How Hard Will This Be? Stopwatch + Button Counter + Datalogging

I work at an ornamental plant nursery. Here we have something akin to an assembly line where plants are produced. People stand at stations and complete repetetive tasks in order to create the plants that we grow and sell. Our objective is to get better at tracking individual output during this process. What I want to do is create a device that is present at each work station. This device will combine a stopwatch with a push-button counter, and have the Arduino log the values for each. The logs will then be exported for use in a spreadsheet.

Here's a rough sketch (not a technical diagram) of what I imagine the device will look like, along with some notes on functionality: http://imgur.com/HsdVV0H

And here's how I envision the device operating:

  • There's a master on / off switch. Turning the device off then on again will reset all counters.
  • Pressing the start button gets the timer running.
  • Pressing the stop button pauses the timer. Pressing start again resumes the timer. The stop button will also trigger a red LED to pulse to alert workers that the clock is not running.
  • Pressing the counter button will cause the counter display to go up in increments of one. Pressing the counter button while the device is in stop mode will not affect the counter.
  • At the very least, total elapsed time and the number of button presses will be logged by the Arduino for use in spreadsheets elsewhere.

On a scale of 1 (easy) to 10 (what was I thinking?), how difficult do you guys think this will be? Have you encountered any other similar projects I can look to for guidance? Thanks in advance for the help!

Fairly easy, hardware-wise. I have a card that you can easily attach buttons & LEDs to, it has a battery-backed realtime clock and an SD card already.
Codewise, most of it's pretty straightforward, reading the presses, controlling the LEDs, making I2C calls to get a time. Might have to get some help for writing the data to SD card.

The processor is overkill; I haven't made a similar collection of parts with a '328P, but it'd be easy to roll the design and replace the '1284P with a '328P.
http://www.crossroadsfencing.com/BobuinoRev17/
Shown with off-board FTDI module for programming. Onboard FTDI module is also available.
At the end of the day, round up the SD cards, download the data, and plug them all in again the next day for data capture.

Screw terminals are also available if you don't want to solder to the board. An LED and its current limit resistor can be mounted in the prototype area.