USB

• Let's learn USB! (2023)

A note on the above -- I now include the RP2040 chip on the Raspberry Pi Pico as an excellent candidate for learning USB.

I intended (back in 2020) to write my own USB device driver for an STM32 family chip, probably the STM32F411 and/or some other F4 chip in the STM32 family. These are ARM based microcontrollers, not that the CPU architecture particularly matters for the purpose of learning USB details.

So, I will unavoidably end up discussing specific aspects of the STM32 USB subsystem. And I will be writing a driver for a slave device, not a host driver as might be used in a linux or windows system.

• Introduction
• Sources of information
• Basics
• Basic Protocol
• USB "on the go"
• A peek at the STM32F411 USB
• Experiment 1 - minimal code
• Pins, GPIO, and alternate functions
• STM32 USB hardware setup
• What are these SOF interrupts
• Study other people's drivers
• receiving packets
• USB enumeration
• USB and byte order
• Sending data
• Interrupts
• Run some code

• ideas

• My old notes (2018 or older)
• My old linux USB notes