AVR Lab

👽 Template and Examples in C for AVR Microcontrollers, optionally built via Docker.

• Using default gcc-avr and avr-libc, see Dockerfile for details
• Mainly written for ATtiny85, if not stated otherwise
• Check out the examples in src/
• Utilize existing code for an own project or start with a basic example
• Having Docker in place, the projects can be built with a single command

Examples and Helper Modules

Example projects, roughly sorted by complexity.

Example	Code	Info
blink	src/blink/main.c	Hello world blink example
timemeas	src/timemeas/main.c	No delay blink example using time measure
togglebutton	src/togglebutton/main.c	Debounced button input
states	src/states/main.c	Simple state logic with debounced button input
sleep_pci	src/sleep_pci/main.c	Sleep and wake-up via pin change interrupt
ws2812	src/ws2812/main.c	WS2812B control via Bit-Banging

Helper modules.

Module	API	Code	Info
debounce	src/debounce.h	src/debounce.c	Button debouncer
timemeas	src/timemeas.h	src/timemeas.c	Time measurement
ws2812b_attiny13	src/ws2812b_attiny13.h	src/ws2812b_attiny13.c	WS2812B interface. 3rd party, see below
zzz	src/zzz.h	src/zzz.c	Power down sleep mode

Set up Docker

A Docker installation and basic Docker knowledge is required. Run these commands in the repository root.

First, build the Docker image (once).

docker build -t avrlab .

Build a project

This builds a project in an auto-removing container, from the image created above. Recommended in most cases.

# Bash
docker run --rm -v $(pwd):/code avrlab /bin/bash -c "cd src/blink && make hex"

# Powershell
docker run --rm -v ${PWD}:/code avrlab /bin/bash -c "cd src/blink && make hex"

Advanced (more Control over Container)

Start container with interactive shell.

# Option 1: Auto-removing container after usage
# Bash
docker run --rm -it -v $(pwd):/code avrlab

# Powershell
docker run --rm -it -v ${PWD}:/code avrlab

# Option 2: Named container
# Bash
docker run -it -v $(pwd):/code --name avrlab_01 avrlab

# Powershell
docker run -it -v ${PWD}:/code --name avrlab_01 avrlab

# For option 2, start container like this
docker start -i avrlab_01

Build a project.

cd src/blink
make hex

avrdude Example Commands

• Install avrdude on host (recommended)
• Use stk500v1 compatible ISP (e.g. using Arduino with ISP example sketch)

Program

avrdude -p attiny85 -P com3 -c stk500v1 -b 19200 -U flash:w:main.hex

Fuses

Attention: inappropriate fuse settings can brick the microcontroller, check [1]

# Set 1MHz clock
avrdude -p attiny85 -P com3 -c stk500v1 -b 19200 -U lfuse:w:0x62:m

# Set 8MHz clock
avrdude -p attiny85 -P com3 -c stk500v1 -b 19200 -U lfuse:w:0xE2:m

References

[1] https://www.engbedded.com/fusecalc/

License

The source code in this repository is licensed under the MIT license (if not stated otherwise). For Licenses of thirdparty components, see below.

Thirdparty

Makefile_template

• origin: WinAVR-20100110
• license: see Makefile_template
• each example project in src/ contains a Makefile, which is an adjusted copy of Makefile_template

ws2812b_attiny13

• version: a98438c
• origin: https://github.com/dsprenkels/ws2812b_attiny13/tree/a98438c8b0572c430f73fb759fdab2607b238586
• extracted from origin:
  • LICENSE
  • ws2812b_attiny13.{c,h}
• modifications are marked with AVR_LAB
• license: src/ws2812b_attiny13_LICENSE