Need help with RFID circuit.

Thread Starter


Joined Jun 15, 2021
I am looking to create some hardware to solve a unique home situation. I have some hobbyist circuit design experience, but only rudimentary knowledge of RFID. I am looking to make some proof of concept hardware for this. Without going into detail about the final situation, I am looking for some guidance on the logic and design. I often reuse things I create for different things after the fact, so I would like it to be scalable as possible. If/when the basics are deemed feasible, I would like to finalize and implement the proof of concept into hardware. Depending on what's all involved with those last 2 pieces, I am willing to pay for assistance in the final stages.

From a proof of concept standpoint, I am looking to track the presence and state of some items.
Originally there was only two possible states, so I was considering toggling two RFID circuits on each tag via switch. Since I have since came up with a third state, and for future scalability, it seems logical to just use the data fields for this instead (If feasible). This state needs to be determined outside of this circuit and without reader being present, as such I think avoiding writing this data to the tag would be preferred. Assuming the number of states are finite, and reasonably limited, I would like to toggle via external switch/switches.

1) I am looking for the tag to be passive if at all possible, without need for batteries.
2) The tag will only need about a 5 or 10 ft range, with none, or only minor interference.
3) System needs to detect multiple tags and states.

Concept circuit:
1) 2 tags with 2, possibly up to 4 states, controlled by external switch(es) or dip.
2) Reader will need to verify both tags are present and functioning, a determine it's state.
3) Display (LCD, or simply LED's will suffice) if each tag is undetectable, or it's state. (STATE1, STATE2, etc) possibly led display of red for undetectable, yellow for state1, and green for state 2 for each of the two tags.

I am not set on any of the above, so I am open to thoughts and suggestions, without going to much into the actual scenario.

Thanks in advance.