How long will a mega-168 last, used continuously?

If an atmega168 is programmed to perform a specific duty, or with a specific sketch, then, with power connected, set into operation collecting data, or whatever duty it is set to perform, about how long will it continue operate before it wears out?

What if it was set up as a timer, then just left alone to time away at will, how long do you think it would stick around and continue with the timing?

On the other hand, how many times can one be started and stopped, then reprogrammed, then started it up again?

Capacitors fail over time, but semiconductors are quite hardy. Unless you’re cooking and freezing the device all the time, expect the chip to operate just fine for many years.

However, there are multiple parts of the chip to consider. Almost all of the logic, and the RAM, should never wear out. The read-write cycles of the PROGMEM area are a lot more limited: if you expected to reload the sketch some 10000 times, I’d worry about the PROGMEM storage to wear out. And most likely to fail is the EEPROM: it is much more hardy than the PROGMEM, but also way more likely that a sketch might try reprogramming it too often.

But if you don’t reflash or rewrite these memories needlessly, or do something silly like run way too much current through an i/o pin, the chip is easily going to outlast your interest in it.

The flash memory (where you write when you program the device) is rated at 10,000 write cycles, so it can be reprogrammed 10k times.

If the device is properly cared for (ESD protection, heat protection, etc) it should operate more or less indefinitely - as long as you would expect any other piece of electronic gear to last, anyway.

-j

Thank you.