Today in old school nostalgia our tipster [Clint Jay] wrote in to let us know about this rotary dial.
If you’re a young whippersnapper you might never have seen a rotary dial. These things were commonly used on telephones back in the day, and they were notoriously slow to use. The way they work is that they generate a number of pulses corresponding to the number you want to dial in. One pulse for 1, two pulses for 2, and so on, up to nine pulses for 9, then ten pulses for 0.
We see circuits like this here at Hackaday from time to time. In fact, commonly we see them implemented as USB keyboards, such as in Rotary Dial Becomes USB Keyboard and Rotary Dialer Becomes Numeric Keypad.
One thing that makes this particular project different from the ones we’ve seen before is that it doesn’t require a microcontroller. That said, our hacker [Mousa] shows us how to interface this dial with an Arduino, along with sample code, if that’s something you’d like to do. The schematic for the project shows how to connect the rotary dial (salvaged from an old telephone) to both a 7-segment display and a collection of ten LEDs.
The project write-up includes links to the PCB design files. The guts of the project are a 4017 decade counter and a 4026 7-segment display adapter. Good, honest, old school digital logic.
Imagine how younger-generation-theft-resistant your car would be if it used an ignition kill system disabled via rotary dial, and a manual transmission.
:-)
Wow, you have a mean streak.
And you lived in a valley, with stop signs on both hills, on the only road in and out.
You have to use the rotary dial to input the time displayed on an analog clock. Checkmate.
Damn you’re evil! ;-)
Add in something about a cheque book (*) and you’ll confuse everyone but the Americans.
(* Calling it a cheque book would confuse the Americans though.)
Calling it a chequier and you’ll consude everyone but the French
in a few years, the younger-generation-anti-theft device will be a steering wheel.
The whole “manual transmission is a theft deterrent” thing is outdated. Current auto thieves come from countries which still drive manual.
Easy to guess. 1111
Easy to guess. 1111.
Easy to guess. 1111
Is anyone else seeing a nixie tube, rotary dial calculator or is it just me?
You can still use a rotary phone now on regular phone line and you technically control a very complex digital/microprocessor equipment at the phone station from your home by dialing pulse.
I hooked up a ’90s stereo to the television earlier this week. Yesterday, my 18 year old daughter went to turn the volume down and turned it up instead. I realised she’s never used a volume knob before.
A few shower/bathtub knobs are turn to the right to turn off. Might be what she was accustomed to using.
My “favorite” is gas valves. Like on a gas stove or a grill.
Off and Max are adjacent, ‘barely on’ is as far from Off as it can get.
I suppose there is a mechanical reason they make them that way but it is weird. And yes, I AM old enough to have started with rotary phones.
You go through “max” as you light it, then keep turning to desired flame?
Agreed that it’s totally weird.
Bonus points for someone who prints up a 16 – hole dial for inputting hex….
Whomever can tell me what letters are missing from a rotary dial will win a thousand points good for nothing!!!!
QZ?
Very good!!
A thought: “Dial zero to enter a unicode character”
Yes, I just made it even more torturous.
Circa 1963, (Yup, I’m old) I made a binary counter (ones and zeros) using 2n404 transistors in Eccles-Jordan flip-flops. The input device was a rotary dial with incandescent bulb indicators. It was for a school science fair.
Might be good for a nuclear briefcase, gives the user time to think.
Apart from that it is indeed only good for various forms of torture.
This to me was the best usage: https://hackaday.com/2022/09/10/the-open-source-rotary-cell-phone-two-years-later/#more-552238.. No big succes, apparently :-(
I think the cell modem was a GSM or 2nd gen. There is room for an update!