How would I make this wheel and number pad (video and pic included)

Thread Starter

TogetherInElectricDreams

Joined Jan 23, 2019
183
Hello everyone,
Some months ago I asked about a toy microwave panel but realise I didn't really know what I was looking for, I have since seen this (9 second) video and wondered how to make it. Video is of a scroll wheel that changes numbers, when you press it it turns on a light and the counter counts down, when the counter reaches zero the word End appears, the light goes off and it beeps.

If I could I'd like to add the function of the timer stopping if the door is opened and the maximum number one can scroll is 15 (or 10 if easier).

As I explained before, I've never done anything like this before but I am willing to learn, if anyone knows of a video I could watch or a blog I could read I'd be grateful I didn't know what this was called to search. Just want to make something special for my son.

Really appreciate any help I can get.

Kindest regards

Full video (9 seconds):
 

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Ya’akov

Joined Jan 27, 2019
9,071
This would be a simple project for something like an Arduino. It could be one of the smaller ones, it doesn’t have a lot of requirements.

You can get 7-segment displays, rotary encoders (the knob), and piezo buzzers and libraries for all of it very easily.

Many people here could help with the specifics, but you should make a plan for what you actually want to build so you can have a BoM (Bill of Materials), schematics/wiring diagrams, and the program that will run it.

The first step is to write a “user story” that describes how it will operate from the user point of view, and then specifications (power source, maximum countdown time, whatever else you can think of). That plan will make building and getting help much easier, and it can often point out mutually exclusive demands and unexpected requirements even on a small project.

Good luck.
 

Ya’akov

Joined Jan 27, 2019
9,071
Thank you Yaakov,

Is what I said not clear enough? Should I write another thread with the BoM?

I appreciate you taking the time to reply to me.
Happy to help. But you can use this thread. The BoM is after the design. So, start with a drawing of what you will actually build, along with a little narrative of what you expect it to act like from a user perspective.

Then, people can make particular suggestions about how to do it, and the BoM follows. If you’d done this a thousand times you wouldn’t really need the list to be so formal, but starting out it is a lot easier if you figure out all the materials for the project at the start (or as close as you can get).
 

Thread Starter

TogetherInElectricDreams

Joined Jan 23, 2019
183
So sorry Yaakov but I wouldn't even know how to post a drawing, I wouldn't know what to draw! *face palm* I posted the video because I thought it would be helpful, should I make a line drawing of the wheel and counter? Is that what you mean? I certainly couldn't do the circuits, I'd never even heard of Arduino before I thought of doing this project! Never done electronics in my life. If you don't mind talking me through it I'll gladly accept your advice, again I really appreciate your time.
 

djsfantasi

Joined Apr 11, 2010
9,156
So sorry Yaakov but I wouldn't even know how to post a drawing, I wouldn't know what to draw! *face palm* I posted the video because I thought it would be helpful, should I make a line drawing of the wheel and counter? Is that what you mean? I certainly couldn't do the circuits, I'd never even heard of Arduino before I thought of doing this project! Never done electronics in my life. If you don't mind talking me through it I'll gladly accept your advice, again I really appreciate your time.
I can help, too. If I understand your requirements, the Arduino Nano can be all that you need.

As a user story, I am looking for:
  • How many digits do you need to input?
  • How many digits are in your display? How many actually will change?
  • How slow/fast should your countdown be? 1 second per digit? Or something else?
  • What do you want it to do when the count is zero?
  • How will you enter the count? I.e. you change the input. How do you know when to stop reading the input and start counting?
  • You want the door opening to stop the count. What happens when you close the door? Start counting immediately or wait for an input to start counting again?
  • How do you want to reset the count to zero? Should you start waiting for s new input? Or something else?
 

