Introduction: Time-thief Clock

25 hours in a day? 8 days in a week? Do you

want that?

Have more time to enjoy for yourself, or start a good habit. Yes! You are getting better now! Sounds great?

But, is this realistic? How can you create more time?

How about stealing a minute from every hour? I bet you can’t feel that.

Now you have extra 24 minutes time in a day. Enjoy it!

Sounds cool? Let’s build it!

Step 1: Material List

Here are some of the parts you need:

1. An Arduino board (I’m using Arduino Uno, but other ones should also be ok. Just ensure you have enough output pins!)

2. A 7-segment display (For showing the time as a digital clock. I know there’s another kind of display with a backpack and a clock chip behind that. But the simple one is also ok!)

3. A breadboard. (I suggest you to use a mini one, to save space for a beautiful shell.)

4. 9 resistors (I’m 330 Ohm—500Ohm will all be OK.)

5. Some jumper wires

6. Two tactile switch buttons (Or anything that can work as a button. Maybe a touch sensor? Or something more creative? Imagine it!)

7. Some sockets for the 7-segment display

8. A clamp (optional)

9. Some material you want to make a beautiful shell (I’m still work in progress so I’m just using a simple cardboard box)

10. Your interest and patience! Boom!

Step 2: Circuit Diagram

At first, the most important thing is to

learn how a 7-segment display works.

Here’s a picture of a 7-segment display. As we can see in the picture, there are 12 pins outside that. We numbered it 1-4, A-I.

1-4 pins are digital connections, decided which number should be lit up on the display. A-G pins are controlling different LEDs for each number. F and I pins are lighting the colon between hours and minutes.

A-G pins need to be connected to resistors, then to digital pins on Arduino board. While pin 1-4 can just be connected to digital pins directly. Here’s guide for you.

For pin F and I, we can just connect them to the power source and ground, as the colon will always be lit up at any time!

Be patient! It’s easy to plunge into a wrong place. Remember to use different colors of jumper wires and double check it after place them.

Here’re my circuit pictures. I’m using a small breadboard to save place. If you want to do the same thing with me, you can cut your resistor a little shorter. And it’s so crowded that you may need to arrange the space (just like plunge a resistor and a jumper wire in the same hole). Be careful of this part! If you cut them too short, it’s easy to make an open circuit. Just like me. I spent a whole night to check where goes wrong.

And, you can use some sockets under your display, to hind the circuit.

Step 3: Code

The most difficult part for code is that

this is an inaccurate clock. Code for normal clock won’t work on it. So does a clock chip.

But we can still learn something from a normal clock code using on a display.

To be brief, the code can be separated into three parts. The first one is counting the time. The second one is to decide which LED will be lit up while showing a particular number. And the third one decided the number to show on the display.

Actually, I still have some problem using the “Display” statement. I’m using a complex calculation to describe time, cause every time I change a way to calculate, it will say they can’t find a display before. If who can tell me what problem is, I’ll say thank you (for ten times!) to you!

Step 4: Make It Better!

Now I just figure out how to show 59

minutes in an hour. And I’m doing user interview now. Some people what to adjust how many minutes they can steal in an hour. Some people want to use the gift concept instead of the thief one. And some, what to choose when will they get a bonus time. I’m still testing which concept is more acceptable and trying to figure out the code work for that. And I’ll 3D print a beautiful shell for it. The new project will come soon! Boom!