Arduino suitability

I’m hoping to develop a fairly straightforward project. I’m looking for advice on whether Arduino is a suitable platform for the job.Some time ago I used to be able to program in C and can understand many of the examples provided here. I’ve done some electronic projects in the past.

The project is roughly:

  • Countdown timer with LCD or LED display showing MM:SS on the countdown. After countdown completes the display will show ‘stopwatch’ time.
  • At precise predetermined intervals activate a car horn for either 250milli-seconds or 1 second (e.g. sound horn for 250ms at 8mins to go, 1 second at 1 mins to go, 25ms at 30 seconds to go, 1second at 1 minute after stopwatch timer begins).
  • provide a push-to-make button to allow the operator to sound horn on an as-needed basis.
  • Provide a reset button to re-start the sequence.

Car horn will operate on a 12v battery and I’d like to package the whole thing up to work off a single 12v battery in a sealed waterproof unit.

The questions I have:

  1. Is Arduino a suitable platform to deliver such a project?
  2. Would an LCD or LED 7-segment display be easier to use (i.e. program or wire in)?
  3. Where would the key problem areas lie? (I’ve read about stable supply voltage being problematic.)
  4. Any general advice before embarking down the Arduino route?



that is easily doable… I would use an LCD unless you like to wire a lot. Serial LCD’s are asier to wire than parallel LCD’s. Other than that you just need to connect a switch (see button tutorial) and a relay or high-current transistor for the Car horn (Google arduino + relay).
You will also need a power supply or battery capable of putting out the current for the horn: something like 3@ at 12V.

When you start to build this, just do it one piece at a a time:

  • get LCD working, see if you can print messages to it;
  • get button working- can you print messages to LCD in response to button?
  • get horn working: can you control the horn on-off with code?

Once the answers to all these questions are yes, you can integrate the final code to make it all do what you want.


The Arduino is perfect for that.

I’d use a 12v relay for the horn. Fairly simple.

No reason to spend extra on a serial LCD.
It only uses 6 pins (3 with a technique I developed).

Also if you want 7 segment displays you’d be wanting to grab a MAX7219 chip.
Makes it easier to work with them. One chip will run up to 8 digits.