Issues

• SAMD51 crystalless boards never enable USB clock recovery for DFLL48M

  bug
  adafruit/ArduinoCore-samd#403 · Filter by author hathach opened on Nov 5, 2026

• Grand Central M4: D9 (PB02) has wrong EXTERNAL_INT in variant.cpp — attachInterrupt(9) never fires

  adafruit/ArduinoCore-samd#394 · Filter by author Mr-Champagne-TCM opened on Jul 28, 2026

• analog_read() sampling rate is much slower than wiring.c thinks it is

  adafruit/ArduinoCore-samd#387 · Filter by author mzero opened on May 10, 2026
  1

• Integrated support for DMA into SERCOM for SPI/UART/Wire

  adafruit/ArduinoCore-samd#382 · Filter by author crabel99 opened on Jan 27, 2026
  1

• PlatformIO does not choose newer Adafruit TinyUSB

  adafruit/ArduinoCore-samd#379 · Filter by author DaAwesomeP opened on Nov 5, 2025

• SPI on Adafruit Metro M0 Express

  adafruit/ArduinoCore-samd#357 · Filter by author nerdyscout opened on Apr 22, 2024

• SAMD51(J19) revision F DMA issues with 2 identical TCCx trigger source

  adafruit/ArduinoCore-samd#356 · Filter by author flety-emmanuel opened on Mar 18, 2024
  1

• Feather M4 Express no PWM out on RX (0) or TX (1)

  adafruit/ArduinoCore-samd#349 · Filter by author caternuson opened on Aug 4, 2023
  1

• analogRead() freezing on several Trinkey boards

  adafruit/ArduinoCore-samd#343 · Filter by author caternuson opened on May 18, 2023

• Reading Analog Inputs with 12-bit resolution not working on SAMD51

  adafruit/ArduinoCore-samd#342 · Filter by author DevonReynolds opened on Mar 24, 2023

• UART SERCOM ref clock seems to be Main 120MHz, not SERCOM_FREQ_REF = 48MHz

  adafruit/ArduinoCore-samd#341 · Filter by author SimonMerrett opened on Mar 22, 2023
  1

• SPI DMA write-only transfer(txBuf, nullptr, count) corrupts following receives.

  adafruit/ArduinoCore-samd#335 · Filter by author greiman opened on Aug 15, 2022

• Actual SPI speed can be higher than maxSpeed requested in SPISettings

  adafruit/ArduinoCore-samd#334 · Filter by author greiman opened on Aug 14, 2022
  1

• QTPy_M0 variant has LED_BUILTIN but there is none

  adafruit/ArduinoCore-samd#327 · Filter by author jerryneedell opened on Mar 20, 2022
  2

• analogWrite on Atmel SAMD behaves differently than described by official Arduino documentation

  adafruit/ArduinoCore-samd#304 · Filter by author pauljurczak opened on Jun 27, 2021
  3

• Arduino Board Manager: "Warning: non trusted contribution"

  adafruit/ArduinoCore-samd#294 · Filter by author timonsku opened on Apr 20, 2021
  2

• Grand Central M4 MOSI and SCLK Pins Swapped

  adafruit/ArduinoCore-samd#284 · Filter by author Rymar-Eng opened on Mar 3, 2021

• SERCOM::initSPI() Prevents Hardware Control of SPI SS Signal by Clearing SERCOM_SPI_CTRLB_MSSEN

  adafruit/ArduinoCore-samd#283 · Filter by author Rymar-Eng opened on Feb 27, 2021
  3

• Bug: write-only SPI.cpp DMA transfers are not working

  adafruit/ArduinoCore-samd#280 · Filter by author RudolphRiedel opened on Dec 29, 2020

• Bug: Internal Compiler Error

  adafruit/ArduinoCore-samd#271 · Filter by author arock093 opened on Nov 5, 2020
  3

• PINS_COUNT is useless and inconsistent.

  adafruit/ArduinoCore-samd#268 · Filter by author WestfW opened on Oct 22, 2020
  4

• variant.cpp Feather M4 points to PA27 for USB DP (D+) pin

  adafruit/ArduinoCore-samd#260 · Filter by author wa1tnr opened on Aug 31, 2020
  1

• analogWriteResolution() issues

  adafruit/ArduinoCore-samd#256 · Filter by author mzero opened on Aug 19, 2020
  2

• SAMD21 still using the analogRead with the ADC bug (not waiting for the first convertion to finish) :(

  adafruit/ArduinoCore-samd#254 · Filter by author ricardodeazambuja opened on Aug 14, 2020

• Build warnings -- [-Wignored-qualifiers]

  adafruit/ArduinoCore-samd#252 · Filter by author henrygab opened on Aug 14, 2020