2026q3 release

This release covers everything from 2026-07-01 and has been tested with avr-gcc
v14.2.0 from upstream and arm-none-eabi-gcc v14.2.1 from xpack.

Breaking changes:

modm::math::crc8_ccitt discarded the MSB of every input byte on non-AVR
targets and now computes the correct CRC. This changes the AMNB header CRCs on
the wire, so AMNB nodes must be updated together.

Features:

• RP2040 PIO driver with compile-time assembler.
• RP2040 flash driver.
• STM32H7 flash driver with single and dual bank support.
• CMSIS-DAPv2 integration to turn any USB-capable board into a debug probe.
• CRC-8/Maxim implementation.

Integrated Projects:

• CMSIS-DAP added at v2.1.2.

Fixes:

• Fix PSPLIM triggering during fiber context switch on ARMv8-M.
• 32-bit timer counter size for TIM2 and TIM5 on STM32H5.
• Compilation of STM32 GPIO module with GCC15.
• Flash memory detection for aliased and banked flash on Cortex-M.
• Windows compatibility of TinyUSB descriptors.

New device drivers:

• LTC2497 ADC as modm:driver:ltc2497.
• LTC2499 ADC as modm:driver:ltc2499.
• MCP23008/MCP23S08 IO expander as modm:driver:mcp23x08.
• PCAL6524 IO expander as modm:driver:pcal6524.
• MAX14661 analog multiplexer as modm:driver:max14661.
• MC33XS2410 power switch as modm:driver:mc33xs2410.
• AT21CSx1 single-wire EEPROM as modm:driver:at21csx1.

Known bugs:

• OpenOCD cannot enable SWO on STM32H7 targets. See #1079.
• arm-none-eabi-gdb TUI and GDBGUI interfaces are not supported on Windows.
  See #591.
• Generating modm on Windows creates paths with \ that are not compatible with
  Unix. See #310.
• lbuild build and lbuild clean do not remove all previously generated files
  when the configuration changes. See #285.

Many thanks to all our contributors:

• Andrey Kunitsyn (@andryblack)
• Christopher Durand (@chris-durand)
• Henrik Hose (@hshose)
• Matthias Schuller (@maschull106) 🎉
• Niklas Hauser (@salkinium)
• TudorFanaru18 (@TudorFanaru18) 🎉

PR #1383 -> 2026q3.

Detailed changelog

2026-09-20: Add AT21CSx1 EEPROM and MC33XS2410 power switch drivers

PR #1378 -> 434ca5c.
Tested in hardware by @salkinium.

2026-08-07: Add ADC, IO expander and analog MUX drivers

PR #1372 -> 3db0a3d.
Tested in hardware by @salkinium.

2026-07-14: Add STM32H7 flash driver

PR #1345 -> cb9cff4.
Tested in hardware by @hshose.

2026-07-12: Add CMSIS-DAPv2 integration

PR #1360 -> 42ae970.
Tested in hardware by @salkinium.

2026-07-05: Add RP2040 flash driver

PR #1362 -> 4d55600.
Tested in hardware by @andryblack.

2026-07-04: Add RP2040 PIO driver with compile-time assembler

PR #1358 -> a50e1cc.
Tested in hardware by @andryblack.