TL;DR: Would it be possible for ShopBot to release some information about the Handibot's communications protocol?
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Heyas folks. I'm a Kickstarter backer of the Handibot, and have enjoyed tinkering a bit with it. So far, I've only made a few small signs with my Handibot, and would like to do a bit more. I'm more of a software person/developer than a woodworker, and my current project idea is more toward tooling than end result. But to pursue it, I need a bit of information to do so, and I was hoping that the ShopBot folks would be able to help out.
Right now, I'd like to attempt a semi-automatic Z leveling tool for my Handibot. The basic idea is that I'll place a moderately large copper-clad board below the Handibot, and attach a test lead (like an alligator clip) to the bit. When the bit touches the copper-clad board, they'll close a circuit, acting like a switch. My thought is that I could program a Raspberry Pi or similar small computer (or even possibly a microcontroller) to slowly drive the Z-axis down until it detects this.
To do this, I need to be able to communicate with my Handibot over USB without the assistance of the ShopBot control software. I've figured out some of how this would work, so far: It seems that my Handibot exposes a serial-over-USB connection. It looks very likely that this communication is mediated by the Silicon Labs "USBXpress" library. While figuring out how USBXpress does it's signalling might be an obstacle, there are a number of open source leads in this direction. Far larger an obstacle is trying to figure out the serial protocol between ShopBot control software and the MCU inside the Handibot.
Now, I realize from reading other posts that ShopBot is developing a newer model of control board to make interfacing easier. However, this direction is somewhat unsatisfying to me. Other than my wish to be able to program it, my Handibot currently works perfectly well. The thought of purchasing and attempting to install a new control board feels like a large cost to obtain my goal.
Thus my question/request: is there any available documentation about the serial communications protocol used by the ShopBot 20x series control board inside my Handibot? If no, would it be possible for ShopBot to release some documentation on this? Or, barring that, to release the source code to a small portion of the ShopBot control software responsible for mediating the lowest level communications?
Thanks!
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Shawn Walker
Edited 1 time(s). Last edit at 03/04/2014 08:46PM by Shawn.Walker.