In the schematic of STM32F030F4, the capacitor values are written 104, what is the unit of it?

[Prajnyajit]

I chose STM32F030F4 as MCU for my device. I have gone through its schematic (attached for reference). I have little doubt about it. The capacitor values are written 104, that's it. Please help me find its unit, I will be too much helpful.

Secondly, I have to connect two components to its PA9 (SCL/TX), and PA10 (SDA/RX). How to code them, because both will be connected to the same pins so will it cause an error?

[gbm]

10 plus four zeros picoFarad (100000 pF) -> 100 nF.

[Prajnyajit]

Thank you !

[Piranha]

It's 10E4 pF in E notation.

But such a format (like the "104") is not an universal standard for everything. It's just a case marking for some capacitors, while others can have different markings. Schematic must use normal notation like 100nF or 0,1uF. Therefore we can see that this particular schematic was drawn by someone, who doesn't understand what he is doing. He just sees the "104" on a capacitor and writes it down. And, of course, the NRST schematic is broken - R5 should be removed. Those "engineers" are just doing copy-paste and do not bother using their brain.

[Prajnyajit]

I understand. I thought I found it from https://stm32-base.org/boards/STM32F030F4P6-STM32F030-DEMO-BOARD-V1.1.html which is officially handled by STM too. Thank you.

[Piranha]

What does "officially handled" even mean? It's not ST's board, but just another Chinese board designed by dummies.

[Tesla DeLorean]

Perhaps read the manuals rather than copying a design? Or look at multiple designs to get a sense of what others do.

I wouldn't have a pull-up on BOOT0, might want to check the expectation the STM32F030F4 has

PA9/PA10 have assorted modes of operation, read the Data Sheet, this has a table indicating the Alternate Function options each pin has. They can only be connected to one peripheral at a time, but you get to choose which.

[Prajnyajit]

I didn't find many schematics over the internet but this one only.

[KnarfB]

In addition: there is a "Getting started with STM32xxx hardware development" for every series, containing and discussing reference schematics.

hth

KnarfB