Suggestions for Continuous Presence Detection?

Qwiic System
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@TS-Russell I just realized that the Qwiic RFID Reader is not the proper device that I need as it does not support continuous presence detection which is a must for my setup. I read in another thread (can’t find it any more) that you (?) suggested to use the SparkFun Simultaneous RFID Reader - M7E Hecto if continuous presence detection is required but that is not an option for our product (price too high).

I chose the RFID approach first because I plan to have several controllers and holsters and therefore would like to identify via the RFID tag if the controller is in its proper holster or in a wrong one.. the following approaches would of course remove that option..

I wonder if you have other suggestions or what you think about these ideas:

Solve the presence detection with something like:

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I was just wondering, could I use those 2 devices together?

SparkFun Qwiic GPIO

to connect to Qwiic and then attach the

SparkFun Photo Interrupter Breakout Board - GP1A57HRJ00F

there?

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Yes, you could.

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Hi @YellowDog and thanks for your reply, I will try that.

But I’d prefer to set the thread not to “solved” yet as this approach
a) is not sure if it fits my needs (also from a mechanical/roughness point of view) and
b) has the disadvantage of not providing any sort of identification

I would like to see if other users would come up with an alternative I did not think of?

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What’s kind of controller? I assume it’s not a colleague in Accounting or electrical component like Programmable Logic or Micro. And holster?

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Hi @brow its a prototype for an entertainment “gun” (therefore holster where to put it) that is later used in a darkride. There are several guns, each one has a holster in the chariot and each one needs to be calibrated once a ride is finished. For this calibration its easier if I would have a way to identify which gun is put into which holster

So my idea/first approach is to use RFID to check if the gun is in the holster and in which one.

Unfortunately, the RFID reader has a firmware bug I describe here and while @paulvha has found the reason for it, it is not yet clear if there is a way to fix the firmware (or is fixed by Sparkfun @TS-Russell ?)

So I am looking into reliable alternatives at least for detection if the gun is present in the holster or not. If photo interruptor is the way to go, I do that and find another way for identification gun/holster.

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I don’t know what a darkride or chariot holster is but are they optical video game guns? Dual wield Duck Hunt?

I mean, there’s so many ways to do a contact-identify and you’ve given so few details, it’s hard to know where to start.
You could make a little drill & finger pattern; this is done with ink and label cartridges.
You could make a little barcode; this is done with retail UPCs & library books.
You could make a little RF keyless entry; this is done with hotel and commercial doors.
You could have each of the guns flash unique pulses, IR or visible; this is done with household AV remote controls & some traffic control (see Opticon).
You could make a little magnetic stripe reader; this is done with credit cards or public parking entry/exit barricades.
You could pulse the gun’s force feedback system and read it by holster-local seismometers.
You could heat the guns to different temperatures and put thermometers in the holsters. Or put a unique odorant agent and air sniffer. Rad source and Geiger counter… admittedly, not all of these ideas are equally suitable.

Don’t the guns have cameras? A little symbol in the bottom of the holster?
What happens if the gun is detected in the wrong holster?
How many guns are there to realistically distinguish?

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UPDATE

Since the RFID reader can only tell if a device got close, but does not tell if the device was removed, I changed my setup and use the Hall Effect sensor now, which gives both “in range” and “out of range” readings: SparkFun Mini Linear 3D Hall-Effect Sensor - TMAG5273 (Qwiic)

ORIGINAL

For everyone else coming here, with help from forum people we have managed to fix the RFID reader, and I built the solution based around it.

More to the RFID reader: Qwiic RFID wrong readings after 20 reads - #50 by michaelheiml82