Hello there again everyone,
Sorry been busy for a few days. Thank you so much for taking your time.
I note Aldi selling a device purportedly for sterilising your phone( ) but do they actually make UV-C LEDs?
Yeah, it seems they make them. (At least I have found one online and never actually got to see it.) I can send in one of the links if you are interested, or maybe you can correct me if I am wrong about all this.
EEPROM has limited writes so probably wouldn’t be great for storing timing data for this long unless the arduino didn’t shut down in an uncontrolled fashion and thus had time to write to eeprom only on occasions when necessary rather than regularly just in case of loss of power. Of course it only takes one glitch and your counter is back to 0 in this case
I have read about EEPROM and I think you are right. One small glitch would reset my counter or make it useless so I have given up on that part.
What sort of time period do you expect this device to actually exist, not run, but exist?
10,000 hours = 10,000/24 = 417 days, that is over a year continuous operation.
Are you over thinking your project?
A 2 hour a day operation will be 5,000 days or 13.5 years.
You might be better to write the start of operation date on the light.
The other factor is the UV radiation level, it will not be constant up to 10,000 hours operation then cease.
I would be checking the level of radiation at regular times as a calibration measurement to see exactly how your LEDs are working. This will take into account things like power supply performance and enclosure characteristics in one measurement to give an overall performance.
Better than waiting for expiry date.
It would take too much time for the LED power to run out as you have mentioned. And from your previous reply I learnt that LEDs will probably start working because of connection issues. Therefore, I gave up on that part. I think trying out the calibration method you have given me is more useful.
Again, thanks to all of you for taking your time.