Arduino Mb2hal question (solved)

Hi

I am working on a Wire EDM machine and i need Linuxcnc to control the water conductivity by switching a solenoid valve to divert water through a de-ionising resin filter.

I am measuring the water conductivity (EC) using this setup with an Arduino Uno.

Arduino EC meter

I want Arduino to report the EC to LCNC so that i can control the pumps and valve from one platform

I loaded Mb2hal using this info: Mb2Hal

Now my problem:

I cant find a decent source of information on how to setup the Arduino code to report a float or u32 value to LCNC. The Arduino code seems to write the input registers to the output registers but i have no idea what these registers contain or how to use them.

On the LCNC side it seems to load without issues and i can see the pins in hal. I am aware of how to change the variable types in Mb2hal, but the default code linked sets up float values so that is ok.

Any tips would be appreciated.

P.S my fallback is to use the remaining arduino pins as paralell bits and link that to inputs on my 7i76E and decode the paralell binary data to S32 in LCNC but this seems a bit stupid...

Two ways you can do that:
Set arduino to output frequency depending on EC and use the 7i76 encoder to count that frequency, set encoder counter mode to 1 so it outputs just the velocity and use a comp (comparator) component in LinuxCNC to output to a pin at a preset threshold,
Use LinuxCNC components to convert u32 to float or vice versa:
linuxcnc.org/docs/2.4/html/man/man9/conv_u32_float.9.html
linuxcnc.org/docs/2.5/html/man/man9/conv_float_u32.9.html

you can use the USB and your own HAL comp to report whatever you like to the HAL

see the XHC Handheld component it reports back and forth 1000times a second

Thanks.
I also thought of the encoder counting option as a possibility. Will be low frequency though because I will have to use a software encoder. The 7i76e encoder is occupied already.

Would be nice to get MB2hal working though because I can then simplify a lot of wiring from the water level sensors and so on.

I just uploaded my code to github, It is what I use to send data both ways from an arduino to linuxcnc.

github.com/herongcachoeira/ComLinuxcncArduino

Hope this helps a bit.
The code was not intended to be shared so i did not bothered with comments, sorry!

Ok. I managed to solve this issue.
The serial port was incorrect.
I checked dmesg before and set the serial port in the mb2hal config correctly the first time but somehow this changed. I don't know how these are assigned and if they can change.....maybe it was just a mistake.

Anyway. It works now. Thanks for all the valued suggestions.

Henk