README.md

Chapter 4: Input, Output, and Timers

This is a companion repository for Making Embedded Systems, 2nd Ed. by Elecia White.

Following Along in the Book

Some example processor documents, obtained from their vendors:

• ATtiny AVR Microcontroller Datasheet (remote) and the application note AVR 130: Setup and Use the AVR Timers

• TI MSP430x2xx User's Guide (remote)

• STM32F103 Reference Manual (remote) and github repository, specifically stm32f103x6.h

Timer Calculations

Showing my math for the timer calculation section:

• Timer calculations
• Timer flowchart

See also STM32 Delay Microsecond Millisecond Utility: a blog post about different ways to set up timer delays

Debouncing

A Guide to Debouncing by Jack Ganssle. Hackaday has code for multiple different implementations

Hex and Bits

For understanding and practicing hex and bitwise operations:

• YouTube: Bit Hacks from Beginner to Advanced is an excellent video
• calc.50x.ca provides a hex calculator showing the binary values
• bitwiseCmd lets you try out bitwise operations online
• For more bit twiddling hacks and seeing how you can do optimal things (usually at the cost of readability), check out Stanford Graphics Bithacks

Code For This Chapter

• PWM on Raspberry Pi Pico, example on Wokwi

• More complex PWM on Raspberry Pi Pico example on Wokwi

• FIXME: Button interface with debouncing

• FIXME: Dependency injection example

Final Note

If you like what's here, please consider buying the book: Making Embedded Systems, 2nd Ed. by Elecia White