Disk init fail

[elhajj33]

Printer is a flashforge foto 8.9
Rpi is a Zero 2w

I can communicate with the printer over serials and I can see the files in the resin directory. See below:
/dev/loop0 4.0G 16M 4.0G 1% /home/pi/.octoprint/uploads/resin

However, i get his error whenever i try to print:

Send: M23 Xp_2.2s.fdg
Recv: //Disk init fail!
Recv: //Disk init fail!
Recv: //############sd_mounted Error! cann't open file !
Recv: ok N:964
Send: M4000
Recv: ok B:163/0 E1:159/0 E2:158/0 X:0.000 Y:0.000 Z:0.000 F:0/256 D:0/0/0 T:0
Repl: ok T:0 /0 B:163 /0
E1:159/0 E2:158/0 X:0.000 Y:0.000 Z:0.000 F:0/256 D:0/0/0 T:0

I'm not sure what the issue is. I see the files in octoprint and in the directory when I ssh....

[rudetrooper]

The printer isn't mounting the USB mass storage device for some reason. Did you properly connect the micro USB cable to from the USB-OTG port on the pi to the printers USB port?

[zeroecho]

Is USB-data cable likely the cause for all disk init errors @rudetrooper ? Tried 2, one with 5v taped and another with red wire cut

Here's what I see in terminal after connecting:

Repl: ok CBD make it.Date:Sep 9 2020 Time:10:56:30
-> ok FIRMWARE_NAME:CBD made it PROTOCOL_VERSION:V4.3.13_LCDC
Date:Sep 9 2020 Time:10:56:30

Send: M21
Recv: //Disk init fail!
Recv: ok N:2
Send: M20
Recv: Begin file list
Recv: //Disk init fail!
Recv: //Disk init fail!
Recv: End file list
Recv: wait
Repl: wait -> echo:busy processing
Recv: ok L:0
Send: M4000

[crimsonclyde]

Hi,

I end up with nearly the same, or exactly the same, what @elhajj33 and @zeroech posted.

Recv: //Disk init fail!
Recv: //Disk init fail!
Recv: //############sd_mounted Error! can't open file !

Hardware / Software Info

PI = Raspberry Pi 4 Model B Rev 1.2p
Printer: FIRMWARE_NAME:CBD made it PROTOCOL_VERSION:V4.3.13_LCDC (Mars2Pro)

Description

I checked /etc/fstab and had the entry to piusb.bin twice, maybe that was my fault. I changed it, rebooted, but same. sudo mount -a seems to work fine. No error.
Tried 2 different cables and bought even an OTG adapter for the PI (https://www.8086.net/products/#80860015). Same problem. I can move Z Axis (controlled via GPIO) and Octoprint works so far just fine.

Update (got it)

OK, I messed it up. The adapter I use mentioned in the description above is wrong. The PI 4B has only one OTG port, which is, the USB-C port. Luckily, I bought the USB-C OTG Adapter as well. https://www.8086.net/products/#80860017.

How to use it:
The adapter has three USB-C ports
1= Power -> Plugin your power supply which you normally use to power ur Pi
2= Data/Power -> USB-C to USB-C goes from this port into the PI
3= Data -> This is the connection between the splitter and the printer

I had to swap the Data cable since one did not work properly it tells me always "File is empty" but the file is there and accessible. I was able to see the file on the machine directly and if I hit print the print starts but not via Octoprint. So I just changed it to another one and it works now!
You may ask why not simply use a Pi Zero 2W? Well, hard to get one nowadays :) and this was the cheapest solution to my problem. No soldering, no power the PI via GPIO.

Awesome @rudetrooper !
Really this is great stuff!