With little experience with electronics and comming from an Arduino background I am designing my first STM32 PCB.

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My question here is, since this is my first attempt, I would like to have some advice to check whether is anything wrong with this design? Are there any obvious flaws with it?.

  1. I want to make us of the ADC , are the ferrite beads placed correctly, should I use only one?
  2. Should I place more decoupling capacitors? I have seen designs with more of them and others with less.
  3. Why is the resistor between the resonator (R10) used for? Not all designs seem to include it.

I'd also be glad to hear general opinions about the design.

PS : It's a minimal design working on batteries, I have not included the regulator portion and other parts of the circuit as it's not relevant to the question.

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    \$\begingroup\$ Broad design review questions are not really encouraged here. Given that you have hardwired the boot pin, you need to bring NRST out to your SWD connector to recover from bad states, which even absent any intention to re-purpose the SWD pins fairly routinely happen inadvertently every once in a while in a system actively used for development. \$\endgroup\$ Aug 19 '19 at 4:32
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    \$\begingroup\$ I’m voting to close this question because it is an abandoned design review \$\endgroup\$ Dec 27 '20 at 3:54

1) Yes it looks good but it depends what are you using the ADC for and how big currents use the analog groun. If it is only for battery reading, it's overkil

2) Application notes suggest one small bypass capacitor per power pin pair and one large for digtal and one large for analog. Placement of large bypass near certain pair is sometimes mentioned.

3) Some devices need this bias resistors. Some don't and STM32 should have this built in. But it should work even if it is there.

NRST pin is not according to suggestions. It has internal pull up but it needs external capacitor.

Tying boot0 to ground disables serial bootloading. This is OK if you only use SWD.

Both crystals have 10pF load capacitors. Sounds weird, so double check if they are really calculated based on which crystals are chosen.

Double check if the battery measurement transistor circuit operates as inteded. Looks like it should be a PFET.

Sometimes buttons are pulling to ground so that there is no need to route 3V3 to button, if there is risk for short circuits.


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