Protecting an atmega644p circuit

Dear all,

I would like to ask a couple of questions regarding protection of my circuit, which is using Atmega644p, couple of buttons, RTC, display and a 100 WS1212B LEDs.
The whole circuit is powered by a brick 5V 40W DC power supply, schematic attached below.
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For now, I have no protection applied - I rely solely on the power supply.
Questions:

  1. is this a good idea in general?
  2. should I apply at least some protection for the IC, and if yes, which?
  3. should I apply at least some protection for the LEDs, and if yes, which?

Really don't know what is the "standard" level of protection for this kind of circuits.

Thanks,

Ferso

Protection against what?

...R

I am talking about e.g:

  1. reverse polarity protection
  2. overcurrent protection

How are you connecting your power supply to the Arduino? How could reverse polarity occur?

If you want to protect against reverse polarity then you could fit a diode between the connection point to your power supply and the Arduino.

By over-current protection I assume you are referring to something connected to an I/O pin drawing too much current and damaging the microprocessor. Again it seems essential to ask what are the circumstances in which this could occur? There are probably different solutions for different cases.

...R

  1. Use a Schottky diode or a relay.
  2. Current where?

@Robin
Reverse polarity should not occur in this case at all, DC jack can be plugged in one way and one way only - my question in this case is more like should I even consider this, when there is very low probability of this event occuring?

By over-current protection I assume you are referring to something connected to an I/O pin drawing too much current and damaging the microprocessor. - yes exactly. LEDs are powered by the brick power supply, again more of a philosophical question, cant think of a specific reason why this should occur.

One more thing that comes to my mind is overvoltage protection - if someone accidentally plugs in lets say a 12V power supply, to protect the LEDs and IC for example with crowbar circuit?

ferso:
@Robin
Reverse polarity should not occur in this case at all, DC jack can be plugged in one way and one way only - my question in this case is more like should I even consider this, when there is very low probability of this event occuring?

By over-current protection I assume you are referring to something connected to an I/O pin drawing too much current and damaging the microprocessor. - yes exactly. LEDs are powered by the brick power supply, again more of a philosophical question, cant think of a specific reason why this should occur.

I don't think there is any value in contemplating unlikely events - particularly if no lives are at risk. In many cases it is cheaper to have a spare product than to implement the precautions that would render the spare unnecessary.

Or, put another way, if it's not worthwhile making a spare then the problem has very little value.

One more thing that comes to my mind is overvoltage protection - if someone accidentally plugs in lets say a 12V power supply, to protect the LEDs and IC for example with crowbar circuit?

This risk probably presents a slightly higher probability. But, again, how likely is it? Who, apart from you, is likely to be choosing a power supply for the project? In what circumstances might they choose the wrong power supply?

Can you put a label marked "Arduino" (or something more useful) on the cable for the Arduino close to the end that connects to the Arduino and explain that this is the ONLY cable to be connected to it?

It's possible to change the plug for something that is unlikely to be on other equipment - but that's a lot of trouble,

...R

Thank you, I agree with what you are saying, just wasnt sure.

Have a good one