Please bear with me as I'm just in the early stages of planning this as part of a university project,
I am trying to find a method of connecting multiple RFID readers to the Raspberry Pi, however In addition, I would also need a method of detecting which reader was activated.
I was hoping to use the following readers, http://www.ebay.co.uk/itm/170976906170
, simply because I already have one. These readers are very simple to use, they work completely plug-and-play on the Raspi and upon scanning a tag/card, they will simply input the string of the token into the active program (as if it was just a keyboard/generic input device)
The way in which I was kind of thinking of detecting which device was activated was to simply add a prefix to the input string, then I could simply parse the first couple of digits of this input and work out which reader it came from. This is just a vague idea at the minute and to be honest, I would have no idea where to start to identify even which USB port is being used.
I am completely open to using 'component' RFID Wiegand readers as I understand many people have done successfully, however (and this is where my knowledge gets VERY shaky) as I understand it, You would do this using the I2C bus of the Pi? and there is only one input for this?
My language of choice would be C++ or Python, however I'm happy to learn what I have to!
My budget is fairly low and so I would ideally like to stick to readily available cheap readers such as the one I linked to earlier or, if a wiegand reader, something like the following http://www.ebay.co.uk/itm/251211288263
Absolutely any help you guys would be able to offer would be much appreciated, as I say, this is very much just my initial thoughts on the project and I understand I am going to have to put a lot more thought into it yet.
Thanks in anticipation,