BOM Shopping

daylanKifky

And it would be great if you can add a README or something inside the zip with the same instructions you give on the wiki. That way they won't get lost if people shares the zip.

HalloweenBob

Thank you. I will do that.

LesomeThataro

daylanKifky I ,myself, am in South Africa, so I'm currently working on putting together a purchase list where all components are bought from Mouser Electronics, in one shipment. They're based in England and so hopefully using them will be more convenient/economic for people in Europe/Middle East/Africa. In places where they don't have the exact component, I've used substitutes (they stock all the critical components). I'll upload as soon as I'm done (tomorrow), and hopefully I can get some critique on the purchase list just in case I've gone wrong in some instances.

HalloweenBob

If they do, indeed carry all the items on both BOMs, then maybe that should become the universal BOM, since Mouser has facilities here in the US as well. They just weren't priced as well as others on some items, but overall savings in time and shipping might still be worth it. The best way to be sure all substitutes are OK is to build up some boards and give it a test.

LesomeThataro

Okay, this is what I've managed to come up with for the K-Ceptors and hub. Due to price breaks, the numbers for the k-ceptors look about as pretty as those provided by HalloweenBob if one is looking to build exactly 15 k-ceptors (and you'll have extras). As for the hub, because only one is required, price breaks don't really help, and as a result, the hub here ends up roughly $10 over its price on the 2-supplier BOM that HalloweenBob has made for us.

I've made a note at the bottom of the spreadsheet in case the rationale behind the numbers isn't clear. Also, in places where there is a "Chordata BOM part #" and no "Real part #", that means that the component has not been substituted.

Another note is that this spreadsheet is based on the BOM dated 22/05/2019 12:43:20

daylanKifky

I think that separate BOMs coming from different zones is a great thing to have.
We will maintain an official, vendor neutral BOM. Pointing to a particular provider is kind of making publicity, and we don't want to do that. Unless of course a particular vendor is interested on sponsoring the project. Other, more specific BOMs will be published alongside with it on the documentation as contributed ones.

On the other hand, since you are taking the time to look for substitutes, there's no reason not to include them on the official BOM. That information would certainly help people trying to build the system. Unless, as @HalloweenBob said, they fail to give a working board when built. But for the passive components that improbable.

Here's an editable version of the BOM. Could you please include there a mention to the alternative components where applicable? If you do please post the new version here, and increment the number on the file by one.

Thanks to Both for your contributions!

HalloweenBob

Hi Lesome, I am currently trying to find the correct part number for J12 on the Hub, and I'm striking out. The part you listed for it: 629105136821 from Mouser seems to have an incompatible PCB Footprint compared to what is on the board. Could you double check that?

LesomeThataro

Hi, I got my parts about a week ago and this became quickly apparent while I was doing the soldering for the hub. Yeah, please strike it out. I'll look into finding a replacement with an appropriate footprint, but for now I've been able to find joy in the configuration that goes from the powerbank to the raspberry pi and uses its 3v3 rail pin to power the hub as it's shown here in the wiki. I'll revise the spreadsheet this weekend to get it to be more accurate, and I'll try add little things I've found useful thus far, like no clean solder paste, which has been the real star of the show for me, as someone with very little soldering experience.

HalloweenBob

Thank you! I will be looking here for info I have sent the drawing with measurements of the PCB footprint to 3 different suppliers who are all trying to find me a match.

The parts I have line up fine with the solder connections, but I would have to chop off the supports, which would cause it to break loose the first time the plug is inserted just a bit too hard.

So are you saying we don't need to use that jack, if we power it from the raspberry Pi without using the jack? Is that all it's for? just power?

LesomeThataro

HalloweenBob but I would have to chop off the supports, which would cause it to break loose the first time the plug is inserted just a bit too hard.

This was my exact experience.

HalloweenBob So are you saying we don't need to use that jack, if we power it from the raspberry Pi without using the jack? Is that all it's for? just power?

Yeah, it's used to power the system when using the recommended/favoured/safer configuration. A second configuration which is noted as being used mainly for testing purposes is also available. The second configuration presents a gotcha in that supplying a voltage equal to or greater than 5v on any pin on the hub is catastrophic. So it's important that some care is taken when wiring the sbc and hub using this approach (just make sure you're selecting the 3.3v pin to go from the sbc (pi) to the hub, as shown in the diagram on the wiki... never the 5v pin).

HalloweenBob

So I should assume that the power goes into that jack and then through a voltage regulator on the board when using the preferred method. I will keep looking for the right part, but someone should know what it is. There are completed boards out there. Can anyone who has already completed the Hub and used the right part please chime in? I am hitting dead ends everywhere. One of the companies I asked to look into this was Mouser. I explained that the most important criteria was that it fit into the PCB footprint.

The sent me this link as the part they claim will do the job. I looked at the datasheet and the footprint doesn't match. Is it close enough? It doesn't look it to me.

daylanKifky

@LesomeThataro @HalloweenBob Look at this answer for the correct part

HalloweenBob I should assume that the power goes into that jack and then through a voltage regulator on the board when using the preferred method.

