Stock Prusa MK3s+ Einsy Klipper Fix
Added 2021-02-25 23:57:08 +0000 UTCI've been working like a madman to get a Klipper build to work correctly and at speed for about 2 days now. I have the firmware ready but there was a new hurdle... the Einsy USB is slow as heck.
To sum it up when you get an Einsy from Prusa, so basically any time you buy a MK3s, the USB serial is setup in a way that it handles USB to serial issues incorrectly by not being able to process the data load and throwing errors. Ever had issues with Octoprint and your prusa trying to print fast? Bingo.
Sadly this translated to Klipper since it sends all it's data over USB and would cause an MCU error, MCU 'mcu' shutdown, and basically stall klipper and kill the printer connection.
Why? With the way the Einsy is setup from Prusa the USB serial interface can fill up faster due to a coded smaller well that when it fills up just sends errors. "I'm full no more data please." When that happens for 1-5 seconds Klipper shuts down because it triggers as a usb disconnect and now you have a dead connection between pi and printer.
So are we screwed??? NOPE!
In comes the community and we have a fix for it but it's not setup for someone like me who is a noob with coding, pi's, linux, programmers, arduino and so on. Without help since nobody seemed to want to help I pushed through and was able to figure it out and make it work on the first try! For that you all get the fix using the what I find to be the easiest method possible.
What do you need? Spend a few bucks and get one of these USD asp programmers
You'll also need a pi with octoprint or similar linux based OS installed as well as a method to get into the pi. I used Putty on my windows PC and SSH'd into that bad boy to do the work.
BEFORE YOU BEGIN POWER DOWN THE PRINTER and THE PI.
Step 1: Connect the USPasp to the Pi via nay of the open USB ports
Step 2: Connect the USPasp to the einsy via the 6 pin connection pictured below
Step 3: Connect the Pi to power. YOU DO NOT NEED TO POWER THE EINSY and should look like the image below
Step 4: SSH into your pi. I used Putty but use what you love and login
Step 5: Install AVRdude on your pi using THIS GUIDE
Step 6ish: We are going to use a modified version of THIS GUIDE to reprogram the serial USB so use it as a reference and nothing more.
Step 7: sudo avrdude -p m32u2 -F -P usb -c usbasp-clone -U flash:r:firmware_backup.hex:i -U eeprom:r:eeprom.hex:i -U lfuse:r:lowfuse:h -U hfuse:r:highfuse:h -U efuse:r:exfuse:h -U lock:r:lockfuse:h
Step 8: sudo avrdude -p m32u2 -F -P usb -c usbasp-clone -U hfuse:w:0xD1:m
Step 10: sudo avrdude -p m32u2 -F -P usb -c usbasp-clone -U flash:w:DFU-hoodserial-combined-PrusaMK3-32u2.hex -U lfuse:w:0xFF:m -U hfuse:w:0xD9:m -U efuse:w:0xF4:m
And Bob's your uncle!!!!!
