1.0.6 Firmware for MMU2S

Summary:

• Improved stealth mode
• Unload speed decreased
• Disabled unwanted selector movement
• Automatic idler disengagement

Detailed description of changes:

Improved stealth mode

The value of the idler holding current was increased in order to ensure its proper motion. Low idler holding current value might lead to an idler misalignment. For MK3S MMU2S the idler holding current values are the same for Stealth and Normal mode. For MK2.5S MMU2S only stealth mode is available.

During acceleration and deceleration, the current value drops or increases. This is directly affecting the value of the torque, which might be low in some situations and thus the motor doesn't have enough "power" to load/unload the filament. To avoid this situation we are changing the value of constant in the Trinamic driver, which results in sufficient current and torque under any type of movement.

Similarly in Stealth mode, for some movements, the unit switches temporarily to the Normal mode, which provides higher current and torque. As soon as the torque is no longer needed, the mode is switched back to the Stealth.

Unload speed decreased

As explained in the paragraphs above, there were some scenarios, where the motors might not have enough torque to load/unload the filament properly. To avoid any issues, unload speed is slightly decreased to maintain a higher torque value.

Disabled unwanted selector movement (during fail state)

When the MMU2S experiences a filament load/unload fail, it asks the user to solve the issue. After resolving the problem, the user has to confirm it by pushing the right button on the unit. However, if the right button was pressed for a longer period, the unit also moved the selector to the next filament. The current release is changing this behavior and selector can be moved only after the right button is pressed again.

Automatic idler disengagement

During the filament load, the MMU2S unit is pushing the filament using the idler until getting information from the extruder (IR-sensor). This information was sometimes lost and the idler was still pushing even when no longer needed. In the current release as soon as the preset distance is loaded through the MMU2S unit, the idler automatically disengages and returns only when prompted by the extruder (IR-sensor).

Thanks to Brian Smith for contributing to the code, more information in Make sure idler disengages

1.0.6-RC2 Firmware for MMU2S

Summary:

• Improved stealth mode
• Unload speed decreased
• Filament cut feature
• Disabled unwanted selector movement
• Automatic idler disengagement

Detailed description of changes:

Improved stealth mode

The value of the idler holding current was increased in order to ensure its proper motion. Low idler holding current value might lead to an idler misalignment. For MK3S MMU2S the idler holding current values are the same for Stealth and Normal mode. For MK2.5S MMU2S only stealth mode is available.

During acceleration and deceleration, the current value drops or increases. This is directly affecting the value of the torque, which might be low in some situations and thus the motor doesn't have enough "power" to load/unload the filament. To avoid this situation we are changing the value of constant in the Trinamic driver, which results in sufficient current and torque under any type of movement.

Similarly in Stealth mode, for some movements, the unit switches temporarily to the Normal mode, which provides higher current and torque. As soon as the torque is no longer needed, the mode is switched back to the Stealth.

Unload speed decreased

As explained in the paragraphs above, there were some scenarios, where the motors might not have enough torque to load/unload the filament properly. To avoid any issues, unload speed is slightly decreased to maintain a higher torque value.

Filament cut feature

This feature will be utilizing the included blade to cut the unwanted tips of the filament. The current release contains improvement in the situation when the printer recognizes a failed cut. After the filament is cut, printer tries to load the filament and trigger the F.I.N.D.A. sensor in the MMU2S unit, in case this operation fails, all movable parts of the MMU2S unit are rehomed to ensure proper alignment.

The filament cut feature is disabled for now, we are still working on it. We plan to enable it in a future firmware release.

Disabled unwanted selector movement (during fail state)

When the MMU2S experiences a filament load/unload fail, it asks the user to solve the issue. After resolving the problem, the user has to confirm it by pushing the right button on the unit. However, if the right button was pressed for a longer period, the unit also moved the selector to the next filament. The current release is changing this behavior and selector can be moved only after the right button is pressed again.

Automatic idler disengagement

During the filament load, the MMU2S unit is pushing the filament using the idler until getting information from the extruder (IR-sensor). This information was sometimes lost and the idler was still pushing even when no longer needed. In the current release as soon as the preset distance is loaded through the MMU2S unit, the idler automatically disengages and returns only when prompted by the extruder (IR-sensor).

