RFID/NFC

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RFID/NFC
« on: 15 / April / 2014, 15:59:47 »
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I can produce an RFID and/or NFC reader to mount onboard a DSLR with a USB dongle to the camera. What I don't know how to do is to hack the firmware so that the read RFID data is dumped into the EXIF Comment field. I would love to collaborate with someone on this.

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Offline reyalp

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Re: RFID/NFC
« Reply #1 on: 15 / April / 2014, 16:45:41 »
I can produce an RFID and/or NFC reader to mount onboard a DSLR with a USB dongle to the camera.
Note that the camera is a USB device not a USB host, so if you wanted to do USB protocol communication, you would need a host separate from the camera. You would then need to do your communication with the PTP extension.

You could presumably hook your RFID reader up to a micro-controller and have it signal the camera with USB power like the USB remote.

Also note that CHDK does not run on any DSLR. Magic Lantern and some other hacks run on DSLRs.
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What I don't know how to do is to hack the firmware so that the read RFID data is dumped into the EXIF Comment field. I would love to collaborate with someone on this.
AFAIK we don't know how to modify this value before the camera writes the exif. It presumably could be modified later in using normal file IO, although you would need to parse enough of the exif to find it and possibly adjust some offsets.
A simpler solution would be to just log something to a file along with the image number and combine them later.
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