The NTAG I2C Test Card is a break-out board for the NTAG I2C chip with NFC antenna and power indicator LED built in. This card is great for people who want to experiment with the NTAG I2C chip and all its capabilities, including NFC field energy harvesting and I2C bus communication over NFC!
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are you shitting me…
We posted at the exact same time
get out of my head Amal… how did you kn…ohhhh the implants
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Guess that Titan backer coupon will get used a lot sooner than I was expecting.
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I’ve got some of these. They’re very cool.
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Was just as bright when powered by my phone, I just couldn’t take the picture then. It turns out this chip is an excellent LED driver because it’s self current-limiting at about 15mA. That means if you put more than 3 of the same LED in parallel you don’t really need resistors and you can’t overdrive/overheat them because they all self distribute the current among themselves. It doesn’t matter that the VOUT voltage (3.1V) exceeds the forward voltage of the LEDs (2V) because of the current ceiling. More than this many LEDs and it starts to noticeably dim.
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In a recent thread, I suggested that somebody get themselves an I2C Test card to test access on a door, to see if it is compatiable with an xSIID.
That, is one use for this card
BUT
I don’t currently have one, however, I am thinking of getting one.
Has anybody made “A THING” with one?
Practical or Not…But maybe just a little more practical than lighting up some LEDs
Here’s a good example
Also a couple of padlocks I reviewed used the I2C power harvesting to unlock ( Quite clever yet basic really )
Data sheet For reference if someone stumbles on this thread and wants some more info
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In case anybody is going to try something with the NTAG I2C Plus chip, since I designed the card I’ve had occasion to do further testing to compare the VOUT value at different current draws. Here’s a chart from the datasheet itself.
And here’s the data from my testing with various resistors on the NTI2C+ test card powered from an ACR-122U. As you can see the voltage droops considerably even at low current draw.
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