No paper question

[Christian Rowe]

Hello, 

I have some questions about the setup. If the printer runs out of paper while printing or no paper is left, does the queue pause or restart? Or is their no functionality to detect this? If any other errors occur for the printer does the queue on the server pause or something? I am very interested in your project and your awesome work you have done for a business idea. Any help and answers would be greatly appreciated!

Christian

[James Adam]

Hi Christian,

On 8 Apr 2013, at 05:42, Christian Rowe <c.r...@yahoo.com> wrote:
> I have some questions about the setup. If the printer runs out of paper while printing or no paper is left, does the queue pause or restart? Or is their no functionality to detect this? If any other errors occur for the printer does the queue on the server pause or something? I am very interested in your project and your awesome work you have done for a business idea. Any help and answers would be greatly appreciated!

At the moment, there's nothing in the Arduino sketch that monitors for the printer being out of paper. This means that it would be quite possible for the Arduino to continue consuming data from the queue without successfully printing it. To be honest, I'm not sure if it would be possible to fit the extra logic into the remaining code space on the Arduino, but it's certainly something someone could try.

Another factor which is somewhat relevant: once the printer "client unit" (be it Arduino, Raspberry Pi or anything else) has made a request to which the server *can* respond with data, that is removed from the queue. So, at the moment, it isn't possible for a "client unit" to ask for something to be retransmitted. I had wondered about requiring the Arduino to send a confirmation post back to the server, but as above, code size constraints came into play. I had also thought about adding a "reprint" mechanism on the server itself, to allow users to trigger reprinting of specific data, but I suspect that isn't going to address your need either.

So, in a nutshell, no, for two reasons: one, that the Arduino is already approach it's limits, and two, the server doesn't support any kind of client-driven reprint-on-error functionality. Neither would be impossible (or necessarily even that hard) to add, but I don't think it's something I plan to work on in the near future. GitHub pull requests are always welcome!

Hope that helps,

- James