4.4.1-RC1 Firmware for Original Prusa MINI/MINI+  

4.4.1-RC1 Firmware for Original Prusa MINI/MINI+

Hello all; 
We are pleased to announce the release candidate for the next new firmware version for the Prusa MINI / MINI+ 

 Please note that this is a release candidate, so if you run into any issues, please use the link at the end of this article to report any issues. 

Summary

• Wi-Fi auto-reconnect fixed
• RTC fixed
• Additional hotend protection
• Improved bootstrap
• Known bugs

This is the first public release candidate of the upcoming firmware 4.4.1. The focus is on bug fixes related to ESP Wi-Fi and RTC.

ATTENTION: Before you rush flashing new firmware, please note that this time, there are two files needed on the USB flash drive. Both firmware and bootloader must be updated!

Wi-Fi auto-reconnect fixed

The auto-reconnect feature in some scenarios didn't work properly. For this release, the developers have updated the algorithm and once the ESP Wi-Fi module loses connection to the selected Wi-Fi network, it will try to reconnect after 60 seconds automatically.

RTC fixed

In order for the printer to remember the correct time, the RTC (Real Time Clock) was implemented. Users reported that this feature sometimes misbehaved and as a result, the printer displayed the incorrect time when the print will be finished. This is now fixed.

However, keep in mind that the timezone has to be set manually, otherwise the feature will not work.

Additional hotend protection

Similar to MK3S+ thermal model protection, also MINI/MINI+ is getting additional detection and protection against hotend overheating. The firmware is checking every second, whether the heater is working as expected. If the measured values differ by more than 30 % for longer than 40 seconds in a row, the printer immediately halts the heating and turns on the print fan at full speed to help cool down the print head.

An error message is displayed on the screen informing the user about what happened. Check whether the thermistor and heater are correctly inserted and tightened in the heater block. Then look for any damage to the wiring. Should you find any, stop using the printer and get a replacement.

Print can be resumed and the print fan is automatically restored to its original value. Please note that this feature is still in development and some changes are expected. Should there be any issues, please let us know using GitHub issues

Improved bootstrap

Developers made several optimizations and flashing the firmware is now faster.

Known bugs

ESP flashing failed

In some scenarios, flashing the ESP Wi-Fi might fail after the firmware is updated. In case the printer is restarted using the hardware button below the LCD, the ESP might remain powered on and doesn’t power cycle. Please turn off the printer completely and turn it on again. This behavior will be fixed in the upcoming releases.

First layer calibration without filament

While running the calibration of the first layer a random bug might occur if the user decides to start without the filament and load the filament in progress. Please reset the printer and load the filament first, then run the calibration.

Download Link:

github.com/prusa3d/Prusa-Firmware-Buddy/releases/tag/v4.4.1-RC1

How to flash the firmware on MINI:

Copy the firmware file (.bbf) onto the USB drive with FAT32 formatting Insert the flash drive in the MINI's USB port Turn the printer ON (or reboot it) A new screen will appear Confirm you want to flash the firmware

Please report any bug here:

github.com/prusa3d/Prusa-Firmware-Buddy/issues

As always, we wish you happy printing and look forward to your feedback!