[Delron]

Hi All,

I've been searching the forums and web for info about a project I'm interested in taking on, but having trouble finding concrete answers.
I hope someone smarter than me can point me in the right direction.

I'm building a Pendant and trying to find info for hooking it up electrically and configuring LinuxCNC to utilize it.

I'm open to either Parallel port or USB for connections. I have a Quadrature encoded hand wheel as well as 14 buttons on my pendant. I need to decide what functions I'm interested in having each button perform. I'm expecting to hook up the buttons as a 4X4 array requiring 8 inputs and the MPG encoder requiring x-number of inputs.

I'm not looking to re-invent the wheel here, so no C++ or other programming etc. I can work with HAL to get it all up and running, but need advise on the details.

Can anyone help or point me in a solid working direction?

Cheers!

Dale

[wendtmk]

Lotsa resources on the LinuxCNC website and wiki:

LinuxCNC.org

LinuxCNC Documentation Wiki: LinuxCNCKnowledgeBase

This should get you started:

LinuxCNC Documentation Wiki: Hooking Up A MPG Pendant

[Delron]

Thanks, I'm asking over there as well.
My problem is a little more complicated than what I've found for help within the linux examples or community so far.

The problem I'm facing is;

I know I can use a USB interface (HAL Joypad example) and have lots of inputs that I could tie the keypad to, but I cannot find if it's possible to connect a Quadrature encoder (Hand wheel) to the USB inputs using a USB HID connection board.

I also know I can tie the encoder in using the parallel port and have a few inputs left over for some buttons, but not 14 or 15 buttons unless I can use matrix keypad scanning on the parallel port, but I cannot find any info to do that.

So my problem is, I do not know how to connect an encoder AND 14 keys to one or the other ports.

Cheers! And thanks for any help anyone can offer.

Dale

[PCW_MESA]

Its certainly doable with a single parallel port and the matrix_kb component

For example if you set the parallel port to "in" mode you have 13 inputs and 4 outputs
This would allow for example 16 keys (8 in x 2 out matrix) and leave 2 outputs for LEDs etc
2 inputs for MPG encoder and 3 spare individual inputs for mode switches etc

Is this trivial? no

Is it doable with help from linuxcnc forum members: absolutely

This setup has some advantages over USB interfaces in that it has basically 0 jitter (all real time)
so response is excellent (USB will always have variable delays up to the 50 or more ms region)

[dharmic]

Can LinuxCNC handle serial interfaces or can you add a plugin for new devices to it? If so, and you have access to (either yourself or others) electronics, embedded and Linux environment programming...

Other thing to look at is a small microprocessor (arduino based on an ATMega32u4, for example) hooked up with something like a Bourns EMS22 (1024 ppr encoder with its own 3 wire serial protocol, easy to bit bash) and maybe a MAX7300 I2C IO expander for the keys.

Using the arduino setup it's a piece of cake to program, you'll need to get a PCB made for the pendant of course, and it will expose as a serial port on the host machine.

[Delron]

Thanks for all the help everyone. I'm going to go with PCW_MESA's suggestion and set it up via parallel port.

Cheers all!

[grg12]

Can LinuxCNC handle serial interfaces or can you add a plugin for new devices to it? If so, and you have access to (either yourself or others) electronics, embedded and Linux environment programming...

Other thing to look at is a small microprocessor (arduino based on an ATMega32u4, for example) hooked up with something like a Bourns EMS22 (1024 ppr encoder with its own 3 wire serial protocol, easy to bit bash) and maybe a MAX7300 I2C IO expander for the keys.

Using the arduino setup it's a piece of cake to program, you'll need to get a PCB made for the pendant of course, and it will expose as a serial port on the host machine.

As far I know linuxcnc has hal module for serial port. And with a bit of python code you can connect to almost anything. I have built simple pendant with salvaged mouse wheel, msp430 processor from Texas Instruments launchpad kit, some 7400 logic and max232 chip. And learned python programming in the process

[burdickjp]

Can LinuxCNC handle serial interfaces or can you add a plugin for new devices to it? If so, and you have access to (either yourself or others) electronics, embedded and Linux environment programming...

Other thing to look at is a small microprocessor (arduino based on an ATMega32u4, for example) hooked up with something like a Bourns EMS22 (1024 ppr encoder with its own 3 wire serial protocol, easy to bit bash) and maybe a MAX7300 I2C IO expander for the keys.

