Marlin 2.0.9 is a progressive release featuring a major overhaul of the motion system. The number of linear axes can now be configured, allowing anywhere from one linear axis (X only) up to a total of six (X, Y, Z, U, V, W). The names of the axes can also be customized to your liking (barring conflicts with other G-code parameters).

New Features

• ✨ TMC Driver distinct baudrates (#22008)
• 🏗️ Support for up to 6 linear axes (#19112, #22056, #22068, #22075, #22094, #22112)
• ✨ Add Laser Based I2C Ammeter Feature (#21835, #22079)
• ✨ More flexible redundant temp sensor (#22085)
• ✨ Single Extruder with Dual Stepper Drivers (#21403)
• ✨ Redundant Part Cooling Fan (#21888)

New Machines and Boards

• ✨ BigTreeTech Octopus V1.1 (#22042)

LCDs and Controllers

• 🌐 Update Slovak language (#22000)
• 📺 Fix and enhance FTDI EVE Touch UI (#22047)
• 🩹 Fallback ID for MKS TS35 V2.0 (#22031)
• 🎨 Reorganize FTDI Touch UI variants (#22066)
• 🎨 Fix and improve FTDI Eve Touch UI (#22093)
• 🌐 Update Hungarian language (#22083)
• 🐛 Fix ExtUI/DGUS Celsius display (#22121)
• 🐛 Include common TFT driver macros (#22125)
• 🎨 ExtUI "user click" and other tweaks (#22122)
• ✨ MULTI_VOLUME for Color UI and MarlinUI (#22004)

Optimized / Improved

• ♻️ Refactor Linear / Logical / Distinct Axes (#21953)
• ⚡️ Optimize Sensitive Pins array (except STM32) (#22080)
• ⚡️ Home Z (and maybe XY) at the start of G35 (#22060)

Fixed Boards / Pins

• 🎨 Reorganize BTT_E3_RRF_IDEX_BOARD (b99411b62b)
• 🎨 Clean up stops, sdss pins (dc202b3cb3)
• 🐛 Fix Creality v4 servo timer (#22021)
• 🔧 EEPROM options for BTT SKR 1.4 (#22092)
• 🐛 Fix boot / SD for STM32 (F103Rx) boards (#22087)
• 🔨 Robin Nano V3 overridable POWER_LOSS_PIN (#22123)
• 🔨 Fix Serial+MSC for _USB envs (#22116)
• 🔥 Remove Chitu default Touch Calibration (#22133)

Issues Fixed

• 👽️ Fix usb-host-msc-cdc-msc issue (#22025)
• 🐛 Fix Z endstop enum (72b9f84723)
• 🐛 Fix MMU compile with >5 EXTRUDERS (#22036)
• 🐛 Fix M140 print job timer autostart (#22046)
• ✨ Update G34 for 4x Z steppers (#22039)
• ♻️ Patches for Zero Extruders (with TMC) (82ea06e6a4)
• 🐛 Fix small/huge I2C EEPROM address (#22081)
• 🐛 Fix UBL 'R' parameter and adjust 'P' (#22129)
• 🚑️ Prevent BFT unaligned compressed data corruption (#22134)
• 🐛 Prevent stepper sleep during long UBL idle (#22137)

Configuration

• 🔧 Check G29_RETRY_AND_RECOVER requirements (#21921)
• 🔧 Expose hidden BLTOUCH setting changes (#22069)
• 🔧 Enforce BLTouch settings (#22086)
• 🐛 Use whole PROBE_TEMP_COMPENSATION values (#22130)

New HAL/STM32 Targets

• 🔨 Creality v4 with STM32 HAL (#21999)
• 🐛 Fix env:STM32F103RE maple/unified split-up (#22019)
• 🔨 MKS Robin E3 for HAL/STM32 (#21927)
• 📦️ STM32F103RE_btt(_USB) with HAL/STM32 (#22040)
• 📦️ Malyan M200 with HAL/STM32 (#22052)
• 👽️ Include <EEPROM.h> in STM32 (for now) (#22054)

Build / Upload

• 📌 Use U8glib-HAL@~0.4.5 (25053572ec)
• 🐛 Fix Probe Temp Calibration compile (#22032)
• 🔨 Move FLY_MINI env to stm32f1.ini (c207111cc6)
• 🔨 Consolidate BTT linker scripts (62dc3e7a22, #22038)
• 🐛 Fix STM3R / BEAST envs (#22028)
• 📌 Update FYSETC E4 to espressif32@2.1.0 (#22049)
• 🔨 MightyBoard envs for Auto Build Marlin (#22100)
• 🔨 Envs for BTT SKR Mini with RET6 (512K) (#22050)
• 🏗️ Refactor build encrypt / rename (#22124)

General Cleanup

• 📝 Update G61 comment (8f59d44e4d)
• ⚰️ Remove obsolete CUSTOM_SPI_PINS (#22058)
• 📝 Describe G12 XYZ (799a4ecab9)
• 🔨 Remove obsolete ON_BOARD_SPI_DEVICE (87344ae7f3)
• 🎨 Clean up LPC1768 SPI init (fd3f7b3473)
• 📝 Number SKR EXP headers (c221ee1144)
• 🩹 Use #pragma once in pins files (9bf5cddb46)
• 🎨 General cleanup of extui/dgus (d5510ea519)

For Developers

• 👷 Add caching to CI workflow (0e40d47c72)
• ⚗️ 32-bit float constants (STM32F1) (#21996)
• 🔧 Treat TPARA like SCARA in mfconfig (62a595750d)
• 🎨 Adjust some conditionals (0e1e159187)