Newbie wants to build his own addon boards

[chwkrvn]

I'm interested in learning more about circuit design and soldering, so I thought I would try my hand at making my own addon boards for mister. I'm prepared to have a few broken parts and mishaps along the way, and worst-case scenario can just order from one of the more reputable sellers.

I decided the first board I'll try to make is the digital I/O board 1.2. I wanted to get some advice on how one goes about doing this. I know that I will need to get the PCB manufactured, but the part sourcing is quite confusing to me.

I'm trying to source as many parts as possible from Digikey to keep it easy for myself. As the wikis seem to be quite out of date, I loaded up the board design files in Altium's web viewer (https://www.altium.com/viewer/). I see a BOM like this:

Screen Shot 2021-06-08 at 7.41.18 PM.png (228.71 KiB) Viewed 2661 times

It is not super detailed, so I feel like I am kind of winging it just hoping I'm picking the correct parts to use at Digikey. For things like the SD card slot especially there doesn't seem to be any agreed-upon board placement amongst manufacturers, so i'm just buried in data sheets. I keep wondering if this is just how it goes, or do the addon board sellers figure this out in a smarter way? Not that I think what I make will come anywhere close to that quality

[aberu]

This is kind of the fun of it in terms of learning. Before the pandemic I knew none of this, then I was able to figure out what parts were needed within a few months of learning. I showed my BOM to Porkchop Express (misteraddons.com guy) and he said I basically came up with the same one as him (this is after months of learning about circuits, soldering, etc... just like you want to). Personally I go to digikey and I look at the schematic, and determine from there what I will order. And when I make a mistake, I learn something. I'm pretty sure all of the capacitors are x7r ceramic caps. If not it's only slightly more money and I don't think anything in the digital IO board would suffer if you went with ceramic caps that had less ripple (this isn't some intense design that is relying on x5r or something like that).

For the other stuff figure out the measurements to get the package size, and search on components sites like digikey or mouser using their advanced search to figure out what kind of parts those might be, and take your time learning about them and reading about them.

[C-R-T]

I haven’t been able to find a compatible Sd card slot from a normal source. Unfortunately the one used seems to be some kind of oddball no name part only available from Chinese sources…

[aberu]

I haven’t been able to find a compatible Sd card slot from a normal source. Unfortunately the one used seems to be some kind of oddball no name part only available from Chinese sources…

Yes, there are quite a few of the less critical parts which are sourced this way as Sorgelig doesn't live in the EU or NA and he specs things out to be affordable for DIY'ers.

[RetroP]

You could just ask a seller if they could sell you one in kit form. I often post out kit form boards to people.