OK, OK, you guys have convinced me! I'll crack this nut with a sledge hammer, and finish it this year, if you'll help. Be gentle. It's my first Arduino. I've found the perfect solution -- the "Trinket." It's very small board (0.6" x 1.2") designed with headers so that it can be installed as a through-hole component. It has all the GPIO I need (5), and the cost is only $7.
In the schematic above, pressing S1 starts a 1-shot timer, turns on the LED, and outputs a short pulse on PB0. Unless S1 is pressed to abort the timer, at the end of the 1-shot period the timer is reset (or just stopped), the LED is turned off, and another short pulse is output from PB0. But if S1 is pressed during a 1-shot period, timing is terminated immediately, the LED turned off, and another short pulse is output on PB0.
The period of the 1-shot timer is stored in EEPROM in a variable having a decimal value of 1 to 8, which is the 1-shot period in units of 30 seconds. At startup this value is retrieved from EEPROM. A subroutine to be added later allows the 1-shot period to be customized by counting 1 to 8 presses of switch S2 when the timer is not active. This is referred to as "calibration" While a calibration is in progress, input from switch S1 is ignored. (As you can see, if the discrete component circuit is going to be replaced by a processor, let's make the most of the additional capability.)
The switches will be typical snap-action PCB switches, so inputs can be anything from a hundred milliseconds to several seconds, and debounce is probably necessary. I can live with whatever timing accuracy the internal clock gives us.
I've ordered a couple of Trinkets, and I have downloaded something called Arduino 1.8.4 (I thought I was downloading Arduino IDE). I get a warning that my Windows Firewall has blocked some features of Java. Can someone tell me what additional tools and/or software I will need to become as proficient as one of those primary school kids. I may try to lure one of those kids over with an ice cream cone to program this thing. Any help to get me setup will be appreciated. Once I get any kind of basic program that can be loaded with the boot loader, I can experiment with it by trial and error. Does the Arduino IDE include an editor that provides any help with syntax errors, etc?
okasional