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I am designing an automation system for my research project and planning on using Arduino Uno to do the same. The program is to execute simple instructions based on few input parameters and does not need large computational powers. It is estimated it would take 26 minutes to run the program (26-minute cycle*) and it is expected that it would take anywhere from 3 weeks to 2 months to complete the project (1160 - 3300 cycles before reboot)

My question is as follows:

  1. Is the Arduino Uno capable of surviving the extended service expectancy and execute the program correctly?
  2. What is the influence of small voltage fluctuations on the endurance of electronics on the board?
  3. Is a heat sink needed for this application? How to determine the power draw to choose heat sink size?
  4. Is there any fatigue rating for the cyclic running of the program?

I am planning to power the entire system via a regulated 12V 600-watt battery bank and this bank would be periodically recharged.

*By cycle duration I mean the real word time required for completion of one batch. It is estimated that it's required to complete 1160-3300 cycles/batches for the research

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    Can your application tolerate the MCU resetting via the use of a watchdog timer? – Sacha Apr 14 at 17:22
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Is the Arduino Uno capable of surviving the extended service expectancy and execute the program correctly?

Yes, it is. Though your program and wiring needs to be stable and correct.

What is the influence of small voltage fluctuations on the endurance of electronics on the board?

Depends on what you call small. As long as you don't enter the brown-out region (where the voltage is so low, that the Arduino goes into reset for safety) or giving a too high voltage to it (See the specifications for that), you should be fine.

Is a heat sink needed for this application? How to determine the power draw to choose heat sink size?

The power draw of the Arduino depends on what you are doing with it. The best way would be to just measure the current of your application. Then you get the power by multiplying current and voltage. Normally you don't need a heatsink with an Arduino. The only part, that can get hot, is the linear voltage regulator. Depending on what you are interfacing with the Arduino, you might need to put a small heat sink on that (12V is a bit on the high side of input voltage for the regulator. It will dissipate the excess 7V as heat, so 7V multiplied by the used current). The microcontroller on the Arduino will not get hot (unless you are doing something terribly wrong).

And you should make sure, that the current for extra peripherals in your project doesn't flow through the Arduino, since that will place an extra burden on the voltage regulator. It should flow past it (means you connect them in parallel to the voltage source).

Is there any fatigue rating for the cyclic running of the program?

No, not really. I think the flash memory (where the program is stored) has a data retention failure rate of less then 1ppm (parts per million) over 20 years. So the program will not be lost, until you plan to run your application a hundret years. Also there is no read limit on the flash memory, only a write limit.

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  • Since the Arduino itself uses a linear regulator, the OP might get nearly twice as much work out of their 12V battery with a switching power supply (even if only stepping down to 6 or 7V to feed the input side of the linear regulator, not bypassing it with a 5V switcher.) I'm assuming the Arduino draws enough current to make an efficient SMPS possible, and the linear regulator only needs a volt or two of dropout range. – Peter Cordes Apr 15 at 0:05
  • Connecting up their batteries in parallel instead of series to form a 6V bank with twice the mAh capacity would be good in theory, but only if they don't droop much below 6V as they discharge. (I don't know what kind of low-dropout linear regulator Arduino Uno uses.) If the battery geometry allows it, 9V or 8V that can droop down to 6V would probably be good. – Peter Cordes Apr 15 at 0:09
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    You are right with your first comment, though I didn't talk about it in my answer, since the OP didn't ask about the regulator or power supply. For the second comment: It is correct, but we don't know, if the OP uses individual batteries, which would be able to form a 6V bank. He didn't specify what power bank he uses. Only that its 12V – chrisl Apr 15 at 6:41
  • Yeah, I only mentioned it in case it was possible. Thought you might want to mention something in your answer about selecting a DC->DC converter IC to avoid wasting half the energy in your batteries if that's worth the trouble, and what the minimum dropout for an arduino's linear regulator is, but if not then at least it's in comments. – Peter Cordes Apr 15 at 6:55
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I see no problems in that. Given the program you write is stable and correct, the Arduino UNO will certainly work without any problems for months. It has an integrated voltage regulator, so you can attach a 12V battery directly and it automatically regulates voltage changes. The CPU and/or flash do not have any "fatigue" problems as long as the program is only read or executed. The program flash has a limited number of write cycles, but that also is far beyond where you'll get problems.

Where I do see a problem is in your use case. You seem to be doing quite complex mathematics with quite a lot of data, when one cycle takes 26 Minutes. You might not have enough RAM on the UNO to do this. It has only 2.5k (that is around 2500 bytes) of RAM. Where do you store the results?

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    It's actually 2 K of RAM. – Edgar Bonet Apr 14 at 17:09
  • @PFM Kindly refer to the edit in the question clarifying the run time. – Atul DCT Apr 14 at 17:54
  • How much data do you collect per cycle? And how do you intend to store that data (copy it to a PC?) – PMF Apr 14 at 17:56
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I have Arduino here powered over year long, still working (running the same loop() again and again) without a glitch and it is not even hand-temperature hot in my living room - I expect it to run flawlessly for lot more years, until I will switch it off :)

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