Ya’akov

Joined Jan 27, 2019
9,071
So sorry Yaakov but I wouldn't even know how to post a drawing, I wouldn't know what to draw! *face palm* I posted the video because I thought it would be helpful, should I make a line drawing of the wheel and counter? Is that what you mean? I certainly couldn't do the circuits, I'd never even heard of Arduino before I thought of doing this project! Never done electronics in my life. If you don't mind talking me through it I'll gladly accept your advice, again I really appreciate your time.
Start with what you know. Do you want to reproduce, exactly, what is in the video? Probably not, you want to do something in particular and the video is like it, so tell a story about what it would be like to use what you want to build.

If you want exactly what is in the video, which I must say I don’t fully understand the background on, have you contacted the person who posted it?

Basically, explain the problem to get help with a solution. You know what you want, describe it, then people can help you produce all the other things and build something.

@djsfantasi will certainly be helpful, he could do what is seems like you want in his sleep, or at least while groggy.
 

djsfantasi

Joined Apr 11, 2010
9,156
I can help, too. If I understand your requirements, the Arduino Nano can be all that you need.

As a user story, I am looking for:
  • How many digits do you need to input?
  • How many digits are in your display? How many actually will change?
  • How slow/fast should your countdown be? 1 second per digit? Or something else?
  • What do you want it to do when the count is zero?
  • How will you enter the count? I.e. you change the input. How do you know when to stop reading the input and start counting?
  • You want the door opening to stop the count. What happens when you close the door? Start counting immediately or wait for an input to start counting again?
  • How do you want to reset the count to zero? Should you start waiting for s new input? Or something else?
To answer a couple of questions proactively...

Let’s say you have 4 digits, but your count only uses 2. Then the Nano needs 8 outputs. One to select digit 1 or digit 2. Digits 3 & 4 can be hardwired to show a 0. Then you need 7 outputs to display 0-9 on each digit. (Something called multiplexing let’s you use only 8 outputs for two digits).

Then, let’s say you have two thumbwheels to set the digits. Each needs 4 inputs. Or you use a potentiometer (rotating knob). Then you need only one input. In the code for the Arduino, you “map” the position of the knob to a two digit value. Easy peasy, but not wicked (I come from Boston)... but not wicked simple. I can help you with the Arduinos code.

The door opening and closing is another input. Setting and resetting the time, 2 more inputs. Simple on the Nano.

So, with an Nano you have to learn how to connect it, how to write a sketch (that’s a program. I’ll help you with that!) and how to load the program , errr sketch.

I got ahead of myself. Answer the question in post #6 and you and I (and Yaakov) will go from there.
 

Thread Starter

TogetherInElectricDreams

Joined Jan 23, 2019
183
I can help, too. If I understand your requirements, the Arduino Nano can be all that you need.

As a user story, I am looking for:
  • How many digits do you need to input?
  • How many digits are in your display? How many actually will change?
  • How slow/fast should your countdown be? 1 second per digit? Or something else?
  • What do you want it to do when the count is zero?
  • How will you enter the count? I.e. you change the input. How do you know when to stop reading the input and start counting?
  • You want the door opening to stop the count. What happens when you close the door? Start counting immediately or wait for an input to start counting again?
  • How do you want to reset the count to zero? Should you start waiting for s new input? Or something else?
Thank you so much for your questions and helping be clear about my requirements. I am not sure if you saw the video but I will attach a picture to make it all clearer. Here are my answers
I need to input 2 digits
4 digits in the display but only 2 will change when the wheel is turned, minimum number the wheel can set is 01
Countdown will be 1 second per digit
When the count is zero there should be an audible beep and the display says End, if that is not possible there should be an audible beep and the display stay at zero
The digits will change with a turn of the wheel the count is entered by pressing the wheel (when the wheel is pressed the light comes on and the count down begins)
When the door is closed the count should continue instantly.
I hadn't thought about setting the count to zero but I suppose that will only happen when the timer has finished.

Is it possible to show the time on the panel? Maybe after the display has said 00:00 for 10 seconds? The clock would revert to a timer once the wheel was turned.