Thanks to Brian Smith for contributing to the code, more information in Make sure idler disengages

1.0.5 Firmware for MMU2

This fw version improves mmu2 unit function when used with MK3S and MK2.5S printers with IR sensor. Especially T-code filament loading phase reliability was improved. It is now possible to resume print after MMU load fail detected by printer also by MMU button.

1.0.4 Firmware for MMU2

Description of changes compared to 1.0.4-RC1:

MK2.5 + MMU homing hotfix:

Selector position after homing is now more accurate on MK2.5+MMU2 setup.

Drive error detection improved:

False drive error could sometimes appear after powering-up printer. This has been fixed.

1.0.4-RC1 Firmware for MMU2

Summary:

• Drive error detection and counter
• Undesired unload fixed
• Improved eject

Detailed description of changes:

Drive error detection and counter:

MMU2 unit can now deal with a state where Trinamic drivers were not able to provide enough power for steppers. A possible cause can be broken MMU2 power supply wiring, connectors etc. If this state is detected the MMU2 unit rehomes and automatically continues printing. If the problem occurs three times in a row, the MMU2 unit stops printing and starts flashing continuously with red and green LEDs. Also, MMU2 unit stores information about all drive errors into its memory and the total number of drive errors can be shown in the menu "Fail Stats MMU -> Total" as item "MMU power fails" (printer FW 3.5.2-RC1 and higher).

Undesired unload fixed:

There was a scenario where MMU2 unloaded filament out of Bondtech gears instead of parking it to the default position. This state needed user intervention. This bug has been fixed in the current FW version.

Improved eject:

The filament is now retracted when recovering from eject, so it doesn't get broken if the user forgets to remove it.

1.0.3 Firmware for MMU2

This is final version 1.0.3 firmware. This firmware version contains following features:

• Power panic support
• Smarter operation
• Faster Individual Filament Calibration

Detailed description of these features can be found in 1.0.3-RC1 change log.
There is no difference between current 1.0.3 firmware version and previous 1.0.3-RC1 version.

1.0.3-RC1 Firmware for MMU2

Power panic support

This firmware version ensures that power panic works correctly on MK3 printers with MMU2. In case of a power surge, the printer will save the latest G-code instructions and after the power is restored, rehomes and continues with the print.

Smarter operation

In the previous firmware versions, when the filament was loaded to the extruder during a power-on (e.g. resetting the printer), the user had to manually remove the filament first. Otherwise, the MMU2 unit was unable to finish the initializing sequence. Starting this firmware release, the unit finishes the sequence with filament loaded and when there is a need to move with the selector (e.g. a user wants to use another filament slot), the printer indicates with all LEDs flashing red to unload the filament first or in case of resuming the print after a power failure, the printer unloads the filament by itself.

Faster Individual Filament Calibration

Now, there is a possibility to speed up the movement of pulleys while adjusting the filament position during the PTFE length calibration by pressing the left/right button for a longer period of time. Also, the maximum value of the PTFE tubing length was increased. These two changes should help users with custom modifications (such as using the MMU2 inside an enclosure with longer PTFE tubing).

1.0.2 Firmware for MMU2

This firmware version is specifically for users who use MK2.5 + MMU2 setup. If you use MMU2 with MK3 printer there is no need to upgrade MMU2 firmware to this version.
In previous firmware versions, the MMU2 operation was quite loud when using with MK2.5 printer. This firmware solves the issue. When using the MK2.5 printer with firmware 3.4.2 and higher, the printer sends command for setting MMU2 currents specifically for usage with MK2.5 and switches MMU2 drivers to stealth mode.

1.0.1 Firmware for MMU2

Summary:

• pulley size calibration
• mmu2 factory reset (possibility to erase EEPROM memory)

Detailed description of changes:

Pulley size calibration:

MMU2 pulleys diameter can vary because of manufacturing tolerances. This can lead to issues when loading filament from MMU2 to extruder bondtech gears. MMU2 firmware now contains pulley size calibraiton for each pulley independently.