shake to reset!

A project log for Etch-a-CNC

An etch a sketch type controller for CNC machinery

ljlj 06/17/2014 at 15:470 Comments

I’ve been working on the controller slowly these last few days. I got a 9-axis imu hooked up now and have it controlling the reset. So far it just resets when you turn it upside down. No shaking required. I tried reading the X-Y data when it was upside down and being shaken but it just came in as a jumble of quickly changing numbers. I think its good enough for now. I’ve also switched to using the integral push buttons in the encoders for the up and down of the Z axis.

I’ve got it all stuffed into the frame to test. The problem is the cables for USB and HDMI are all long and thick. So I’ve been soldering in some direct connections where I can. So serial from arduino to raspi is direct over gpio instead of USB, one thick cable gone. And for the video from the raspi to the screen has been moved from the HDMI over to the composite video connection. And that connection is also using some bodged on header to do the connection instead of the barrel connections. Second thick cable out of the way. now it’s a mess of rainbow cable crisscrossing inside making all of the needed connections. I’ve made a resistor divider for the tx-rx from the arduino to the raspi since it needs to step down from 5v to 3v3 so as not to fry the raspi. Progress is coming along nicely.  

I've found an old printer on the street that will be serving as the donor for the paper transport.  I'm not sure if I'll be able to use the paper path intact or not, but if nothing else I'll be able to use the rubber rollers to move the paper around.  I'm also planning on refitting the printhead carriage with an exacto knife to cut the roll after each picture.  I'm planning on doing the disassembly and parts harvest with my kids.  Hopefully the parts harvest will yield some good results.  The last few printers I've taken apart have been somewhat disappointing.  The older dot matrix and lasers always have better parts than these newer inkjet all in ones.