I was thinking of doing something like this and found this thread.
For anyone interested I will post my notes.
If you create your own circuit you can shrink the project down.
The bare bones circuit could be made by a nimble monkey, I've attached a photo of a working test.
As you can see its poorly put together and only uses a LED and magnet wire, but it works.
The antenna is a 8mm spiral.
I used a 805 LED (2mm x 1.25mm x 0.9mm) because that was what I had in my desk. 805's are good for quick mockups but you should use smaller 603's for size (1.6mm x 0.8mm x 0.8mm).
When put over a NFC reader the LED will pulse 3 times quickly followed by a pause and repeated.
Although this works its important to know that the antenna is not properly tuned to 13.56 mhz. I really dislike equations and don't own a oscilloscope so at the moment I can't build better.
If you have a oscilloscope tuning the antenna is just a matter of putting a capacitor before the LED to modify the frequency.
If you have math skills you can find formulas on the net to calculate 'perfect' antennas.
The power provided by NFC doesn't really require the LED to have a resistor. However I wouldn't risk implanting without one.
Hopefully this small amount of information can help more people start playing with the NFC LED idea without limitations of a premade FPC.
Comments
Echoing Erischilde, I know this is an old thread but I'm still very interested in this.
Has anyone contacted Steve Haworth about possibly working on something like this? I know he's an expert in silicone implants.
I was thinking of doing something like this and found this thread.
For anyone interested I will post my notes.
If you create your own circuit you can shrink the project down.
The bare bones circuit could be made by a nimble monkey, I've attached a photo of a working test.
As you can see its poorly put together and only uses a LED and magnet wire, but it works.
The antenna is a 8mm spiral.
I used a 805 LED (2mm x 1.25mm x 0.9mm) because that was what I had in my desk. 805's are good for quick mockups but you should use smaller 603's for size (1.6mm x 0.8mm x 0.8mm).
When put over a NFC reader the LED will pulse 3 times quickly followed by a pause and repeated.
Although this works its important to know that the antenna is not properly tuned to 13.56 mhz. I really dislike equations and don't own a oscilloscope so at the moment I can't build better.
If you have a oscilloscope tuning the antenna is just a matter of putting a capacitor before the LED to modify the frequency.
If you have math skills you can find formulas on the net to calculate 'perfect' antennas.
The power provided by NFC doesn't really require the LED to have a resistor. However I wouldn't risk implanting without one.
Hopefully this small amount of information can help more people start playing with the NFC LED idea without limitations of a premade FPC.