topic Re: Power-harvesting using NFC to power up a light sensor and LED in NFC

Power-harvesting using NFC to power up a light sensor and LED

samiha1234 — Sun, 24 Nov 2024 22:47:53 GMT

I want to design a circuit that can read data from a sensor (this is a color sensor ,AS7341) and it will be connected to a LED. I want to determine the light intensity of the LED using AS7341 (which requires 1.8V for operation, max 300µA consumption) and I'll use an led (HSMW-C230) which has a forward current of 5 mA with a typical forward voltage of 2.85 V.

I want the circuit to be lightweight and don't want to use a battery. I want to wirelessly get the sensor reading from the device to the smartphone, it will just be a one time reading with NFC. I was wondering if this feasible with an NFC power harvesting IC like the NTAG I²C Plus by NXP? Will it be enough to power up the led and the color sensor? Is the NTAG I²C Plus able to transfer the intensity data from AS7341 to smartphone via I2C or do I need a separate microcontroller for that task?

So as a summary:

When I bring my smartphone closer to my device, the led should light up and the AS7341 should get a light intensity reading from the LED. Then it should transfer this intensity data over to the smartphone. Is this something feasible? What are my options?

Thank you!

Re: Power-harvesting using NFC to power up a light sensor and LED

Tomas_Parizek — Mon, 02 Dec 2024 10:49:54 GMT

Hello samiha1234,

Please look at this product -> https://www.nxp.com/products/rfid-nfc/nfc-hf/connected-nfc-tags/ntag-5-link-nfc-forum-compliant-ic-bridge-for-iot-on-demand:NTAG5-LINK

Tomas

Re: Power-harvesting using NFC to power up a light sensor and LED

samiha1234 — Tue, 03 Dec 2024 20:24:01 GMT

Hi, thank you for sharing the link to the product. I checked it and it seems that the NTAG5 link can control I2C devices. So it must be programmable. I was wondering if you have example codes that I can refer to?

Thank you!

Re: Power-harvesting using NFC to power up a light sensor and LED

samiha1234 — Tue, 03 Dec 2024 21:15:53 GMT

I also found two development boards OM2NTP5332 board for the NTAG 5 link/switch, and the OM2NTA5332 board for the NTAG 5 boost. The one for the boost has a 10 by 10 mm antenna but the one for LINK has a larger antenna. I was wondering if the 10 by 10 mm antenna would work with the NTAG 5 LINK. I have little idea about antenna design so I am hoping to copy the design in the development board.

Re: Power-harvesting using NFC to power up a light sensor and LED

Tomas_Parizek — Fri, 06 Dec 2024 14:25:15 GMT

Hello samiha1234

For this product, we offer an evaluation board:

https://www.nxp.com/products/rfid-nfc/nfc-hf/connected-nfc-tags/ntag-5-development-kits:OM2NTX5332

+ some FW examples

Please look at them

Tomas