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Would someone be interested to create Ben Bulsink's NFC Game Board?

Luka851

Hello everyone, 

I wanted to make a custom smart chess board and I came across to Ben Bulsink's open source technology on nfcgameboard.com. Following is a demo video of his creation: https://www.youtube.com/watch?v=4qKndjF60Js&t=12s. 

I wrote to him, and together we decided to upgrade the device and use the newer PN5180 IC instead of the CLRC632 IC that he used in the prototype. We used Playfultechnology library for PN5180 and encountered issues, such as the library wasn't detecting multiple tags. We have solved and improved that library, and that challenge now is solved, however we now encountered next issue which is connecting the IC to the external antenna. When we cut the PCB antenna traces on the module the IC stops to respond correctly, such as returning EEPROM and seems to get stuck in the loop even before it reaches communicating with the antenna. We don't know what may be causing this. Does anyone has any idea on it and how to fix this?

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My next question is will there be anyone who would be curious enough to also try to recreate the improved board? We want to create an open source technology - hardware as a sandbox, so anyone can make the board, and then write their own code to create any kind of the game on top on it, whatever they want, perhaps share their game on the common platform with other players to download and play their games. We are communicating through email and having more brains working on it will make things easier, faster, and thought maybe ask if anyone was interested to join, will be here to help and explain, what I know.

https://nfcgameboard.com/schematics/ - gives the idea, schematics, pcb, and similar, but for CLRC632. in short, we will make 15x15 grid board, using multiplex antennas - each antenna being 15x30mm, we will have then 30 antennas (15 rows, and 15 columns), instead of 225 small antennas, a matching circuit and one PN5180 IC. 

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  • 0

    "Does anyone has any idea on it and how to fix this?"

    Maybe it's trying to protect itself from your coil. I've never worked with NFC, but it seems obvious that there would need to be a way for the chip to protect itself from any items placed into the volume of the operating magnetic field that would, in effect, 'short' the field. A technology used extensively, like this is, needs to be pretty robust and difficult to kill. Imagine the economic mayhem if you could put a card reader out of action with a simple shorted turn. With a low frequency transformer, you'd rely on a fuse to get you out of trouble with a shorted secondary, but here it would either be indirect with a temperature monitor or directly by looking at the current supplied to the TX drive. It's possibly a bit complicated because of the need to power 16 tags simultaneously over a short period with the ISO scheme to enumerate them, so maybe it can't simply be a sensible limit easily within the dissipation limit of the chip - there possibly needs to be a time element to it as well.

    If the resonance of your makeshift coil with the parallel capacitance on the board is a long way from the operating frequency, it will look like a heavy load to the chip.

    Just a theory.

    If you know the parallel capacitance on the board, perhaps you could try the same capacitance alone with the coil, find the resonance, and then adjust the coil so the resonance moves back to 13.56MHz. Then your coil's inductance will match that of the one on the board. Use a good quality SMD cap, similar to the ones on the board (if you use an old leaded part, you'd just be measuring the self resonance of the cap). You could probably get it close enough to function, even if it's not spot on. After all, it can't be too hard a resonance because the signalling sidebands are so far away from the centre (800kHz is it?) and they'll want a reasonable signal level for the RX detection.

    The grid of coils is an interesting idea, but what would you use to do the multiplexing? Lots of RF relays?

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  • 0

    "Does anyone has any idea on it and how to fix this?"

    Maybe it's trying to protect itself from your coil. I've never worked with NFC, but it seems obvious that there would need to be a way for the chip to protect itself from any items placed into the volume of the operating magnetic field that would, in effect, 'short' the field. A technology used extensively, like this is, needs to be pretty robust and difficult to kill. Imagine the economic mayhem if you could put a card reader out of action with a simple shorted turn. With a low frequency transformer, you'd rely on a fuse to get you out of trouble with a shorted secondary, but here it would either be indirect with a temperature monitor or directly by looking at the current supplied to the TX drive. It's possibly a bit complicated because of the need to power 16 tags simultaneously over a short period with the ISO scheme to enumerate them, so maybe it can't simply be a sensible limit easily within the dissipation limit of the chip - there possibly needs to be a time element to it as well.

    If the resonance of your makeshift coil with the parallel capacitance on the board is a long way from the operating frequency, it will look like a heavy load to the chip.

    Just a theory.

    If you know the parallel capacitance on the board, perhaps you could try the same capacitance alone with the coil, find the resonance, and then adjust the coil so the resonance moves back to 13.56MHz. Then your coil's inductance will match that of the one on the board. Use a good quality SMD cap, similar to the ones on the board (if you use an old leaded part, you'd just be measuring the self resonance of the cap). You could probably get it close enough to function, even if it's not spot on. After all, it can't be too hard a resonance because the signalling sidebands are so far away from the centre (800kHz is it?) and they'll want a reasonable signal level for the RX detection.

    The grid of coils is an interesting idea, but what would you use to do the multiplexing? Lots of RF relays?

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