Summary
- Wi-Fi auto-reconnect fixed
- Improved Wi-Fi (ESP) flashing
- RTC fixed
- Additional hotend protection
- UI fixes
- New error code URL
- Improved bootstrap
- Known issues
This is the final release of firmware 4.4.1. This changelog is a summary of the previous releases RC1 and RC2. 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.
Improved Wi-Fi (ESP) flashing
Previously, in some scenarios, flashing the Wi-Fi ESP module failed after the firmware was updated. In case the printer was restarted using the hardware button below the LCD, the ESP remained powered on and didn’t power cycle. It was necessary to turn off the printer completely and turn it on again.
The issue was found on the CPU pin shared with the RTC (real-time-clock) and in some random scenarios, it was impossible for the system to send a “reset” signal over this pin. Developers have fixed this problem and now the ESP reset should work correctly.
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
UI fixes
Overlapping buttons fixed
The dialogue for credentials creations sometimes showed part of the button from the previous screen.
Button displayed outside the screen
While trying to print G-codes sliced with a filament different than the one already loaded in the printer, the printer displayed one button partly outside the screen. This issue was affecting all languages except English.
New error code URL
Starting this release the error codes displayed on the screen will have a shorter URL, which is more convenient for the user.
- Old format: “help.prusa3d.com/errorcode” (e.g. “help.prusa3d.com/12201”)
- New format: “prusa.io/errorcode” (e.g. “prusa.io/12201”)
Note: all the current URLs based on the old format will be kept active.
Improved bootstrap
Developers made several optimizations and flashing the firmware is now faster. The overall process took previously around 3-4 minutes, now it takes just 20 seconds.
Known issues
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.