Using the arduino setup it's a piece of cake to program, you'll need to get a PCB made for the pendant of course, and it will expose as a serial port on the host machine.

That's probably your best bet and probably the most flexible, as well. It's how I'd do it, at least.

[rythmnbls]

Delron, have you seen ArcEye's pendant ? http://http://www.mgware.co.uk/ its under the HAL components drop down list.

Regards,

Steve.

[Delron]

Can anyone help me with the matrix_kb component?
I can't find anything to guide me implementing it on a parallel port.
LinuxCnc doc is way to confusing for me.

Cheers!

Its certainly doable with a single parallel port and the matrix_kb component

For example if you set the parallel port to "in" mode you have 13 inputs and 4 outputs
This would allow for example 16 keys (8 in x 2 out matrix) and leave 2 outputs for LEDs etc
2 inputs for MPG encoder and 3 spare individual inputs for mode switches etc

Is this trivial? no

Is it doable with help from linuxcnc forum members: absolutely

This setup has some advantages over USB interfaces in that it has basically 0 jitter (all real time)
so response is excellent (USB will always have variable delays up to the 50 or more ms region)

[svenakela]

Can anyone help me with the matrix_kb component?
I can't find anything to guide me implementing it on a parallel port.
LinuxCnc doc is way to confusing for me.

Cheers!

Join the mailing list. You have a lot of knowledge there.

[Delron]

Join the mailing list. You have a lot of knowledge there.

Umm, what?

[svenakela]

Umm, what?

What what?
The primary means of contact is to join the users mailing list >> Community

[Delron]

What what?
The primary means of contact is to join the users mailing list >> Community

If you read post #3, you'd see that I said I was already asking over there at the LinuxCnc Community. There is next to no info on the matric_kb function there or anywhere. That is why I was asking in more than one forum.

BTW, you saying "Join the mailing list. You have a lot of knowledge there." really does not convey much meaning. I'm a member there, and did not know what you meant.

Cheers!

[Delron]

Update.

I have solved all my questions with help of some very knowledgeable and friendly people.
My pendant is working very well, just needing to assign a few more functions to buttons to wrap it up.

Cheers all!

[svenakela]

If you read post #3, you'd see that I said I was already asking over there at the LinuxCnc Community. There is next to no info on the matric_kb function there or anywhere. That is why I was asking in more than one forum.

BTW, you saying "Join the mailing list. You have a lot of knowledge there." really does not convey much meaning. I'm a member there, and did not know what you meant.

Cheers!

Did you ask at the forum or the mailing list? I can't see any matrix_kb related discussions since April 13 in my mailbox (which is a 7i73 inputs question) and before that I have to reverse to September last year.
A lot of the expertss only uses the mailing list, no forums touched so to say by the black hats.

[svenakela]

Update.

I have solved all my questions with help of some very knowledgeable and friendly people.
My pendant is working very well, just needing to assign a few more functions to buttons to wrap it up.

Cheers all!

Great! I assume you document it on the wiki.

[Delron]

Did you ask at the forum or the mailing list? I can't see any matrix_kb related discussions since April 13 in my mailbox (which is a 7i73 inputs question) and before that I have to reverse to September last year.
A lot of the expertss only uses the mailing list, no forums touched so to say by the black hats.

Forum. I don't like mailing lists. Too much distracting chatter.

[askjerry]

@ Delron : I'm interested to see what you have accomplished... have you documented it on-line at all? As I'm just really getting into HAL and pyVCP... I'll take any tips I can find.

@ svenakela: Mailing lists... the problem (as I see it) for a mailing list is that usually they are text only, which means no images to help in explanations, no video, no attachments. We have a mailing list for the Robot Group that I'm a part of... and usually the only way to get things done is to go off-line and use email, phone, etc. Additionally, in a forum things are segmented into topics... and you can (usually) locate things quickly. I haven't been on your mailing list... but on the ones I have been... many times the headings are useless... like "Hey it works" might be the heading for connecting a USB joystick to a controller. :-(

I'm willing to take a look... can you provide the URL?

Thanks,
Jerry
I have been documenting my progress... needs some updates... but: Askjerry... Everyone else does.

[wendtmk]

Jerry,

The LinuxCNC mailing list allows attachments. Get them all the time. This includes images, pdf's, videos, etc.

Mark