Replying to Avatar Dr. Hax

While I was looking for a "reference manual" for the STM32L442KC, I came across an option to buy the MCU directly from the manufacturer. I pay about $8/chip (about $9 after shipping). If I bought direct, $2.67/chip! The catch? I have to order 10,000 of them at once!

So, I'd need to be operating at an enormous scale for that purchase to make sense. $26,700 is a lot of money.

If I were operating at that scale, I could also buy all the other components at a better price per unit, but the main costs are

1. Software and hardware R&D

2. Hardware assembly

3. Parts

In that order, and there's a huge gap in between each one. Still, $5 less in parts, plus getting them direct from the manufacture is still pretty attractive.
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Dr. Hax 1y ago

I found that reference manual. It's 29.5 MB and 1600 pages. I sure hope it is well organized so I can find the one little thing I am looking for in there.

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Dr. Hax 1y ago

TL;DR I got the debug output from Signet's UART

- The reference manual is well organized!

- I added lots of comments to the code to reference which section of which document that it came from

- I got confused with calculating the UART BR register value for a desired baud rate, but that doesn't really matter because...

- The UART port "just worked" with `screen` on Fedora 38. I'm not sure if I transposed something in the command on my Debian 12 box or if they have different defaults for parity/stop bit, or something else is going on. I'm busy the next few days, but I'll boot that box again to investigate further in a few days

- The reason my previous test was constantly writing to the `screen` was because the debug output is continuous as there are apparently some debug print in the main loop

Overall, this is excellent news. Not only did I get the ability to see runtime debug print statements from the firmware, but I also got familiar with how to find low level information about this MCU.

Plus with the notes I made in the code, next time I'm going through it (or someone else is), it'll be easier to trarck these things down.

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