user11529: Would it be possible to delete questions that have no reply from the OP at least a few months or user is inactive and there are no good and useful answers.
There are quite a lot of questions that should be deleted because the OP has vanished that just clutter arduino.stackexchange.
For ex: NRF24 module - how to program arduino so that it is able to listen to 2 pipes

user6936: I would say some caution is required. Just because the OP has vanished, it does not mean that the question is redundant/useless. I Just remember what I heard from a lecturer back at college, many moons ago: 

If you have a question, but are too scared to ask it, for fear of looking the fool, then fear not. If you have thought of that question, then it is very likely that someone else has either already thought of it, and wants to ask it, or will do.

So, taking the example that you have just closed. The question may be a little unclear, due to the OP's possible poor command of the English language. It may, also, be unanswered, however, that does not mean that there is no answer in the post. In fact there are two comments, which offer short, and not in-depth, answers.
It is not the fault of the OP that the question does not have an actual answer as a posted answer. Many times one can see questions, with good answers posted as comments, for the shear quickness of getting an answer up there... The answerer may not be able to find the time to craft a perfectly worded answer, so just to get the OP on their way, the solution is posted as a comment. Often the writer of a very good comment is asked to turn that in to a answer, so that it may be accepted.
So, in short, closing a question that has answers in the comment, I feel, is a little short sighted, as someone else is probably thinking the same thing, and those comments could just give them the help that they require. I know that they have helped me in the past. 
Obviously, some questions are so awful that they deserve to be scrapped, however, in this cited case, I don't believe that it is. 
Also, these awful questions will generally get closed through the use of close votes. If no one has voted to close it, then it is probably not a good idea to take an executive decision to close it. Let the democracy vote the questions. As the docs say, a moderator generally has very little to do, until issues are raised. There is no need to go looking for work ;-) 
Instead of closing the question, why not turn the comments into answers?

user220: Simply put, if they can't be answered, they should've been closed already. Too broad is applicable if they don't have enough information in their question to narrow it down to a specific solution (you end up getting a lot of very scattered answers).
So, close questions if they can't be answered. They'll get deleted after some time automatically.

11529: <p>Would it be possible to delete questions that have no reply from the OP at least a few months or user is inactive and there are no good and useful answers.</p>

<p>There are quite a lot of questions that should be deleted because the OP has vanished that just clutter arduino.stackexchange.</p>

<p>For ex: <a href="https://arduino.stackexchange.com/questions/7902/nrf24-module-how-to-program-arduino-so-that-it-is-able-to-listen-to-2-pipes">NRF24 module - how to program arduino so that it is able to listen to 2 pipes</a></p>
 6936: <p>I would say some caution is required. Just because the OP has vanished, it does not mean that the question is redundant/useless. I Just remember what I heard from a lecturer back at college, many moons ago: </p>

<blockquote>
  <p>If you have a question, but are too scared to ask it, for fear of looking the fool, then fear not. If you have thought of that question, then it is very likely that someone else has either already thought of it, and wants to ask it, or will do.</p>
</blockquote>

<p>So, taking the example that you have just closed. The question may be a little unclear, due to the OP's possible poor command of the English language. It may, also, be unanswered, however, that does not mean that there is <em>no answer</em> in the post. In fact there are two comments, which offer short, and not in-depth, answers.</p>

<p>It is not the fault of the OP that the question does not have an actual answer as a posted answer. Many times one can see questions, with good answers posted as comments, for the shear quickness of getting an answer up there... The answerer may not be able to find the time to craft a perfectly worded answer, so just to get the OP on their way, the solution is posted as a comment. Often the writer of a very good comment is asked to turn that in to a answer, so that it may be accepted.</p>

<p>So, in short, closing a question that has answers in the comment, I feel, is a little short sighted, as someone else is probably thinking the same thing, and those comments could just give them the help that they require. I know that they have helped me in the past. </p>

<p>Obviously, some questions are so awful that they deserve to be scrapped, however, in this cited case, I don't believe that it is. </p>

<p>Also, these awful questions will generally get closed through the use of close votes. If no one has voted to close it, then it is probably not a good idea to take an executive decision to close it. Let the democracy vote the questions. As the docs say, a moderator generally has very little to do, until issues are raised. There is no need to go looking for work ;-) </p>

<p>Instead of closing the question, why not turn the comments into answers?</p>
 220: <p>Simply put, if they can't be answered, they should've been closed already. Too broad is applicable if they don't have enough information in their question to narrow it down to a specific solution (you end up getting a lot of very scattered answers).</p>

<p>So, close questions if they can't be answered. They'll get deleted after some time automatically.</p>