I hope I have been clear enough now, thank you SO MUCH for this.
 

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Thread Starter

TogetherInElectricDreams

Joined Jan 23, 2019
183
Start with what you know. Do you want to reproduce, exactly, what is in the video? Probably not, you want to do something in particular and the video is like it, so tell a story about what it would be like to use what you want to build.

If you want exactly what is in the video, which I must say I don’t fully understand the background on, have you contacted the person who posted it?

Basically, explain the problem to get help with a solution. You know what you want, describe it, then people can help you produce all the other things and build something.

Yaakov, I didn't see your reply but thank you for making it all much clearer. I see what you mean now and DJFantasi has helped with his questions, really appreciate you both. I'm learning with each reply I read, I find it all interesting but it's clearly not somewhere I have natural talent lol! :)

@djsfantasi will certainly be helpful, he could do what is seems like you want in his sleep, or at least while groggy.
 

djsfantasi

Joined Apr 11, 2010
9,156
Thank you so much for your questions and helping be clear about my requirements. I am not sure if you saw the video but I will attach a picture to make it all clearer. Here are my answers
I need to input 2 digits
4 digits in the display but only 2 will change when the wheel is turned, minimum number the wheel can set is 01
Countdown will be 1 second per digit
When the count is zero there should be an audible beep and the display says End, if that is not possible there should be an audible beep and the display stay at zero
The digits will change with a turn of the wheel the count is entered by pressing the wheel (when the wheel is pressed the light comes on and the count down begins)
When the door is closed the count should continue instantly.
I hadn't thought about setting the count to zero but I suppose that will only happen when the timer has finished.

Is it possible to show the time on the panel? Maybe after the display has said 00:00 for 10 seconds? The clock would revert to a timer once the wheel was turned.

I hope I have been clear enough now, thank you SO MUCH for this.
Lol!

Of course you can display the time! But it’s a little more work. Not being prideful, I can make an Arduino brew your coffee in the morning and automatically reply to your emails, while it cleans the cat box, washes the dishes, does the laundry and takes the trash out.

:rolleyes:

I do my best work in the pub, but it’s not always clear. Let me go home and reply to your needs.

Talk to you soon!
 

djsfantasi

Joined Apr 11, 2010
9,156
I love it, project creep already!

The beauty of using a microcontroller is that changes in operation are easily made as long as no new hardware is needed.

Don’t know if an Arduino Nano has a crystal. One is needed to keep accurate time.

Also, you then need some way to set the time.

Bob

Nope, no crystal. That’s why when using an Arduino, I recommend a RTC module. That way the module keeps accurate, battery-backed up time (and date) readily accessible via a library call.

Setting time is easy. No need to add that as a hardware feature. The IDE can set the RTC, which will be valid for months, if not years. (I have a system with the correct time which was set in 2016 and the processor hadn't been powered since 2017 )

I am going to concentrate on the original specs (once I get them defined). We can then worry about feature creep. As you noted, with an Arduino, adding features is more about code than hardware.
 

Thread Starter

TogetherInElectricDreams

Joined Jan 23, 2019
183
I love it, project creep already!

The beauty of using a microcontroller is that changes in operation are easily made as long as no new hardware is needed.

Don’t know if an Arduino Nano has a crystal. One is needed to keep accurate time.

Also, you then need some way to set the time.

Bob

haha! Project Creep, what does that mean? Was it when I suddenly added a little extra to the spec? :-D
 

Thread Starter

TogetherInElectricDreams

Joined Jan 23, 2019
183
Lol!

Of course you can display the time! But it’s a little more work. Not being prideful, I can make an Arduino brew your coffee in the morning and automatically reply to your emails, while it cleans the cat box, washes the dishes, does the laundry and takes the trash out.

:rolleyes:

I do my best work in the pub, but it’s not always clear. Let me go home and reply to your needs.

