Project guidance needed on: Clock - Stopwatch - Stopwatch/Timer

Projects General Guidance
1

Hi all,

I'd be interested in doing a clock-stopwatch-stopwatch/timer project.

The clock has 3 modes:

  • Basic clock
  • Stopwatch
  • Stopwatch/Timer

The controlling and adjusting is done by 4 buttons.
It has a screen (LED or OLED; I have no idea what would be the most suitable) which displays the numbers.
It should have a small speaker for the timer, but this is not necessary.

1. Basic clock

The first one is just a basic clock. There would be four buttons to control the clock.
A mode button, an up button, a down button and an enter button.

Controls

[MODE]
Pressing the mode button toggles b/w the clock, timer and timer/countdown modes.
By pressing and holding down the mode button you could adjust the time.
When adjusting the time and the mode button is pressed it toggles b/w hours, mins and secs.

[UP/DOWN]
These buttons adjust the selected number (eg. mins), decrementing or incrementing.

[ENTER]
When the time has been adjusted to correct values, it can be set by pressing the enter button.

2. Stopwatch

Stopwatch works like a normal stopwatch. You can start it, stop it and reset it.
When started it displays mm'ss'', when minutes becomes greater than 60 the display
changes to %H:%M:%S.

Controls

[ENTER]
Toggles start/stop of the stopwatch.

[MODE] + [ENTER]
Resets the stopwatch.

3. Stopwatch/Timer

Third mode would be a combination of a stopwatch and a timer.
The stopwatch and timer would be displayed adjacent to or on top of each other.

When the timer is adjusted (greater than zero) and the user starts the timer, the stopwatch
starts counting up and the timer counts down. When the timer reaches zero it continues from
its initial value whilst the stopwatch continues counting up. (This is where the speaker would be handy
to alert the user that the countdown has been reached.)

Controls

If the timer is not set when entering this mode it should automatically put the user to adjusting the
timer's seconds (this is indicated by the blinking numbers).

[MODE] Held down
When this mode is not running and the user is not adjusting the timer, when held down it puts
the user to adjust the seconds of the timer.

[MODE]
Toggles b/w min and sec for the timer.

[UP/DOWN]
Increment or decrement the timer's values for minutes and seconds.

[ENTER]
When adjusting the timer and pushed the set values are applied.
If the timer is set and enter is pushed it toggles start/stop of the stopwatch and the timer.

I would like to know what parts and what Arduino board I need for this project. Is too difficult for
a first project? What should I take into consideration when planning this further, etc...

Any help I can get is welcome!

Here's a quick "proto" of the clock mode:

This clock is meant to be used in a dark room for developing film and prints. I have had no problelms
with red leds in use when I have developed prints. So, maybe a red LED screen???

I haven't done any projects or hacking on Arduino nor on any other microprocessors.
I have programmed a bit in Java and Ruby, so I think I could somehow manage the programming,
but I really don't know anything about microprocessors, I'm keen to learn though :wink:

Peace,
juhoh

2

Start Here -

Later you can add the sensor if you like and time races with it -

Add an amplifier like this -

And it sounds like this -

Duane B

rcarduino.blogspot.com

3

You can get safe light filter material that could be placed over a display. Then a nice high contrast display would work.

For a darkroom timer you should consider adding a relay to turn your enlarger on and off.

4

Maybe use a display like this?

You have your modes & buttons defined, well, so the time tracking coding would be straightforward.
Looks to have an almost SPI like interface, so lots of IO pins are not needed.