Issues

• Feature request Fast Start flags (github noob sorry)

  SpenceKonde/ATTinyCore#930 · Filter by author aussiechip opened on Sep 7, 2026

• Updating Arduino AVR Boards package in IDE breaks ATTinyCore

  SpenceKonde/ATTinyCore#929 · Filter by author Simulators opened on Sep 3, 2026
  1

• Drazzy.com SSL certificate expired (X509 error in arduino-cli)

  SpenceKonde/ATTinyCore#928 · Filter by author hoangduy1505 opened on Jun 30, 2026
  4

• Installation failed - micronucleus

  SpenceKonde/ATTinyCore#926 · Filter by author slepnoga opened on Apr 10, 2026
  1

• TinySoftwareSerial RX is broken in 2.0.0

  SpenceKonde/ATTinyCore#925 · Filter by author MCUdude opened on Mar 15, 2026

• ATTinyCore install fails – azduino.com micronucleus download refused

  SpenceKonde/ATTinyCore#924 · Filter by author GabrielY1212 opened on Mar 13, 2026
  3

• ATtiny84a upload errors

  SpenceKonde/ATTinyCore#923 · Filter by author Jimbolaya64 opened on Feb 16, 2026
  2

• Sleep not shutting down fully

  SpenceKonde/ATTinyCore#921 · Filter by author JulesGren opened on Jan 27, 2026
  2

• ATTinyCore Board Download Error - 3.218.2.136:443: connect: connection refused

  SpenceKonde/ATTinyCore#919 · Filter by author dd6ds opened on Jan 10, 2026
  17

• Boot Entry mode menu

  SpenceKonde/ATTinyCore#918 · Filter by author gromdar opened on Jan 1, 2026

• (Manual) Installation of ATTinyCore v2.0.0 on Arduino IDE v2.3.6

  SpenceKonde/ATTinyCore#915 · Filter by author GiorgosXou opened on Dec 21, 2025
  5

• Problem Installing ATTinyCore on Arduino IDE 2.3.6

  SpenceKonde/ATTinyCore#913 · Filter by author Mauro5049 opened on Oct 9, 2025
  10

• failed to verify certificate on https://azduino.com/bin/micronucleus/micronucleus-cli-2.5-azd1-x86_64-linux-gnu.tar.bz2

  SpenceKonde/ATTinyCore#912 · Filter by author ArminJo opened on Oct 8, 2025
  4

• Please document prevenance of bundled hex bootloaders

  SpenceKonde/ATTinyCore#906 · Filter by author Github-Home-User opened on May 26, 2025

• [Bug] Upload with micronucleus fails with space in build path

  SpenceKonde/ATTinyCore#904 · Filter by author smlz opened on Apr 1, 2025

• Blink sketch Attiny84a delay issue

  SpenceKonde/ATTinyCore#903 · Filter by author ITstreet1 opened on Mar 28, 2025
  5

• Any chance the TTtiny26L support to be added

  SpenceKonde/ATTinyCore#899 · Filter by author bmitov opened on Mar 8, 2025

• Third party source added to board manager but cant find attiny core library anymore

  SpenceKonde/ATTinyCore#898 · Filter by author lupusworax opened on Feb 22, 2025
  3

• The Pinout for the ATtiny828 is missing

  SpenceKonde/ATTinyCore#895 · Filter by author bmitov opened on Jan 11, 2025

• Problem Installing ATTinyCore on Arduino IDE 2.3.3

  SpenceKonde/ATTinyCore#891 · Filter by author VitorOM opened on Nov 29, 2024
  12

• https://drazzy.com/package_drazzy.com_index.json - SSL-certificate expired 3 days ago

  SpenceKonde/ATTinyCore#885 · Filter by author realvinx opened on Oct 24, 2024
  36

• digitalWriteFast is broken on most platforms...

  SpenceKonde/ATTinyCore#884 · Filter by author WestfW opened on Oct 24, 2024

• Malloc problem

  Criticalhelp wantedmystery
  SpenceKonde/ATTinyCore#863 · Filter by author FroggyCorp opened on Jun 3, 2024
  3

• Help with Attiny85 RX Uart Pin

  SpenceKonde/ATTinyCore#862 · Filter by author GabrielSCorrea opened on Jun 1, 2024
  3

• Cannot upload bootloader to Attiny85

  SpenceKonde/ATTinyCore#860 · Filter by author legalmachinery opened on May 24, 2024
  2