First steps with 6i25+7i77 : how to read a home switch ?

Hello,

I am starting with LinuxCNC and MESA boards.

Reading various posts on the forum, I managed to connect all and supply the field power with 24v DC.

I started with what andypugh showed in this topic : forum.linuxcnc.org/9-installing-linuxcnc...nuxcnc-configuration

andypugh wrote:
Open a terminal window and type:

Code:

sudo dmesg -c halrun loadrt hostmot2 loadrt hm2_pci show pin *5i25* exit dmesg

The "show pin" displays all the HAL pins created by the firmware on the card.

I am able to see all my I/O from the 7i77 :

Using again andypugh suggestion from this topic : forum.linuxcnc.org/38-general-linuxcnc-q...-done-init-mesa-6i25

andypugh wrote: Just type this at the terminal:

Code:

halrun loadrt hostmot2 loadrt hm2_pci

(Nothing happens with the card without being attached to a real-time thread)

Code:

loadrt thtreads addf hm2_5i25.0.read thread1 addf hm2_5i25.0.write thread1 start show pin

(I am guessing the next pin name, but it will appear in the list created by the command above, and you can use tab-completion to do most of the typing)

Code:

setp hm2_5i25.0.led.cr0 1

Should turn an LED on

Code:

setp hm2_5i25.0.led.cr0 0

Should turn it off

I played with the two leds first.

Now I would like to read a home limit switch. I read from the 7i77 manual that I have to wire my switch to power field and to an input terminal of the 7i77, I am ready to do this.

Keeping andypugh hal instructions here above, is "addf hm2_5i25.0.read thread1 " suitable to read such a home limit switch input in case of a 7i77 ?

My plan is to observe from Halscope the changing state when toggling the switch.

Thank you for help.

My machine rebuilt can be seen at : here

Yes, you need to load the driver and add the read function to a thread.

To monitor the output you might like to try:
(you can repeat this command to open as many halmeters as you need).

To test outputs (which need the write function added to a thread) you can either use "setp" as you did with the LEDs or linuxcnc.org/docs/2.7/html/man/man1/sim_pin.1.html

Thank you Andy it worked like a charm.

Here the short shooting link : Here