I have only recently started reading about arduino microcontrollers and I have a couple of questions that I hope that you can help me with...
First let me explain what I want to accomplish and then please let me know if my assumptions/beliefs are correct.
Once a month at my local sportsman's club we have a steel plate pistol shoot. We shoot five steel plates with either a 22 rimfire pistol (small target impact), or a larger centerfire pistol (for example a .45 with a much larger impact). The steel plates hang from steel chains and are labeled 1-5 (not necessarily in order). We are then timed. Time starts when we hit plate 1 and ends when we hit plate 5. Currently we are using a hand held stopwatch, so the times differ from one timer to another. We are allowed to load 6 bullets so we have the chance to try one target again if we miss, but they must follow order 1-2-3-4-5... If you miss target 3 you must continue to fire at it until it is hit or you run out of shells.
We also run a head to head competition where there are two groups of 5 targets as listed above. Both shooters upon hearing the “FIRE” command try to do their five targets in order faster than their opponent. The first one to hit target 5 in order wins.
What I would like to do is mount an accelerometer on the back of each target and have an arduino microcontroller report how long it takes to hit all five targets. Basically when the first target is hit time would start, and when the last target is hit time would stop. It would also be nice to have an indicator above each target to signal a hit. I plan on using a bluetooth module to send the information to my android phone. I would also like to see the times from target 1 to target 2, 2-3, etc... It must also be able to verify that the targets were hit in order. It would be nice if I could switch between 5 target individual to 10 target head to head mode. In head to head mode time would start when a beep or sound is given to the shooters. The timing in head to head isn't as important as who hits target 5 first and hits it in order.
Does this sound reasonable? Do I need to get an arduino mega to have enough inputs and outputs for what I want to accomplish? Will a MMA7361 or an ADXL345 accelerometer sense the impact of a bullet striking a steel plate? Am I nuts?
My wife is a java developer so she should be able to help me with the android side of things. I remember a little C from college ( I also remember a little Fortran77, so it has been awhile...) so I hope through reading a couple of books and looking at examples I can find my way through the programming.
Any comments and ideas would be greatly appreciated. Thanks.