Ohmic sensing, what's best to use ?

i've read it ans yes it does but it's more fucused on THC than probing

jay1st wrote:

rodw wrote:

That depends. You have no idea how hard it was coming up with it! Be sure to learn how to use halcompile and write your own components. A lot of fun and Linuxcnc's best kept secret! I love it...

That is where i lack comptency, coding and understanding the codes !
I can do some stuff with an arduino, but C and Py is too much for me, i need to grasp how the HAL system works and so on...

If you are coding an Arduino Sketch, you are programming in C. Think of the LCNC servo thread as being the loop() function in Arduino and a component as being a function called from the loop() and you are in business.

phillc54 wrote:

rodw wrote:

[If you are coding an Arduino Sketch, you are programming in C. Think of the LCNC servo thread as being the loop() function in Arduino and a component as being a function called from the loop() and you are in business.

That is a neat way of looking at it.

Well technically, the servo thread is an Interrupt Service Routine (ISR) attached to the timer interrupt so it would be a timer interrupt in Arduino speak... If you have not used interrupts (both timers and hardware) with your Arduino scripts you have not lived!. Hardware is great to read encoders and timers interrupts are great for stepper step generators.

here is simple primer quite interesting to read about capacitive sensing / frequency

ssudl.solent.ac.uk/id/eprint/3497/1/Test results for a capacitance-based corrosion sensor - BINDT 10-10-2016.pdf

phillc54 wrote:

I haven't done any interrupt stuff on an Arduino. In an earlier life if I needed that sort of thing I used 8748h/9h written in assembly code.

Its a long time since I wrote assembly. C does it all for you really!

Interrupts in arduino are very usefull and keep things tidy and speedy when set up correctly

Ahh ok that's why on some "services" in the HAL files it starts with Servothred

So just have a look at the source of some of the components here
github.com/LinuxCNC/linuxcnc/tree/master/src/hal/components

So all you need to do is to type "halcompile --install mycomp.comp" to compile and install.
If you have not compiled LCNC from source, I think you need to use sudo but I've never ever run linuxcnc other than compiled from source...