I see a lot of these for sale and would like to experiment with one. Does anyone have info on how they interface to a PC? Does it show up as an HID device or is it more like a simple async terminal ending text data? Ultimately, I want to use a microcontroller to read the pendant. Any help or pointers greatly appreciated.
They show up as an HID: Here's some never-completed work from the Laserweb days LaserWeb/lw.comm-server and LaserWeb/lw.comm-server and LaserWeb/lw.comm-server Lots of work in there from Claudio Prezzi
Not for my needs. I want to be able to plug pendants into a grblHAL breakout board like the one I made here.
Would it be easier to get a non-USB one if you're just gonna have a micro read it anyway? Most of the non-MPG wires are settings or LEDs or something, nothing that needs an interrupt. I have mine plugged into a Mesa 7i85 at the minute, though I still haven't set it up in LinuxCNC yet, but it would be fairly trivial to interface with a micro board.
This is the one I bought: https://smile.amazon.com/gp/product/B07CZ7F3Y3/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 Feels solid, metal body, decent internals, comes with a little bracket to hang it on, it's nice. Great price too. I looked for a while before I settled on that one. Just comes with a spray of maybe 28ga wires sticking out the end, and a key card in chinese (but Google Lens and a multimeter can translate it).
Thanks. I like that. May well get it. However, I still want to support the USB versions as I am working with others to help make grblHAL a "plug-and-play" replacement for the current 8-bit GRBL. Each piece should be simple to assemble and use.
After looking at it a bit more, it looks pretty usable. On the pulse generator, I assume that A and B are quadrature encoded. Not sure why bar A and bar B are needed unless there is some sort of anti-glitch work that needs to be done. grblHAL can take I2C input so my micro (probably a teensy LC or maybe even an arduino nano) would be a slave and interpret the pendant switches and quad output. The master I2C side would feed grbl commands.
Yeah, that sounds eminently doable. It's been a very long time since I scoped its outputs, but I believe it was quadrature, yeah. It may just break out the inverts because some controllers demand it- I can't say I've ever interfaced with a Fanuc or Siemens controller, but I wouldn't be surprised if they want differential inputs. Just looking at grblHAL over here, looks pretty cool. Would be nice to get a system as simple as grbl and physically plugging components together with the power and capability of linuxCNC. Sounds like what that new thread in Concepts and Ideas is talking about, really!
one other questions, the ad shows a card that mentions 5V. I assume that since it's just switches, 3.3V would be ok too. Is that right?
Yes, Terje, the guy behind grblHAL, is using LinuxCNC as his model. Already he has a number of G and M codes that go beyond - like M62-65, pin control. Super easy to support random hardware. I have it working on my breakout board to control extra relay drivers.
On the switches, that would be fine. On the encoder, I'm not sure, it'd depend how the photodiodes are set up? Plastic body, apparently I misremembered. But a pretty thick, reinforced casting. Could even be glass fibered, hard to tell. Yeah, might have to look into it for my next machine. I'll need extra codes and hardware, but if I can avoid dealing with HAL and Mesa electronics, I'll be a little happier!
A quick follow up on this. I got the pendant that Rob suggested and have it hooked up to a Teensy. Got all the switches and encoder working. Everything runs just fine on 3.3V. Even the power indicator LED lights up just fine on 3.3V (docs say 24V!). Next step is I2C to the grbl/HAL board and integrating into grbl/HAL. I'm still going to investigate USB based solutions but this gets me going with one less variable to deal with.
Phil, any update on this? I just bought one of your kits on Tindie and would love to plug one of these in
Wow, that was a year ago... Thanks for buying the kit. I did get it working with a micro - actually several iterations: a Teensy LC based one and one using an Atmel ATTiny. Both plug into the I2C header on my board. Sadly, there is no plugin for grblHAL. After playing with it and some thinking, I decided that the right direction was to be able to use the USB based MPGs out there. The current board doesn't support it but a new Pro board I am working on has a host USB socket so you can plug one into it. There is still the matter of a grblHAL plugin. You can find details on that board on github at terjrio/grblHAL/discussions/breakout boards.
