for a short time and are never made again. As a "pro-am", its hard to navigate this part of the supply chain. Ostensibly a common part library would have smart people looking to make sure that a part remained source-able in the long term. If the idea became big enough, the CPL would cause these chosen parts to be so.

We hear stories like that all the time. That's exactly the trap we trying to help designers avoid.

@jwr - Chris from WAi here (contributor).

I couldn't agree more about having trouble finding the parts you want on disty search engines. The best thing to do is use the filters but even then it can be overwhelming. That's exactly why having a common parts library is useful. It just helps narrow your scope a bit. If all you need is a simple indictor LED then you're search is over. 1K resistor, done. It should take 80% of the effort out of building a BOM. The rest is obviously up to your specific design.

I agree, I would love an EDA extension. I think Octopart is thinking/working on this.

To start, this is a nice idea and I'm happy to contribute a bit to it, time depending and output depending. I'll be looking for an Altium library containing these parts and links in order to stay interested.

The 2N7002 has always been my standby signal NMOS. There are no power FETs or IGBT modules. Be nice to include some of the Ixys stuff.

A hinge-type micro SD card socket would be a nice variation, something that's harder to jar loose.

Hirose make some pretty nice board-to-board connectors. All you have on there so far are yucky 100 mil thruhole headers. Some finer pitch stuff would be nice. And pin pitch and number need to be a sortable/searchable field. Some SMB sockets would be awesome for test points, as would some test point headers (Vector makes nice ones like the K24 series, but my buddies like the little ones with the plastic colored bushing and a ring on top).

There are nowhere near enough microcontrollers. You could easily have 20 MSP430s. I've had good luck with the MSP430F2246 and F5438, I believe, but we've used a ton of different varieties.

How about a 232 driver like the MAX232 family? Or a 485/422 transceiver, or any kind of differential driver/receiver pair. Those Analog Devices ADUM isolated transceivers are great parts.

And no Zeners! The BZX84C series are a nice family to start with. I want to gag over the opamp selection.

I don't think the kinds of specs you offer are sufficient to describe the parts there. This could be said for just about everything on that list, which is probably the biggest issue with such a list. Most parts that designers select are chosen for one of two reasons - we don't care and they're in the library, or they are the key part that makes everything else worth doing. In the first instance, this list is great. In the second, I'm going to spend a day looking at all the vendor options to pick the best part I can find. But even for the parts I don't really care about, I have some concerns - the part has to work right for the application. Active parts are specified by many key parameters and in the case of opamps in particular these parameters are not indicated at all here, so I'll end up having to look up each part's details anyway. Consider input bias current, offset voltage, 0.1-10 hz noise, 10hz-1khz integrated noise, just as a start.

Rant off. Nice idea, here's my two cents worth.

+ for 2n7002

and why LPC1830? LPC1768 seems to be far more popular

More info about the Common Parts Library is available here, http://octopart.com/common-parts-library/about

This is great! A few things that might be nice to add are the ATmega32U4 (on the Arduino Leonardo and Micro, among other things), the ATtiny85, the ATtiny84, and these resonators: http://www.digikey.com/product-detail/en/AWSCR-8.00CV-T/535-...

For hand-soldering, it might be nice to include 1206 packages in addition to 0603 ones, although I realize that would make the list much longer.

Another good reference for this kind of thing is the Fab Lab inventory: http://fab.cba.mit.edu/about/fab/inv.html and it might be worth looking that over to see if there's anything that seems worth adding.

Thanks! Great suggestions. Stay tuned for updates to the list.

Ah, funny they mention the Open Parts Library-- we bought two for stock before figuring out that it's really a DFM kinda thing, which doesn't fit with the hobbyist customer segment at all. If anybody wants to buy one from a US-based distributor, you can certainly take them off our hands: http://www.robotmesh.com/open-parts-library-basic-v2?___SID=...

Awesome. We also need a repository of things that can be built solely with parts from the library. (ie "The 10 watt CPL boost regulator" etc).

Absolutely - we'd love to start collecting and highlighting CPL based projects.

Boost regulator might be difficult — my first observation was that there are no power inductors. These would be my next step, but unfortunately there would have to be at least several of those for them to be of any use.

I'd go with shielded 2.2µH/4.7µH/10µH/47µH/68µH/100µH SMD inductors, and definitely more than 1A.

For some reason, I thought it was related to GitHub and its octocats :) Nice concept.

Minor visual bug: http://octopart.com/#Resistors

'Case / Package / Footprint' input-with-dropdown border looks a bit different from other string inputs on the same page (FF 32.0.3).

Now you just need a prototyping service which has this standard library in stock, ready to be loaded into a pick and place machine.

It's amusing to see the world of transistors reduced to one general purpose transistor, and one FET, each in N and P polarity.

@Animate - Chris here from WAi (contributor)

That's our plan. We already have over most of them in our facility already. Where do you think a lot of the part numbers came from ;)

Now someone needs to write something like the Art of Electronics based on this component set.

This is pretty amazing

@helhawary - Chris here from WAi (contributor)

I'm glad you like it. Anything you particularly like or are disappointed that you didn't see?

No thermoelectric elements :(

@owenversteeg - Chris from WAi here (contributor)

Any recommendations?

Since you're partnered with Adafruit, you may want to list the two that they stock.

It looks like Octopart has these two:

http://octopart.com/tec1-12706-conrad-24165703 http://octopart.com/peltier1-velleman-12638546

The first is pretty standard, the second is overpriced and not sealed (which will cause it to break easier - not recommended. Don't list the second.)

I'd put in the "description" field the type (Thermoelectric Generator or Peltier Element) and then add a second field for the universal ID. You could also add a third field for voltage range or a fourth for the casing material type (commonly ceramic/silicone). Thermoelectric generators are more rare, so you may not find so many of those. (I can't find any of the partners selling them.) Using the universal ID allows you to easily find more of the same part, allows you to quickly identify a specific element, and allows you to quickly find the number of stages, number of thermocouples, amperage, size, and type. The vast majority of the time the universal ID will be printed on the Peltier element itself and will be the title of the product. For some weird reason one of the Adafruit Peltier elements has a strange, proprietary labeling system. (The two Octopart links and the other Adafruit one use the standard system.)

So, the table would look like

Description | Universal ID | Voltage Range | Casing | Link

Peltier Element | TEC1-12701 | 5V-7V | Ceramic+Silicone | http://www.adafruit.com/products/1331

Peltier Element | TEC1-12706 | 12V-15.5V | Ceramic+Silicone | http://www.adafruit.com/products/1330

Peltier Element | TEC1-12706 | 14V-16V | Ceramic+Silicone | http://octopart.com/tec1-12706-conrad-24165703

(I'm not listing the overpriced, unsealed one.)

Could you add a table like the one above? I'd love it. Peltier elements are very common, used in beverage coolers, lasers, computer coolers, watches - you name it, they're there. There are also just a few types of Peltier element that make up the market (three very common ones are listed above) so they are a perfect candidate for the library.

Universal ID diagram: https://upload.wikimedia.org/wikipedia/commons/4/47/Peltier_...

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