i was wondering how to connect 6 id-12 rfid readers to an arduino. i think soft serial needs to be used. i am still unfamiliar with arduino and am using these rfid sensors for a university project. need urgent help.
thanks
i was wondering how to connect 6 id-12 rfid readers to an arduino. i think soft serial needs to be used.
You might be able to use NewSoftSerial to read all of the RFID readers. The problem will be that only one instance of NewSoftSerial can be active at a given time, and only the active instance can receive serial data. If you have 6 instances, and instance 2 is active, while the reader connected to instance 5 sees a card, and spits out serial data, that data will be lost.
If you don't need to know which reader read the card, you could connect all of them to one serial port (hardware or software) and see all the data from any reader on that port. As long as two readers aren't sending data at once, you'd be OK. The time required to transmit the tag data is pretty small, so this might not be a problem.
If you ORd (or ANDed -- not sure how the ID-2 modules work) the serial buses together and fed them into the serial input as PaulS suggests, you could ALSO feed the lines separately to 6 digital input pins and have some logic to look for which of the lines changes state when the RFID read is seen. This would allow you to identify which of the readers is reading the tag.
i need each rfid reader to read at the same time. its is a spelling game that i am creating where a block is placed over an rfid sensor with a tag and each of those sensors will read if the correct block has been placed ontop. and when the correct block has a led will light up. this could be done in a sequence however i would prefer if they all worked so the child could randomly place blocks anywhere. and the word be spelt.
is it possible for some code to be written as i still do not understand?
i need each rfid reader to read at the same time.
No you don't you just said:-
where a block is placed over an rfid sensor with a tag
So only one is going to be placed a any one time. You will not get any simultaneous reads.
I would have a multiplexer scanning the inputs into the serial line. When it detected a logic zero it would keep that input selected for the time it takes to transmit one ID message and then continue scanning.
Can you change the readers to Weagand output?, it would be easier if you could.
im not sure if u can change the output. at the moment all that i am trying to achieve is to connect all 6 rfid readers to the arduino. and have each reader read a rfid tag
thats all that i need to achieve thus far.
is this possible and can anyone direct me with some code that will make this possible
mastrolorito:
a spelling game that i am creating where a block is placed over an rfid sensor with a tag and each of those sensors will read if the correct block has been placed ontop.
I'm not sure if ID-12s have a reliable "tag present" indicator. With most RFID sensors I've met with, what you will know is the most recent tag that has been read, but not necessarily if the tag is still there. So if a block is placed, or slid past a position, there is no certainty later on, that it has not been removed. I suspect you will also want simple IR sensor to know that a block is or isn't placed at a given location -- this would let you know if a block is placed, but later removed.
To sense what blocks are where at a given moment with RFID would require some non-standard functionality in the reader -- maybe allow them to be polled to ask what tag(s) are in range on-demand. I think that a function like this could be incorporated into the open source SnifferNano:
that is simular to the id-12. and the refresh rate knowing that there are tags still present are the problem. the sensor does not know if it has been removed. So placing a block is perfect. it will only need to read when a different tag is placed.
There is a simular piece of code from bildr
with this i would like to know how to connect 6
can anyone alter his code for 6 rfid sensors using softserial?
is it possible
thats all that i need to achieve thus far.
It might seem to you to be an easy and trivial thing but reading six serial streams is actually very difficult without hardware support. I don't think there is enough processing power in the arduino to do this in the way you would want. I think you need extra hardware support of one kind or the other.
mastrolorito:
can anyone alter his code for 6 rfid sensors using softserial?
is it possible
Please read carefully here NewSoftSerial | Arduiniana
under "Using Multiple Instances". Here it says "you can have as many devices connected as resource constraints allow, as long as you only use one of them at a time." This means that reading from 6 rfid sensors at the same time is not possible.
You will have to either use two Megas -- which have 4 hardware serial ports each -- or dream up the electronics necessary to multiplex six sensors together on the same serial bus -- which wouldn't be that hard.