Talk to you soon!
You know? I might take this project instead...the kid can wait hahaha! Awww! Thanks so much for helping me. If you are happy to explain things I am happy to learn. I sort of understood what you meant about the input but there'd be only one wheel to do everything. My notifications aren't always coming straight through but I'll keep checking back for your reply. :)
 

Thread Starter

TogetherInElectricDreams

Joined Jan 23, 2019
183
Thank you everyone, for being kind and not making me feel like a slo-mo even though I am. I can market your business but I can't power your neon sign lol! I guess everyone has their forte :-D
 

djsfantasi

Joined Apr 11, 2010
9,156
You know? I might take this project instead...the kid can wait hahaha! Awww! Thanks so much for helping me. If you are happy to explain things I am happy to learn. I sort of understood what you meant about the input but there'd be only one wheel to do everything. My notifications aren't always coming straight through but I'll keep checking back for your reply. :)
What I would do with the wheel, is using a microprocessor, read the setting of the wheel (connect one side of the potentiometer to the supply voltage) and map that to a set of numbers you want to display.

The Arduino (and many other microprocessors) have an analog read command. On the Arduino, it returns a number from 0 to 1023, corresponding to the voltage level (you change the input voltage with your “wheel”.)

Arduino C has s map command, so you can easily map the input to any range you want. Let’s say 0 to 59.

Then, I’d extract the two digits from that number to display. I’d also use that number in a loop, to count down on the display.

Just for fun, I write a piece of code, illustrating what I’d do. It’s not complete, it’s not debugged and it won’t compile. But it shows the concepts I’ve been talking about. I even added the door opening interrupt.
 

DNA Robotics

Joined Jun 13, 2014
647
Since the clock is the trickiest part, this is a good place to start.


In the library for that multi-function shield, there is a sample sketch (program) for a count down timer. There are other sample sketches to read input from a potentiometer or a digital encoder wheel. Once you get each part working, you can combine them all to have what you are requesting.

Start by getting Arduino Uno and make some LEDs flash. You will have to do some reading to understand how the programming works. Enjoy the learning experience and sense of accomplishment. Have fun!
 

djsfantasi

Joined Apr 11, 2010
9,156
Since the clock is the trickiest part, this is a good place to start.


In the library for that multi-function shield, there is a sample sketch (program) for a count down timer. There are other sample sketches to read input from a potentiometer or a digital encoder wheel. Once you get each part working, you can combine them all to have what you are requesting.

Start by getting Arduino Uno and make some LEDs flash. You will have to do some reading to understand how the programming works. Enjoy the learning experience and sense of accomplishment. Have fun!
Nice find! Do you have the link to the site where this is found? Is this shield something this guy makes or can it be found elsewhere?

It does have most of what the TS is looking for and may be a simpler solution for him.
 

DNA Robotics

Joined Jun 13, 2014
647
I bought two of those on eBay like this one https://www.ebay.com/i/372382650802?chn=ps

But as we know, they come on the slow boat from China. Since the TS also needs an Arduino Uno, that would be a cheap place to get both. (Get a few Unos in case they are not all good) Otherwise, Amason and Spark Fun are faster.

They have a lot of good stuff on them.

Using an Arduino Multi-function Shield
https://www.mpja.com/download/hackatronics-arduino-multi-function-shield.pdf

Getting Started With the Arduino Multifunction Shield
https://www.electroschematics.com/.../getting-started-with-the-arduino-multifunction-s...

Oct 14, 2018 - Luckily, requisite googling found a “multifunction shield” for the Arduino Uno platform available at a low cost from most internet suppliers.

multi function shield examples - Arduino Learning
arduinolearning.com/code/multi-function-shield-examples.php

multi function shield. Features. 4 digit 7-segment LED display module driven by two serial 74HC595's 4 LED's. 10K potentiometer 3 x push buttons. Piezo buzzer
 
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