Snake Mini

Wanted

FW developer, testers, and graphic designers are welcome.

Unofficial Firmware for the Prusa Mini and Mini+

Alternative FW for the Prusa Mini. There’s quite few improvements:

1. Hotend fan speed: Adds a menu option to unlock the hotend fan speed and increase it from the Prusa Firmware’s default 38% to anywhere from 50-100%.
2. Skew compensation: Turns on skew compensation in Marlin and allows it to be configured with M852.
3. OctoPrint screen: Adds support for M73 (print progress) and M117 (LCD messages).
4. PID tuning: Read nozzle and bed PID parameters and tune them automatically.
5. Max Temps: Raises the maximum bed temperature from 100C to 110C and nozzle temperature from 275C to 285C (use with caution!).
6. Settings during print: You can change Snake settings, Control and Settings during printing.
7. Faster nozzle cooling: If you wait for nozzle cooling before MBL, you can call M109 R170 C which uses print fan to speed up cooling.
8. Game: Instead of printing you can enjoy simple game.
9. Bigger time: Printing and remaining time is now bigger.
10. Selftest check: Now you can select Ignore to immediately pass all selftests.
11. Temperature calibration: You can calibrate PID temperature control for your hotend/bed directly from the menu. Calibration does 5 cycles.
12. Total time: Elapsed, Remaining and Total or End time are shown during printing. 13.
13. Adjust brightness: You can change brightness of the display. It does not dim the light but draws darker colors.
14. Cold mode (min.temp.): If you enable Cold Mode, temperatures (once set) won’t drop below 30°C. For safety reasons cold mode must be enabled after every start of the printer.
15. Show MBL and tilt: After mesh bed leveling (G29) you can go to Snake Settings and see the MBL Z levels at the measured points and check the tilt of the axes. Levels are shifted to avoid negative numbers.
16. Speed up: Parking, unparking and other moves are done faster.
17. Different printers: Next to a standard version, other versions are released:
    1. coreXY
    2. i3 MK3.3 (i3 MK3 with MINI board, MINI display, Z motor split, and mosfet on heating)
    3. i3 MK3.5 coreXY
18. Different languages
19. Avoid display flashing: Some displays flash with original FW.
20. High geared extruder: Allow up to 2000 steps/mm for extruder.
21. Adjustable axes:
    1. length (includes long bed HW)
    2. steps/mm
    3. direction
    4. current
    5. stealth / strong mode (StealthChop / SpreadCycle)
    6. max. feedrate (for X and Y only)
22. Adjustable filament load length: Different extruders need different load length.
23. Adjustable homing sensitivity: X and Y homing sensitivity can be changed in menu and saved.

Feed the Snake

This FW is developed in spare time. If you like it, please consider supporting further development and updates by becoming a patron.

Installing

Jailbreak your Mini

You will need to cut out Prusa’s appendix to install custom firmware. Follow the instructions here. This is irreversible and voids the warranty, although in the US you are protected by the Magnuson-Moss Warranty Act.

Of course you could always buy a second Buddy board and run it on that one.

Alternatively, if you are good at very fine pitch soldering, you could lift the BOOT0 pin off the board entirely and make your own jumpers to connect it directly to 3.3V or GND as you need (the appendix merely shorts BOOT0 directly to GND).

Once you have done that, you can live and let live-stock.

Flashing

Whenever you install new firmware, it’s good practice to make a note of your settings first, particularly your Live Z Offset and your skew coefficients. Not all FW changes keep settings saved.

Download the latest release here. Copy the .bbf file to the root of your USB flash drive. Follow the instructions here to install the firmware. The bootloader will warn you the signature is incorrect - select “Ignore”.

First Run

If you lose your Prusa EEPROM settings during the upgrade process, when you first run the firmware, Prusa will send you to the initial calibration wizard. This can be a problem if you need to set custom e-steps before printing anything. Just skip the initial setup wizard, use the Snake Settings menu to configure your e-steps, and then rerun the setup wizard manually.

Livestock to Stock

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