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If your are looking towards embedded:

* put a cap between power and ground

* get some nice ESD-birkenstocks

* don't listen to anybody telling you how it's done

The start of the art is BS and we need a revolution. There will be so many people who tell you that you can only do it in C and if you don't, you can't be taken seriously. The result is that everybody is keeping to C and nobody invests time in bringing new ideas to the field. The chip vendors stubbornly ship you really, really bad C SDK's and have no interest in doing better, for reason beyond my comprehension.

As you mentioned Rust - there is a Rust working group for embedded targets and they do cool stuff, but it's hard and a lot of work. Also, hardware is basically a huge block of global mutable state, so that is a problem to wrap ones head around.

But eventually we have to get rid of "C is the only serious option" which is an argument made by people who know how to write "safe" C and perpetuated by people who can't, but act like it.

[Before you react - I know this is an "extreme" statement and it's not 100% accurate and there is much more nuance to it - it is exaggerated for comic effect ;)]






regarding crappy SDK's from vendors - it is indeed strange they do not put more effort in this. I mean software is a huge cost in embedded as with other fields. My only theory is that it is usually the hardware team that decide what chip to use!? Would be interesting to know if respective tools for CAD/EE/hardware design is any better? (Hard to compare though)

The running conspiracy theory is that they want to sell you support via application engineers.

Could be a case of unfit business model leading to wrong incentives.


What would putting a single cap directly between power and ground be? Wouldn't that be a short circuit or boom?

A filter cap. It is in parallel to the actual load and once it's charged, there is not current anymore. It only booms when the voltage is to high.

Many chips, like a bluetooth chip, don't draw power continuously, but there are spikes. These spike in current can lead to the voltage dropping to low. A filter cap acts against that.

Sometimes, especially in prototyping circuits, where nobody took care of properly designing a power supply, filter caps are the first cheap shot at fixing weird behavior.

If you wanna know more, google the term, there is way better explanations then mine, form people with way more profound knowledge.


Capacitors do not conduct any current in steady state but rather conduct more current with higher frequency. The equation is i = C dV/dt

So depending on what frequencies you want to filter out you can change the capacitance C.


It's not a single cap. It's a cap near each power supply pin.

People already explained the reasons. I just wanted to add that point.




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