Quote from Pietro on July 6, 2020, 7:16 pm

Hi Chris

Good day, what you see can happen in case you use heavily weighted pieces.

The frequency we use is very low frequency and it's quite tolerant to metal magnetic field etc. but till some point. We saw this behaviour in few cases very heavily weighted pieces size 4,5"  set or above or even full metal. In this case the metal can be very big and disturb enough the tag which is not able to drag enough energy to supply itslelf and return the reading to the board. To go round this you need to lift a bit the big chunk of metal from the tag as you already experienced making some distance between the base and tag, since the disturbance is reduced with power factor 2 of distance even small distance (anyhow some mm still) will work. Our standard tags are 20mm diameter and this is quite ok basically in most of condition and sets but anyhow  to get round this in this special case like yours we did have made in the past different custom chips with bigger diameter 25 and 30mm where some friends wanted to embedd those very close in the weight of bigger pieces or make custom sets for big board. Bigger chips has bigger antenna and are work more efficiently in this case like yours.

Normally for such very heavy chess set you can use 25mm on pawns and 30mm on other pieces or probably 30mm on all pieces if the base of  pawn is big enough.

We did not make very many of those sets because as said they were particular cases, but i reckon this will fix the issue in your case too.

We do not have in stock those right now but PM me in case we have some sets  coming in August if you need with this bigger chips.

All the best

Pietro

Quote from julkal on July 9, 2020, 3:59 pm

I also have problems with weighted pieces and spend some time to explore this.
I wanted the chips being integrated in the pieces but unfortunately this was not possible.
What I found out is a little bit different from what Pietro says.
In my chess set:
https://royalchessmall.com/product/3-9-craftsman-knight-staunton-chess-pieces-only-set-triple-weighted-rose-wood/
there are two different types of metal. The king for instance has no problem if the metal has direct contact to the chip, but many of the much lighter weighted pawns have problems.
To test this, I put a heavy steal screw directly onto the chip and the chip works without any problems.
So it´s not how much weight is used in the piece, but what kind of metal is used.

To Pietro:
If you have the larger chips in stock, please send me a mail as I still would prefer to integrate the chips in the pieces.
Julian

Quote from Chris Theaker on July 18, 2020, 3:23 pm

Hi guys

Apologies for the lateness in my response back - I've been working on a few things in regard to this issue.

Firstly, I think it important to confirm that this is not an issue with the Certabo board - more about my own set up in general

I have found that heavily weighted pieces appear to effect the RFID recognition of the pieces as per my initial post however after a bit of experimentation have concluded this isn't helped with the usb power out from the PI (with a 3.5 inch attached) - I noticed connecting to my laptop the problem wasn't really there.

I tried a usb Y splinter with the PI (an extra pull on the power side) but this didn't resolve the issue -  adding a powered usb hub meant that 95% of the pieces were recognized via the PI - a few pieces still fail unless I 'double felt' them to move the chip slightly further from the base (without the hub the some pieces need almost triple felting).

I'm going to guess with the slightly larger RFID chip that Pietro mentioned will solve the issue completely.

If I was going to do this again, I think I would have purchased the pieces directly from Certabo but a little late for that.

@Pietro can you pop me on the list for the slightly larger RFID chips?

Again, at no stage is this a failing of the board but my suggestion is to bear this in mind if you are going for heavily weight pieces an use a Pi.

I hope the above helps

Kind regards

Chris

 

Quote from Pietro on July 21, 2020, 7:11 pm

Hello Chris Julian

Thank you for sharing your experience and for sure helps in improving the experience.

@Chris  its bit strange as the usb should be rated the same way on PC and Pi we will investigate a bit on that.

@ Julian We did some trials before closing about weight and different type of metal even magnets and do not thing it's type of metal, we suspect more it's related on some shapes coupling i mean that irrespective to the metal weight it maybe possible that the particular shape of the metal in thight contact with chips can result in some resonance effect which can more effectively affect the transmission. This we reckon is funny coincidence but it may be possible as the EM propagation can be affected by particular shapes or maybe ratio diameter thickness. Anyhow in both cases i think the 30mm will solve the problem as the antenna is different in size too.

Chris will send some 25 and 30mm chips as soon as we get in August (we will have those to sizes in addition to 20mm) so you can try  which work the best we also forwarded some to Julian before closing for summer so he may share eventually his experience with those sample we sent.

All the best

Pietro