4.7 The minimal circuit of a bare chip

I declare: solidlikelyshaky

1. Draw from memory the minimal circuit of a given chip (RP2040, STM32, ATtiny, CH32V003): supply, decoupling capacitors, reset, clock, programming lines.
2. Explain why a 100 nF capacitor near each supply pin, and what happens without.
3. Say which chip wants an external crystal or flash and which starts on its own.
4. Mount a bare chip on a breakout adapter or a first board and see it answer the programmer.
5. Choose a chip for a project by its peripherals, memory, voltage and price, and justify against two competitors.
6. Diagnosis: a bare chip not recognized by the programmer, supply, reset held, missing clock or boot pins; in which order to check.