It’s fair to say that there can’t be many developers who have found the need for a rotary telephone dial as a peripheral for their Linux computer, but in case you are among them you might find [Stefan Wiehler]’s kernel driver for rotary dials to be of use.
It’s aimed at platforms such as systems-on-chip that have ready access to extra GPIOs, of which it will need a couple to service the BUSY and PULSE lines. There are full set-up instructions, and once it’s in place and configured it presents the dial as though it were a number pad.
We like this project, in fact we like it a lot. Interfacing with a dial is always something we’ve done with a microcontroller though, so it will be interesting to see whether it finds a use beyond merely curiosity. We can already see a generation of old-school dial IP phones using Linux-capable dev boards. He leaves us with a brief not as to whether Linus Torvalds would see it as worthy of mainline inclusion, and sadly however much we want things to be different, we agree that it might be wishful thinking.
If you’d like to use a dial phone, there can be simpler ways to do it.
Header: Billy Brown, CC BY 2.0 .
Nice! I have built something similar, but with an Arduino as a HID Keyboard for the rotary dial, sending “0”-“9” and triggerhappy for the actions.
https://github.com/Harvie/RotaryDial
Users who actually shower wouldn’t hurt, either.
Heh, there are commercial products sold for audio and video editing that are mostly used for scrolling along timelines that natively just send page up and page down keystrokes.
In some fictional(?) universe somewhere, Linux has a kernel module for this dialer, or rather, the thing the dialer connects to, which supports 7- and 8-“digit” dialing.
awfully s l o w . . . is the main reason this is not used. But a real cool addon for an homebrew toy.
Does the OS have to be constantly polling the GPIOs? That might not be so great when multitasking. Or is it using some sort of interrupt?
SOCs will have interrupts on at least some of the GPIO pins. You would definitely want to use them.
I had a quick look through the code and it does appear to be using interrupts.
That’s awesome. I always loved to “hang up” Linux! :D
Hey don’t knock it. I was a telecom electrician when this technology was all we have around the world. It was all mechanical and the size of a transistor which was very rare was the size of a quarter. Linux has been my retirement hobby and I love it .
Nice is it for sim card working? I see like I feel if I use foldable giant tablet ( it seems like Lenovo Pad or like laptop for Linux based, I understand correctly?”
I hope it works for Lenovo foldable pads if I buy it without Windows. Only penguin forever used laptop without bringing tablet or smartphone