Bitbanged USB stack on a sub-$1 Cortex M0+ MCU

January 5, 2017 in ARM, Devices, DIY, Hardware, Microcontroller, Tips & Tricks, Tutorial by admin

A nice presentation about how to get USB running on an sub-$1 Cortex M0+ ARM microcontroller that has no built in USB hardware. The talk describes the implementation of a new bitbanged USB stack, starting with a primer on the USB PHY layer and continuing up the stack, concluding with “Palawan”, a feature-complete open-source bitbanged USB Low Speed stack available for use on microcontrollers priced for under a dollar. We’ll go over requirements for getting USB to work, as well as talking about USB timing, packet order, and how to integrate everything together.