Problems upgrading MMU2 firmware to 3.0.2
I've just updated my Mk3S to firmware 3.14.0 without any trouble. However, I'm being less successful in upgrading the MMU2 to 3.0.2.
When I select Flash Printer Firmware from PrusaSlicer it correctly identifies the MMU2 but I cant select an image file. Oddly, if I select Advanced: Output log I can then choose the hex file and the Serial port is changed to Autodetected.
Clicking Flash however gives this error:
avrdude-slic3r: Version 6.3-20160220-prusa3d, compiled on Oct 18 2024 at 12:52:31
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2014 Joerg Wunsch
Using Port : /dev/ttyACM0
Using Programmer : avr109
Overriding Baud Rate : 57600
avrdude-slic3r: ser_open(): can't open device "/dev/ttyACM0": Permission denied
avrdude-slic3r: Could not open port: /dev/ttyACM0
Im running Manjaro Linux
I've added myself to the uucp group (which is the /dev/ttyACM0 group) and logged out and back in but it still fails.
I've tried giving read write access to /dev/ttyACM0 to everyone, no dice.
I've even tried adding the dialup group (because it doesn't exist) and adding myself to that but still no joy.
I'm out of ideas, can anyone help?
RE:
Well I resorted to my Windows machine and it successfully flashed the MMU to 3.0.2.
However, now the MMU isn't recognised at all. Support shows MMU N/A.
The MMU is alive as it goes through a startup sequence, LEDs 1-2 solid green, LED 4 slow flash orange, LED 5 rapid flash green and then all off except LED 4 green.
It looks like 3.0.2 has screwed it up. Can I revert to an earlier version?
RE: Problems upgrading MMU2 firmware to 3.0.2
Aha, it seems the MMU is disabled after this upgrade. You need to go into Settings and turn the MMU back on and also hit the ResetMMU before it gets recognised.
Panic over...
RE: Problems upgrading MMU2 firmware to 3.0.2
avrdude-slic3r: ser_open(): can't open device "/dev/ttyACM0": Permission denied
This is because it resets the MMU2 which causes the serial to disconnect and then reconnect. There is about 1/10th of a second (at least on mine) between initialization and the dbus rules kicking in during which it belongs strictly to root. Unfortunately the process spends no time waiting for the device to settle, it just tries to start writing the instant it reappears, but since it's a root device you get "Permission denied". I spent about an hour trying to dig through stuff trying to see if it was a script or something I could inject a 1 second sleep into, but gave up and just ran prusa-slicer as root. Not generally recommended but I was desperate by that point, and no Windows boxen to fall back on anymore. Hoping this advice helps other Linux users in the future, or leads to a proper solution and no "sudo" hacks.