I find it a bit hard to believe that a whole microcontroller can be cheaper than a few electronic components on their own. Probably what did happen before the shortage was that the MCU was cheap enough and gave you a great flexibility in prototyping and coudl be suited for many different tasks. After the prototyping stage, it should've been replaced by simpler things, but since good enough was cheap enough, it was left as it was.
When it comes down to very simple microcontrollers with only a few pins, the package costs starts to dominate. Consider that each pin on an IC costs a few cents. If a small pincount MCU is replaced with a 555, some discrete logic, and passives for each of those ICs, it certainly can be more expensive to have discrete logic as opposed to an MCU, not to mention the higher cost from increase in PCB size for the extra components.
Yeah, I guess economy of scale means that you can manufacture 1,000,000,000 identical MCUs which are flexible and multi-purpose. Up to the point where you can't and it turns out some (most?) of them can be replaced by simple circuits with a few components.
Also remember that a bigger bill of materials in itself potentially complicates supply chain. The other thing that comes to mind is that more components may mean more passives or a more complex circuit.
> I suspect replacing the MCU with discrete components would have resulted in a more expensive product if there was no shortage.
And what? Complexity, and BOM size are not a problem by themselves alone. You should not view it in isolation from the context.
This is exactly the thinking which led the client running into this — "Trying to save money at any cost"
The point I make is that they easily spent a multiple times the price of this panel entire production run as a punishment for that.
Blinkey leds, and an interlock in between few buttons is really an overkill for MCU, and should've been treated as such no matter how many cents can be saved.
You can save a few dollars on a screwdriver if you can put in screws with a hammer, but you are certainly better off not doing that.
There are an infinite number of ways to make a project less fragile to changing market conditions. But you can't maximize all of it, it's all trade offs. Would making a project more resilient to semiconductor shortages increase vulnerability to other factors? Perhaps the increased electrical load pushes the battery requirements above the budgeted space. Perhaps the increased costs puts the product above the budget for customers, and making the project no longer viable in the marketplace. There are too many factors that I don't know about to possibly comment on all of it. The replacement of the MCU with discrete components was mentioned, and I commented on a few of the factors with could be involved with the decision, and did not claim to have made an exhaustive analysis of the product spec to determine why the choices were made.
> And what? Complexity, and BOM size are not a problem by themselves alone. You should not view it in isolation from the context.
Sure. So what's important about context? Is it impossible to have a 555 shortage?
> Blinkey leds, and an interlock in between few buttons is really an overkill for MCU, and should've been treated as such no matter how many cents can be saved.
Would you refuse to use 1% resistors if they were cheaper than 10% resistors? Overkill isn't bad by itself.
> You can save a few dollars on a screwdriver if you can put in screws with a hammer, but you are certainly better off not doing that.
It's more like a set of 100 drill bits being cheaper than the specific 20 you need all wrapped in individual boxes.
Sounds like it's more an issue of this work being outside the client engineer's competence than any kind of engineering breakthrough.
I suspect replacing the MCU with discrete components would have resulted in a more expensive product if there was no shortage.