It was BoM Hell, but the parts are ordered

I really need to find a parts inventory system suitable for personal use. I've been saying this for years, but this is getting difficult to manage.

This picture shows only the parts I've already accumulated for this project, not the parts I ordered this morning. So there will be more arriving.

While there are Python scripts to generate a Bill of Materials in CSV form from a KiCad schematic or board, that's the easy bit. There's a BoM column for the number of each component required for one board, but I'm planning to populate two boards. I added several columns to the spreadsheet:

• the quantity required for both boards
• the quantity currently on-hand
• the quantity purchased this time
• the quantity remaining after purchase

This last column showed in red if I didn't have enough of that part. This seemed a simple matter of looking at any line with red in the last column, and ordering enough to make it black. But then the fun started, because the entire column of "quantity currently on hand" was blank.

I've been accumulating parts from projects for almost two decades, and that doesn't count the miscellaneous stuff from before I got serious about my electronic insanity. The project to replace the PCB in a Canon P170‑DH calculator started in March 2016, almost four years ago. I've been building subsections of this design ever since, meaning I've been accumulating parts for almost as long. And I have no database of parts on hand.

I spent a good chunk of the weekend going through boxes of parts and reviewing old invoices trying to figure out what I did and didn't have. Sometimes that's an iterative process, like when I found an invoice indicating that I'd purchased two Halo TGM-210-NSLF transformers that I couldn't find, resulting in a search of my workshop that uncovered another box that I needed to inventory.

Then, because I hadn't fully enumerated the parts I wanted to use in KiCad, I had to manually search the Digi-Key site for the appropriate components and decide on quantities. Easy to do in ones and twos; agonizingly tedious when repeated 40 times.

And I do mean 40 times. I think that's how many individual line items were on this order. I'd intended to rationalize the parts to cut down on the number of different parts, but if I'd done that I wouldn't have gotten this done until next year. As it was I had to spend all Monday evening adding to my cart and didn't submit the order until after I woke up this morning. The "good news" is that all the parts I'd have to order from Mouser I already have on hand, so that's one less order to place.


There isn't much I can do more on this project until stuff starts showing up. The boards from JLCPCB have cleared US Customs and are supposed to arrive tomorrow. The Digi-Key order should show up Friday. Thinking about the last time I had to place an 0402 component, I bought a vacuum pick-up tool on Amazon which should arrive Friday as well. Maybe this weekend I'll get to actually build something!