External Enable, Spindle CW & CCW Buttons (HAL Support)

Hi All, 

Could I please have some help with some custom HAL?

Hi I'm Steve, and I'm in the process of converting a Bridgeport (clone) to CNC using the MESA 7i96s and AC servo drivers. I would like to use the existing manual (hardware) buttons on the milling machine to control the 'machine enable' and the 'spindle'. So far, I have LinuxCNC all up and running with Servo and spindle control running fine through LinuxCNC. I have physically wired the buttons to the inputs of the MESA card. In HAL configuration I can see the input buttons switching when I press them. What I'm stuck with is the custom HAL code to connect the button signals to control the following:

1. Machine Enable
When the physical enable button is pressed it latches through a contactor circuit and thus provides the MESA card with a latched 'on' input. When this is on, I would like the 'machine,is-on' to be triggered. And vise verse, when the input is off, the 'machine.is-on', should be cancelled.

2. Spindle CW 
When the physical Spindle CW button is pressed it latches through a contactor circuit and thus provides the MESA card with a latched 'on' input. When this is on, I would like the it to act as a M3 command . And vise verse, when the input is off, it should be like a M5 command.

3. Spindle CCW 
Again, when the physical Spindle CCW button is pressed it latches through a contactor circuit and thus provides the MESA card with a latched 'on' input. When this is on, I would like the it to act as a M4 command . And vise verse, when the input is off, it should be like a M5 command.

I have read all I can in the HAL manuals and I have to say I'm lost with what code is required and where I should put it!

Any help will be gratefully received. 

Best Regards 

Steve 

Maybe like this:

# --- MACHINE ENABLE ---
net machine-button-panel <= hm2_<your_mesa_input_pin_here> => halui.machine.on

# --- M3 PANEL BUTTON ---
net m3-cmd-panel <= hm2_<your_mesa_input_pin_here> => halui.spindle.0.forward

# --- M4 PANEL BUTTON ---
net m4-cmd-panel <= hm2_<your_mesa_input_pin_here> => halui.spindle.0.reverse


Since you don't want a panel button for M5 you will need to run the signals 'm3-cmd-panel' and 'm4-cmd-panel' through a 'not' component. Those two negated signals could then be passed through a 'oneshot' component each and the resulting pulsed signals combined with an 'or' component and that output fed to 'halui.spindle.0.stop'

Easier would be to have a separate button for spindle stop:

# --- M5 PANEL BUTTON ---
net m5-cmd-panel <= hm2_<your_mesa_input_pin_here> => halui.spindle.0.stop

[edit]
The 'oneshot' component can also be set to trigger on negative edges using parameters so the 'not' component could be omitted.
linuxcnc.org/docs/html/man/man9/oneshot.9.html
 

That's some good advice