BOMs for MasterBoard

Electronics
1

Hi!
First of all, thanks for the great work that went into this initiative!
I am currently looking to have the masterboard v2 assembled and got a little confused by the BOMs in the production files of the masterboard v2. Specifically, the parts listed under the ‘seeed_BOM’ and the ‘esp32_master_board.csv’ do not seem to be the same for each part. For example, the capacitors C4-C9 in ‘esp32_master_board.csv’ are listed as 0402 (imperial) sizes, whereas the seeed_BOM links to 0603 cases.

I checked the eagle file and it seems that 0402 is correct for C4-C9.
Still, both files list the 01005 sized part
0101ZC471KAT2A for C2, which looks like it should actually be an 0402 according to the eagle design.

So this got me thinking if I am maybe looking at the wrong files here or getting something else completely wrong ?
Thanks in advance and best regards
Moritz (Anyboby)

2

Hi Moritz,

I’m sorry for those mismatches. The file seeed_BOM was created for ordering from Seeed studio PCBA, but we never actually place an order here, so it is possible that there are some errors.

I’m quite busy these days, but I will try to watch the BOM and check all the component asap.
In the meantime, please rely on the eagle design file if you are able to open them.

Best,
Thomas.

3

Hi thomas,

If it’s of any help, I compared the seeed BOM with the regular BOM and also compared it to the eagle specs. I found the following parts to be divergent:

  • R17 is specified as 0603 in seeed BOM & regular BOM, but listed as 0402 in eagle
  • C2 is listed as a 01005 in seeed BOM & regular BOM, but listed as 0402 in eagle
  • C4-C9 are listed as 0402 parts in the regular BOM & eagle, but listed as 0603 in the seeed BOM
  • L, R1, R2, R3, R4, R20, R21, R5, R15, R16, R19, R22 list 100mW resistors in the seeed BOM, but are listed as 62.5mW resistors in the regular BOM and eagle files

Maybe that could speed the checking for you up :slight_smile:
PS: regarding C2, do you think CC0402KRX7R7BB471 would be a suitable replacement ? I was not sure what voltage capacitor would be appropriate for the LAN8720A here.

Best
Moritz

4

Hello Thomas,
I have recently order master boards too and found the same issue that C10, C11, C12 are wrong in their BOM document, with your last reply, I found the correct order number here.

Furthermore, the following items also needed alternatives suppliers as they were out of stock.

  • D1= The components are not available from Digi-Key. I found an alternative supplier here
5
  • D2= The components are not available from Mouser. I found an alternative supplier here
  • IC1= The components are not available from Digi-Key. I found an alternative supplier here
6
  • R10, R11, R12, R13= The components are not available from Farnell. I found an alternative supplier here
  • U$5= The components are not available from Digi-Key. I found the alternative supplier here

I cannot find any alternative supplier. I tried all the links on Octopart for Garmany,
IC2= The components are not available from Digi-Key.
SW1= The components are not available from Digi-Key.
U$2= The components are not available from Digi-Key.

Please help me or suggest to me what should I do, one idea is to wait and purchase these items and do the soldering by myself. I am not sure if it’s a good idea but I can give it a go in the worst case.

looking forward to hearing from you.

Best regards
Bilal

7

Hello,

The problematic components are

  • IC2 (DC/DC converter). Mouser is expecting to have them back in stock in October.
  • U$2 (LAN Controller). Mouser is expecting to have them back in stock in November.

We could redesign the board to use a different DC/DC converter but not using a different LAN controller since the firmware deeply depends on it.

I’m preparing a PR with an updated BOM correcting issues spotted by @anyboby (available on my fork for now)
I choose to remove the seeed BOM since it was created by hand and difficult to maintain.

Sorry for the (very) long delay to address those issue
Best,
Thomas.

8

Hi,

we are trying to order the master board with the updated BOM from Seeed Fusion PCB.

The MAX17502EATB+T is supposed to be available in mid October again.

For the LPS6235-153MRB which is currently out of stock, the company suggests to use the LPS6235-153MRC (note the change from B → C in the last letter). The company says:

C = 7″ machine-ready reel. EIA-481 embossed plastic tape (350 parts per full reel).

B = Less than full reel. In tape, but not machine ready. To have a leader and trailer added ($25 charge), use code letter C instead.

Would that work?

Best,
Julian

9

Hi @jviereck ,

Yes it will work. The two components are the identical, only the packaging is different. With the B option, they might have to place the part themselves on their assembly machine.

Best,
Thomas.

10

@jviereck do you have a final BOM that you used by chance with SEEED? Having trouble finding some parts such as C4-C9 and am curious as to what you ended up with. Also did you provide them instructions for a test?