Karl_Williams
Posts: 61
Joined: Wed Mar 13, 2013 1:26 pm
Contact: Website

Version 2.1.1 M104 sent from SD card display problem

Sat Aug 02, 2014 12:33 pm

When an M104 command is sent from the SD card it doesn't turn on or off the led graphic beside the extruder in the machine control panel. Note that this doesn't affect the real leds on the viki LCD panel. I noticed this because I manually turn on the heated bed and extruder before a print to get them up to temp and when the print was finished, the extruder was turned off but the led graphic beside the extruder was still in the 'on' state. If the M104 command is sent from the communication window command line or if it is sent via USB then the led graphic works as it should.

I created 2 small files to test this:

on.g:
M140 S70
M104 S190 T0

off.g:
M140 S0
M104 S0 T0

Try running the files from USB and you will see that it works properly but if you put them on the SD card and run them from there you will see the problem.

dalew8abz
Posts: 120
Joined: Mon Mar 25, 2013 12:14 am
Location: Cleveland Heights, Ohio USA (4 mi. from MakerGear HQ!)
Contact: Website

Re: Version 2.1.1 M104 sent from SD card display problem

Sat Aug 02, 2014 4:50 pm

Karl,

When G-codes are sent from the SD card, they are NOT "echoed" up the USB port for S3D to see them and react. S3D has NO idea what gets sent from the SD card to the printer firmware. All it know is that the file was sent.

This is part of the attraction of printing from the SD card: S3D doesn't have to be there listening, and there's no potential "clogging" of the serial connection between the printer and S3D over USB to slow down the stream of data from the SD card to the firmware. You can yank the cable and take your PC and walk away and go to something else.

Also, some G code files have huge numbers of very small moves tied together (especially when printing lots of small-radius arcs and such), and the USB link can become a bottleneck, resulting in pauses at the printer and ruining the print. Printing from the SD card takes S3D and the USB link out of the chain so they CAN'T be a bottleneck. The firmware can read from the SD Card much faster than it can receive data over USB at 115.2 kbps, or even 230.4 or 250 kbps. Even using the SPI interface to the SD card and not the native 4-bit=wide SDC interface, it's way faster.

So S3D has no clue that the SD card turned the heat on or off and has no information sent to it upon which to base a decision whether the "LED" graphic should be shown "lit" or "dark".

It is polling for the temperatures to display on the temperature trend chart, so you could kind of "guess" from the temperature data, I suppose. But there's no indication of "ON" or "OFF" sent to S3D when printing from SD card.

Dale

Karl_Williams
Posts: 61
Joined: Wed Mar 13, 2013 1:26 pm
Contact: Website

Re: Version 2.1.1 M104 sent from SD card display problem

Sat Aug 02, 2014 5:19 pm

In my case I'm running the "print from SD card" from the control panel window. This used to work on the last version and it still works for the heated bed so I think that if the USB is connected then it does send that status back to the control panel. There is definitely still communication going on through the USB port while it is printing from SD because it updates the temperature graph. Like I said, this worked in the previous version so I'm thinking it's a bug.
Last edited by Karl_Williams on Sun Aug 03, 2014 11:26 am, edited 1 time in total.

Karl_Williams
Posts: 61
Joined: Wed Mar 13, 2013 1:26 pm
Contact: Website

Re: Version 2.1.1 M104 sent from SD card display problem

Sat Aug 02, 2014 5:25 pm

To prove my claim, create 2 files in a text editor:

on.g

M140 S70
M104 S190 T0

off.g
M140 S0
M104 S0 T0

Copy them to the SD card and then initiate "print from SD card" from the control window and choose on.g. You will see that that "on" status is relayed to the GUI led for the heated bed but not the extruder.
Now initiate "print from SD card" from the control window and choose off.g. You will see that the GUI led for the heated bed turns off.

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