BIGTREETECH TMC2226 V1.0 StepStick Driver – UART, StealthChop2 and StallGuard4

The BIGTREETECH TMC2226 V1.0 is a StepStick driver for two-phase bipolar stepper motors, designed to combine quiet motion, accurate control and advanced configuration in 3D printers, light CNC machines, robots and automation projects. It can operate through standard STEP/DIR signals or communicate over UART so firmware can configure current, microsteps, operating mode and diagnostics.

This listing is specifically for revision V1.0. It includes one driver, one blue heatsink and one UART connection cable. The TMC2226 shares its firmware integration with the TMC2209, but its standalone microstep table, sense resistance, VREF procedure and cooling requirements must still be checked separately.

Main features

• StealthChop2: particularly quiet and smooth motion at suitable speeds and loads.
• SpreadCycle: current control intended for greater dynamics, speed and torque margin.
• MicroPlyer: internal interpolation up to 256 microsteps for smoother motion without requiring that pulse rate from the controller.
• StallGuard4: load estimation and stall detection, suitable for sensorless homing when the controller, DIAG routing, firmware and mechanics are compatible.
• CoolStep: load-adaptive current when configured by compatible firmware; it is not automatically active in every installation.
• Single-wire UART: firmware configuration of RMS current, microsteps, operating modes and diagnostics.

Technical specifications

Compatibility depends on the installed controller

It may be used conditionally on controller boards with replaceable StepStick sockets that support the TMC2226 pinout, orientation, voltages and operating mode. UART additionally requires suitable PDN_UART routing, jumpers and address selection; sensorless homing also requires DIAG to reach the correct endstop input.

The BIGTREETECH SKR 3 and BIGTREETECH Octopus Pro H723 provide replaceable sockets and UART configuration, but each board has its own jumper and pin scheme. Physical fit alone does not establish electrical compatibility.

It is not a direct replacement for boards with soldered drivers, proprietary connectors or a different pin assignment. Compatibility must not be assumed from the printer name alone: a Voron, Creality, Prusa or another machine may contain different controllers and revisions.

If you prefer the more widely used module with controller-specific documentation across many boards, see the BIGTREETECH TMC2209 V1.3. Both share UART integration, but should not be exchanged without checking configuration and limits.

Standalone STEP/DIR or UART configuration

Standalone STEP/DIR mode

The controller drives EN, STEP and DIR without accessing the TMC2226 registers. Microsteps depend on MS1/MS2 and current is adjusted through VREF. This supports controllers without UART, but firmware current adjustment, advanced diagnostics and full StallGuard4 integration are not available.

UART mode

UART allows firmware to configure RMS current, microsteps, interpolation, idle current reduction, StealthChop2, SpreadCycle and diagnostics. BIGTREETECH specifies that the TMC2226 uses TMC2209 UART integration; the controller pins and jumpers still need to be configured correctly.

Standalone microstep table

This table is specific to the TMC2226. Do not copy the standalone table of a TMC2208 or TMC2209. In UART mode, MS1/MS2 may also select the driver address while firmware controls the microstep resolution.

V1.0 pinout

Safe installation

1. Disconnect the power supply and USB cable.
2. Read the pinout and jumper diagram for the exact controller revision.
3. Verify orientation using VM/GND and EN/DIR before inserting the driver.
4. Configure the socket for UART or standalone STEP/DIR according to that controller manual.
5. Identify the two motor coils and connect them as A and B pairs.
6. Fit the heatsink on the intended thermal area without touching pins or the potentiometer, and provide active airflow.
7. Configure a cautious initial current and test short, slow moves.
8. Check communication, temperature, noise, torque and skipped steps before increasing performance.

Never connect or disconnect the motor, insert or remove the driver, or change jumpers while the electronics are powered.

Current adjustment and cooling

Insufficient current can cause skipped steps; excessive current increases motor and driver temperature and may trigger thermal protection. In UART mode, configure RMS current from the motor specification and verify the result under actual load. In standalone mode, use the VREF procedure for this revision: there is no universal voltage that applies to every TMC module.

The photographed revision uses sense resistors marked R150, corresponding to 0.150 Ω. Check this marking on your own unit before entering a sense resistance in firmware because future revisions may use different components.

Marlin configuration

Marlin explicitly instructs users to select the TMC2209 driver type for a TMC2226. For UART, declare each required axis in Configuration.h:

#define X_DRIVER_TYPE TMC2209

TMC2209_STANDALONE may be appropriate for standalone operation without UART. The TMC sections in Configuration_adv.h must be reviewed for RMS current, microsteps, interpolation, quiet mode, monitoring and sensorless homing when used. UART and DIAG pins must come from the pin file and manual for the actual controller.

• M122: checks communication and displays driver status.
• M906: reads or changes current in mA when UART is operating.
• M913: changes the hybrid threshold when HYBRID_THRESHOLD is enabled.
• M914: adjusts sensitivity when SENSORLESS_HOMING is enabled.

Selecting TMC2209 does not automatically configure current, StealthChop, SpreadCycle or StallGuard4. Verify communication first and then tune each function on the actual machine.

Klipper configuration

Klipper uses the compatible [tmc2209 ...] section; there is no separate [tmc2226 ...] section. Complete this structure with the actual pin and motor current:

[tmc2209 stepper_x]
uart_pin: <controller_UART_pin>
run_current: <suitable_RMS_current>
sense_resistor: 0.150
interpolate: True
stealthchop_threshold: 0

run_current is expressed in RMS amperes and has no universal value. The 0.150 value corresponds to the R150 shunts visible on this photographed V1.0 and must be physically verified. stealthchop_threshold: 0 retains SpreadCycle; if StealthChop is required, select a threshold after evaluating noise, torque and accuracy. DUMP_TMC STEPPER=stepper_x helps verify UART communication and registers.

Sensorless homing in Klipper

[tmc2209 stepper_x]
diag_pin: ^<controller_DIAG_pin>
driver_SGTHRS: <calibrated_value>

[stepper_x]
endstop_pin: tmc2209_stepper_x:virtual_endstop
homing_retract_dist: 0

Correct sensitivity depends on current, homing speed, moving mass, temperature and friction. It must be carefully calibrated on the real axis; do not copy another printer's value. A physical endstop may remain the safer choice on critical axes or mechanisms where a missed detection could cause damage.

Is it right for you?

It is right for you if

• Your controller has a compatible replaceable socket and you have checked pinout, orientation and jumpers.
• You want quiet motion with UART configuration and optional StallGuard4.
• You can adjust current for your motor and provide active cooling.
• You will configure Marlin or Klipper as TMC2209 using the controller documentation.

It is not right for you if

• Your controller has soldered drivers or a proprietary connector.
• You need a plug-and-play replacement without checking revision, jumpers, firmware or current.
• You intend to use maximum current without a heatsink, airflow and thermal test.
• You expect automatic sensorless homing without routing DIAG and calibrating the mechanics.

Contents

• 1 × BIGTREETECH TMC2226 V1.0 driver.
• 1 × blue heatsink.
• 1 × UART cable.

The BIGTREETECH TMC2226 V1.0 is a capable and quiet option for controllers with replaceable driver sockets. Reliable operation depends on checking electrical compatibility, using its own microstep table, configuring UART and current correctly, and maintaining sufficient cooling.