Firmware 3.8.0-RC2 for Original Prusa i3 MK2.5S & MK2.5

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Jakub Dolezal

(@jakub-dolezal)

Member Admin

Firmware 3.8.0-RC2 for Original Prusa i3 MK2.5S & MK2.5

Hi guys,

a new release candidate is out! Note that this is still a testing version for experienced users 😉

What is new?

Power panic fix
Heatbed noise at 110 V (60 Hz)
Crash detection fixes
Addition of the ASA material

A detailed description of changes:

Power panic fix

In the previous release (RC1), the power panic function was broken and didn't work properly. This issue was caused by a new feature (still in development), which further lowers the noise made by the printer. Now, the code is fixed and power panic works as expected.

Heatbed noise at 110 V (60 Hz)

There were several reports regarding noise from the heatbed when the printer was connected to a 110 V (60 Hz) network. In the current release, the rising and falling edges of the pulse-width modulation (PWM) are adjusted to fix the unwanted noise. Previously, the PWM was falling from 30 Hz to 15 Hz and as a result, the PSU started to switch between high and low power mode, which caused the "clicking". Also, while printing at extremely high speeds over a USB connection, the altered PWM affected the planner, resulting in a slower print. This is now fixed as well.

Crash detection fixes

The crash detection feature can be turned off in the printer's menu, however, in the RC1 release, it stopped working for the Normal mode. Even when set to [OFF], the printer still detected the crash (issue #2094). The part responsible for crash detection was revised and fixed.

In very rare cases, prior to the printing phase, a false crash was detected and then while printing the first layer the printer skipped some longer segments of the G-code (above 30 mm). As a result, the extruder moved according to the next G-code instruction. We've adjusted the behaviour of the crash detection for the first layer, which solved this issue.

Addition of the ASA material

ASA is newly introduced to the Original Prusa i3 printers and can be considered a true successor to ABS. Starting this release, ASA is included in the preheat menu with support in the PrusaSlicer. The ASA option is missing in the "Load filament" menu and will be added in the next release. Learn more about ASA in our latest article ASA Prusament is here!

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