That's correct. On the other configuration the power goes directly from the pin on Hub's J9 to the rest of the system. The fact that in the RPi the 3v3 and 5V pins are next to each other makes it easy to plug it the wrong way and potentially blow some KCs

HalloweenBob

I have just updated the BOM I have made as of 6-20-19. It's the same link that was in the first post in this thread. It includes several tabs including the attachments from the Official BOM as well as order forms (PO Forms) for Digi-Key and Wurth Electronics. I have found parts for everything on the Original BOM through just these two companies. I got everything I could from Wurth Electronics, because they were willing to give use excellent pricing on everything they carried in the hopes that many people would buy using this PO form to build their own sets of boards. The parts they didn't offer, I got from Digi-key as they had all the rest. Ordering is much simplified and shipping costs greatly reduced by simply ordering from 2 companies rather than12. Both these companies do ship world-wide so you can order from them no matter where you live. Just add your shipping info and adjust the quantities you want on the PO forms, print and scan them or make PDF's and email them to the email addresses included on the sheets. They will contact you for your payment info, and your parts will be on their way.

Mine have all been ordered and I am currently in the process of assembling the boards. I am getting help with the most difficult parts like U1 on the K-Ceptor, and a couple other very micro parts, but will be soldering all the rest in at home once that is complete. I will post on this forum with the results of my build when it is done, and list any time-saving procedures I find (if any) at that time. I will also post details on testing all the boards and whatever I had to do to accomplish that in hopes of saving others some time. Good luck. I think using this BOM will save you time and money, and I hope you find it useful.

konokaiden

This may be beating a dead horse, but I am about to solder all my parts together. I have ordered using Halloween Bob's excel file from the wiki, and noticed that the K-Ceptor was from version 2.2, while the boards I have are version 2.3..... So I went to the updated BOM, and found what I was missing. I also see R9 and R10 are not listed on either, yet they are on board 2.3. There is a very unclear table on the wiki, which makes it seem like I don't need to solder anything in R9 and R10 if I don't want to, or it gives a few possible resister values... so does anything go in those locations as of version 2.3?

It seems like the Hub hasn't changed since 1.2, so that was a relief, but I noticed that I have 15 K-Ceptors and my parts/locations aren't adding up to the KiCAD files, so I wanted to check in about this.

daylanKifky

Hi!
The R2.3 allow you to choose the KC's translation value between 3 preset resistor pairs (values 0, 1, or 2), or a custom one. The R9 and R10 are only used in case you want a custom translation value.
If you are planning to use the default_biped configuration you wont need to worry about these resistors.

konokaiden

@daylanKifky
Okay, thank you for clearing this up for me!

konokaiden

Last one, and I'm pretty sure the answer will be the same as for the R9-R10, but I just want someone to say it. J3 and J4, as well as JP1 - JP9, are those necessary for version 2.3 K-Ceptor, or are those for a previous/future model? And finally, same question for TP 1 - 11 on the Hub, are those required parts, or "room for fun"?

daylanKifky

HI!
the TP# are test points. Just exposed areas where you can place a tester or oscilloscope to troubleshoot the Board. So no component goes there.

The J3 and J4 allows you to use the KCeptors as an LSM9DS1 (the IMU in U1) breakout board. In general if you want to use it to capture the body that's not what you want and it's better to leave those footprints without components.

JP1 and JP2 allows you to bypass the LTC4316 address translator in U2 and also serve as testpoints.

You might wonder why all those footprints are there if they are not used in the end: up to this KCeptor model they were prototypal hardware. We added all these probes to help on our own development process.

konokaiden

Okay, I appreciate the explanation!

I've been updating the BOM that I have on my computer for the K-Ceptor 2.3 (download file was for v2.2 originally), and bits for the Hub. I'm trying to make a listing for everything that shows up on the KiCAD files so that when I (or someone else) references it later, everything is explained. I was assembling them today and found a few resistors which were changed to SMD instead of the previous THT, so outdated or unclear information is something I'm trying to eliminate in the files as I assemble my own set. The Hub is complete though, so I'll be setting up the Notochord soon. I've already got the Blender stuff ready, so I should know if my setup will work (at least the Hub) relatively soon!

I came here with absolutely zero experience with soldering and such, so this has been a fun learning process for me. YouTube videos were a quick and easy solution to learn about reflow and SMD, as well as THT (though I had gotten a cheap practice kit before I started this so that I'd have a little experience with THT). It wasn't super hard to find someone who would print the boards, though it took a little figuring out to get that set straight. But now I just need to get the BOM cleaned up and the ordering/assembling process should be completely up to date if someone wanted to put it on the wiki.

daylanKifky

konokaiden
Hi!
contributions to de documentation are always appreciated. Please let me know exactly which material are you preparing. A new BOM o explanations of the soldering process?

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