Re: Checking EBB motor voltage from Inkscape

[ragstian]

Hi Brian.

Once again thanks for the detailed explanations, it’s appreciated!
I am “sucking up” the info like a dry sponge!!

For the pen arm code failing doing long moves using the SM command, most of my latest plots have been very fine detailed with a lot of short moves and very few long moves. ( Example ) I also make sure to use the “optimize” feature of the eggbot extension to limit long “air-moves”. To test Iong moves I can make some designs with a lot of long moves. What’s the reported “failure mode”? Loosing steps, failing to move, crashes? Due to the mechanical constraints of the eggbot the pen arm movement is limited to about 900 pixels, by removing the pen arm and using a circular disk (graduated in degrees) much larger pen movements can be simulated. I remember running into problems with large sheet sizes trying to plot a 128000 pixel long line from upper left to lower right corner of the sheet (canvas in Inkscape lingo), this was to make a line spiralling 40 times around the egg. At the time I attributed the problem to inkscape/eggbot/EBB_board using 16 bit numbers (max 65536 or 32768 if signed). Have not tried this experiment lately with latest versions of inkscape/eggbot/EBB_board.

I have one question regarding the motor current setting calculations, where does the 46mA at 0 counts come from? I have studied the A4983 motor driver data sheet but could not find any relevant info. (Reading datasheets is difficult (for me at least), try the TI Tiva™ TM4C123GH6PZ Microcontroller datasheet – 1452 pages!)

Quote: “You can see the changes yourself if you compare SVN 289 with SVN 290.”
Again, where to find? ;-)

Here are my new eggbot.py and eggbot.inx files eggbot.zip

Please be aware that this only works on EBB firmware version 2.2.3 and higher.
EMS does not recommend to upgrade past version 2.0.1 d.t. a possible
pen arm movement bug in the newer versions.

RGDS
Ragnar