Hi, I am currently designing a product,the device must detect a specific object(on no axis & must be battletyess eg. tag /receiver) when it reaches within 30cm of the device without line of sight. I would like to inquire as to what IC would best suit this application or even what technolodgy(nfc,rfid,ultrasound, etc)?
Thank you

 

It would help if we knew some details about the object that you are trying to detect. e.g. if it is transparent, optics will not work. If it's surface is black, IR may not work. If it's surface is soft, ultrasonics would not be a good choice.
Regards,
Keith

 

hey thanks Kieth,
the object is a hand but the sensor must only detect the hand rather than a proximity device detecting any object,for this reason i was thinking nfc as the tag would specific to the hand,also this would not need power but im not sure what chip to use.
thanks,
shane

 

How would you attach the tag to the hand? Would it be temporary or permanent?
Stick-on NFC tags are small and readily available and quite inexpensive. RFI tags come in a number of sizes and frequencies but are generally more expensive. Readers are readily available for both but will depend on what you want to do with the information. You can use it to simply open a lock, log time data or make payments.The reader can be self contained, interfaced to a computer or run on a smart phone.
Keith

 

thanks Kieth,
i was thinking of inplanting it in a wristband,I want the reader to output a HIGH to a piezo when it detects the hand within 30cm,would i need a microconntrroller to opperate this or might i be able to just tie the output of the reader to the piezo as its a simple opperation?also can you vary the detection distance/sensitivety of an NFC reader? The device would have to e self contained
thanks again,
shane

 

There are many different types available. Maybe something like this would do the job:
Keith.

https://www.aliexpress.com/item/329...earchweb0_0,searchweb201602_,searchweb201603_

 

I don't see how this can be done without a power source, unless the detected object is guaranteed to be a transmitter.

 

I don't see how this can be done without a power source, unless the detected object is guaranteed to be a transmitter.

there would be a power source on the device end but not on the tag/hand end
thanks,
shane

 

thanks kieth,
The issue im having at the moment is keeping the reader & included circuitry all as small as possible, i need to either design an NFC reader small enough (aprox:40mm x 20mm x 10mm)-including an nfc IC, airpod style batery, piezo and antenna- or find a pre-dessigned module. firstly Im very confused as to what IC to use and secondly would i need a micro controller IC. The antena calabration I am unfarmilliar with.
thanks,
shane