RB4 on the EBB

[mauimaker]

Hi,

 I love the egg-bot and this forum/community. Sparkfun is coming to my little town and I signed up. Thank you to EMS too. 

I’m trying different I/O pins on the EBB. I soldered pins into RB4, I have a harmless LED light plugged into it. The light is constantly on. When I do a test plot the light blinks on and off according to the nature of the plotted drawing. But it seems to me that the on/off are reversed. Using the pen arm for comparison, shouldn’t the light be off at first (the equvilant of “pen up”) and intermitantly flash on during the plot (the equivalant of “pen down”)? 

I’m guessing this is easy to fix in the softwear. The EBB comands pages is not clear to me. Where do I go to type those commands to enable B4 on the board?

Thanks

[Windell Oskay]

IIRC, the otherwise unused I/O pins are tristated at turn-on, and have floating values that can fluctuate, which is what you are seeing.  To use one as an output, you’ll need to set it to be an output first, and then set what value you want it to have.  

We use one of the other I/O pins (B3) as the digital output to control the Eggbot engraver attachment, and have found that it’s typically at ~2V at turn-on.  If you’d like to see how it works, open up the Eggbot software (eggbot.py) within the Inkscape Extensions folder, and look through the code.  The command to initialize B3, and set it to high output is as follows:

PD,B,3,0 # Set pin D3 direction (output)

PO,B,3,1 # Set pin D3 value (high)

To set it low again, 

PO,B,3,0 

This isn’t so different from the pin direction and pin value commands that one uses in Arduino.  However, they are sent as serial commands to the EBB, rather than being compiled into the firmware.

[mauimaker]

Hi Windell,

 Thanks for your response.

I have the engraver attachment too. I would like to try it. I have no experience in programming or reading code. Sorry for the stupid question but…

 “Open up the Eggbot software (eggbot.py) within the Inkscape Extensions folder, and look through the code.”

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 I don’t know where to go to find this folder. I have been searching my computer.

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Where to find the extensions on your system

Eggbot’s extensions to Inkscape are text files. There are two text files per extension: a Python program with file extension .py and a menu description with file extension .inx. The syntax of the latter file is that of XML while its semantics are specific to Inkscape [3]. These files are located in different directories on different platforms:

• Linux: ~/.config/inkscape/extensions/
• Mac OS X: /Applications/Inkscape.app/Contents/Resources/extensions/
• Windows: C:Program FilesInkscapeshareextensions

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 I know I have the eggbot extensions installed because I can use them in Inkscape (“Eggbot control” is there and the other extensions too). I updated everything: Xquartz 2.7.4, Inkscape 0.48.2, Eggbot Ext. 2.3.1. Where do I search to find these text files?

I am a Mac user. 

I’m sure it’s somthing obvious.

Thanks again

[Windell Oskay]

In the Finder, from the Go menu, select “Go to Folder…” and enter the following: 

/Applications/Inkscape.app/Contents/Resources/extensions

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