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!
are you shitting meā¦
We posted at the exact same time
get out of my head Amalā¦ how did you knā¦ohhhh the implants
Guess that Titan backer coupon will get used a lot sooner than I was expecting.
Iāve got some of these. Theyāre very cool.
Was just as bright when powered by my phone, I just couldnāt take the picture then. It turns out this chip is an excellent LED driver because itās self current-limiting at about 15mA. That means if you put more than 3 of the same LED in parallel you donāt really need resistors and you canāt overdrive/overheat them because they all self distribute the current among themselves. It doesnāt 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.
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
https://dangerousthings.com/product/nitc/
BUT
I donāt currently have one, however, I am thinking of getting one.
Has anybody made āA THINGā with one?
Practical or Notā¦But maybe just a little more practical than lighting up some LEDs
Hereās 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
In case anybody is going to try something with the NTAG I2C Plus chip, since I designed the card Iāve had occasion to do further testing to compare the VOUT value at different current draws. Hereās a chart from the datasheet itself.
And hereās 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.