Cellphones do not blink with an actual chip in the field it is just the xLEDs as the phone is looking for a tag, once a tag is detected like any of the NTAG chips it will go to full power and stay on. An example is the xSIID.
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My experience is the opposite with my Xsiid it will blink while searching, once it gets a good read it turns off
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What phone do you have? That is not standard behavior.
This is an example of standard behavior and works this way for all non iPhone devices I have tested with xSIID also
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iPhone xr
Yeah this is ‘KR1’ in the code, ‘KR2’ has the trailing LED. Look at videos of Kitt lol.
Yep that’s the one.
NTAG I2C and a microcontroller.
Frayed knot ;-)…I’ve used this device for a few years 
Messaged you.
Thank you
Works fine with a phone. Remember this still carries NFC functionality, so once the chip is detected the carrier is constant.
NTAG I2C, microcontroller, LEDs and a few passive components. The LEDs are 0402, all passives are 0201.
I can…but I ain’t selling anything lol.
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The PCB is 0.1mm polyimide in black with gold flash…very JPS. For my own use I’ve some 2.4mm O.D biocompatible acrylic tube and filler that I can hot air seal…after several emails the European Schott guy never answered my request for glass (and I wasn’t freeloading for samples)! The antenna (transformer secondary 
) is the usual ferrite loaded coil on the rear.
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My wants are strong with this one 
My need for a blinky is slowly growing bigger and bigger these days, so I’ll call dibs on one too if they reach implant 
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You lost me, I didn’t expect you to be selling these,
(Im banking on you and Amal working something out and seeing these as a new option)
I’m mostly curious what the leds look like with a lower and more intermittent nfc field
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I would be down for 2. Love the blinkies.
That’s awesome!
A few questions if you have the time to answer -
- what microcontroller are you using in conjunction with the NTAG chip / what package?
- where did you get that pcb made? I’m only really aware of OSHPark doing cheap, small quantity flex PCBs, but their recommended minimum width is 6.35mm not 2mm
- would you be willing to share sources / code at all (not expecting or even wanting support, but very intrigued)?
Check out PCBWay!
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I have, but unless I’m configuring it wrongly (quite possible since I don’t have test / proper gerbers) the setup costs are insane, making 300 quantity cost the same as 10!!
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Yeah, you’re gonna pay $120 no matter what, but you’ll get a few hundred boards. You’d pay ~$80 for a few hundred Fr-4 boards so it’s not a huge jump. The barrier to entry is just higher. The tolerances are like 8x more precise by default though so you can make smaller boards than you ever would be able to otherwise.
Ultimately I don’t think the cost is that bad. 10 years ago you’d have paid $500 for 100 flex PCBs, and that was in back then money.
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From PCBWay yes, but not from OSHPark if I understand their website correctly. Their price is $10 per spare inch for 3 copies… which means for a 6.35mm x 14mm flex pcb (their recommended minimum width is 6.35mm not 2mm) three copies should cost $1.30 (I only want it for myself, obviously amal might want the much larger quantity)
If you find out more about their MOQ let me know. OSHPark is great, but I was under the impression you would need to order more than 1 square inch of board space per customer.
There’s also the downside that you have to wait for them to fill up a panel before they’ll order, which for something less common like a small batch flex PCB could be a bit longer than you would like.
I work in synthetic biology designing and studying autoluminescent plants and animals. I came across an interesting article about wavelengths of light and how green is not an ideal florescent protein for animal tissues, as blue and green light is readily absorbed by human tissues “…signals from enzymes with spectral peaks in the blue/green wavelengths (∼475to515nm)(∼475to515nm) were strongly absorbed with a pattern suggestive of a significant influence of hemoglobin. Enzymes with spectral peaks in the orange/red wavelengths (∼590to650nm)(∼590to650nm) were less absorbed, with greater penetration through tissues”
https://www.spiedigitallibrary.org/journals/journal-of-biomedical-optics/volume-10/issue-04/041210/Emission-spectra-of-bioluminescent-reporters-and-interaction-with-mammalian-tissue/10.1117/1.2032388.full?SSO=1
So I’m definitely not saying it won’t work with green light but I hypothesize that the green light will appear much more dim beneath the skin if you ever plan to implant, and this is really cool I would just recommend red LED’s for maximum brightness and visibility once implanted 
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It seems like that article mainly focuses on light produced quite deep within the tissue (refers to centimeters of tissue), rather than just barely subdermally. For existing LED implants (including the xSIID), anecdotally it’s been found that green is actually the brightest, followed by blue, then red, and amber as the least bright. Amal mentions this in this forum post, and comparing my own blue implant to pictures of those with red implants, it seems to hold true.
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@darthdomo Well hey I’ve never heard that but it certainly makes sense! You’re definitely right this is talking about multi-layered tissues from deep to superficial and I was wondering that myself, as the article largely accredits this phenomenon to hemoglobin, which there’s very little hemoglobin in the fascia tissues. So I did wonder how this effect would pan out in the strictly superficial tissues with little tissue to disperse the light, but that’s very interesting I’d have to try this out perhaps and test it! If anyone gets this implanted by chance I’d love to see the results 
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You most certainly can’t do that from other people’s videos. You need to meet the other implantee in the flesh, put your hand in the same light and same position as theirs and then compare - and even that is subjective.
Ultimately, it’s just a matter of perception. Maybe this or that light is dimmer, but if the eye sees it better, then it looks brighter.
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