Texy wrote: ↑Tue Mar 23, 2021 5:38 pm
this could be my first "build my own partial kit", and the octopart BOM spreadsheet sure is a useful start, but...and bear with me as I am new to this, why are some of the parts not listed, or more specifically. those 17 amber LED's - what's so special about them that neither digikey, mouser, or future don't supply them? I'm hoping that I can fit whichever 3mm LED's I want to though, right?
The next problem looks like that SPI flash ship, W25Q80DVSNIG. Would be nice to get one of those within the UK, but Mouser, Digikey, Farnell and RS have them on back order or don't list them. Perhaps there is another source.....
Is this part of the fun of sourcing your own parts ;-)
Alas, a few manufacturers decided to discontinue those parts right after I put the BOM together, so I've been looking around for replacements as I use up the stock I have, and I'll update the BOM when I pick an official part.
In general, yes, you can use any LEDs with a similar voltage drop and brightness, though I'd stress that you should get diffuse lens LEDs or the module will be look pretty but be harder to use as which steps are on won't be as clearly readable from all angles.
The memory chip is pretty specific, it does need to be a winbond spiflash chip with the right footprint and 4kb sector erase. I've actually just ordered a few potential alternates and will update the BOM if one of them works properly.
- W25Q80DVSSIG - same chip with slightly wider footprint. should be drop-in the same, but might not be solderable on the existing footprint without hot air and paste
never mind, this is actually a 2.2v chip, would need a different regulator
- W25Q40CLSNIG - 4mB version of the chip, should be compatible as the memory capacity isn't close to maxed, but I want to test this myself and make sure the firmware behaves properly