Topics

1

Brains Development / Brain for encoder to DRO via modbus

« on: June 30, 2009, 12:29:08 AM »

Hi all

I have an encoder on each of my mill axes connected to a cnc4pc M11 modbus board via serial to Mach3.  I am trying to write a brain to display each axis position in a DRO when my machine is under manual control.  This card decodes each encoder and uses three holding registers to store the counts.  I need to grab the values, scale them, then display them in some OEMDRO's.  I've put these DRO's on a separate screen which I can change to for manual control, leaving the standard Mach3 screens essentially unchanged for G-Code control.

My first working attempt for one axis only looked like:

MOD 64 (input) -> formula A * 0.01016  -> OEMDRO 1000

This works well and is very encouraging.  To be of any practical value however I need to be able to re-zero the DRO using an on-screen button.  I can't seem to find a way to capture the input value in the brain as an offset (when the button is pressed) and retrieve it for subtraction from the current value as it is sent to the DRO.  Any ideas for a solution or alternative approach welcome.

Regards, Ian

2

General Mach Discussion / Mouseless operation of Mach 3 using programmable POS keyboard

« on: June 16, 2009, 08:05:16 PM »

Hi All

It seems everyone has a different story about recycling computer gear into their projects and I thought someone might find this one interesting.  I picked up some ex-restaurant programmable POS keyboards on ebay last week and am trialling one for my cnc mill conversion.  The keyboard layout is 16 wide by 8 high with tactile feedback and a polycarbonate overlay.  Each key is re-programmable for make and break so a single button press can perform any sort of hot-keying.  It's also re-legendable so I'll be able to label the keys for start, run, etc. as required.  I've pulled one to pieces and it will be a snap to mount the key matrix and controller behind a panel together with my lcd screen so it hopefully ends up something like the panel on a commercial cnc machine.

The idea is to reprogram the keyboard to perform all the common functions required to drive Mach3 so as not to need a mouse (I'll keep a cordless usb trackball handy just in case!).  I'd also like to maximise the screen for display by removing the buttons I don't need from the screen.  The problem is how to program a hotkey screen button to respond to the keyboard hotkey sequence without a button being displayed on the screen or using up screen area?  I have tried making the buttons very small (like 10 x 10 pixels) so they are not visible but then they are too hard to find later.  Is there any way to create a hot key that performs the same function as a button without using an on-screen button?

Any ideas appreciated.

Kind Regards
Ian
Brisbane, Australia

3

General Mach Discussion / Real time display of encoder position in DRO's on main screen

« on: April 21, 2009, 10:45:04 AM »

G'day All

I have hooked up a couple of USDigital encoders to the X and Y axis of my mill and fed them into a cnc4pc C1G breakout board into Mach3.  So far so good, I've managed to get some pin lights flashing in the "Diagnostics" screen and the position counts logically up and down in the "Settings" screen.  In the main screen the DRO just stays at whatever value it was before until I press the "To DRO" button.

Is there any way to get a real time readout of the encoder postion to display in the main screen?  Alternately is there a straight "DRO mode" for Mach3 which will just display the actual table postion reported by the encoders?  It seems possible to devise a custom screen to do this using Screen4 or similar but my initial attempts have been a bit discouraging.

Any advice or assistance greatly appreciated.

Regards, Ian

4

Screen designer tips and tutorials / Newbie can't get an image in Screen4

« on: March 13, 2009, 06:27:50 AM »

Hi
Rank Amatuer, I have created a bitmap png file, saved to the Mach3 bitmaps directory, loaded Screen4, started a new design, clicked on the Image icon at left then click on the middle of the white screen and nothing happens.  I have watched the video a few times and the box that appears on his screen just doesn't come up.  Any ideas what could be wrong?  Does this software need to be licensed to work or am I just missing something obvious?  Any assistance greatly appreciated.
Regards, Ian