THCAD

@tommylight

Tom, have you successfully run a THCD into a parport?
If so would you mind sharing the connections and settings, I would like to add them into the docs.

Yes, i was just searching for it.

Found it, it's in the torchud.hal.

Thanks Tom.

Next question.
Is the Mesa THCAD the only current way of getting a plasma voltage into LinucCNC in realtime.

phillc54 wrote: Thanks Tom.

Next question.
Is the Mesa THCAD the only current way of getting a plasma voltage into LinucCNC in realtime.

In practice yes. The 7i76e has some analog inputs but not really designed for plasma and nowhere near as accurate. I think some of the mesa cards may have a more accurate A/D converter option but I'm not sure if they work with linuxcnc.

I am not aware of nay A/D converters for Linuxcnc.

LM331 is an option for DIY but very limited, it is also a voltage to frequency converter but it can do 10Khz i think, needs a simple circuit and an opto coupler to isolate it form the plasma side.
Anything else and the THCAD will win anyway you look at it.
I do have those LM331 collecting dust here, but i got Mesa THCAD, one working on a machine and 4 on the way to me (quite a long way due to this CCP cr@p ).
On the DIY side, there are also arduino based THC and they do work, again quite limited, but usable for sure. Pressed for time as i have plenty of them also, and i do have ESP32, several of them, was thinking of using that (12 BIT analog inputs, several of them, WiFi, BT etc, 2 processors at 240MHz) to send data wirelessly to the PC but the lag would prove unusable and the HF/HV interference would drop the connection, most probably.

I think the Arduino way would use serial and that would only be userspace wouldn't it.

Well there is also Ethercat. There would be a n A/D converter available there. Pretty sure Grotius did it that way.

rodw wrote:
I am not aware of nay A/D converters for Linuxcnc.

Any voltage to frequency converter will do, but properly separating them from the plasma is another subject entirely.
I can build one for about 10$, but i never did, i just buy Mesa and be done with it. Mesa THCAD has some sophisticated isolation stuff in there, and having 1MHz bandwidth is just the icing and the cherry on the cake.

I am looking at some document changes and I want to mention some practical options for users.