TIDA-00721: Passive NFC Temperature Patch

TIDA-00721 is a complete reference design for accurate temperature measurements using a passive NFC tag in a flexible patch form factor. The system offers temperature readings from tag to a NFC receiver such as a NFC enabled smartphone. The high accuracy temperature sensor (LMT70) is interfaced with an ADC (ADS1113) and the temperature data is sent to the reader with the NFC transponder (RF430CL330H).

Temperature is measured with the LMT70 high accuracy analog temperature sensor that interfaces with the 16-bit ADS1113 analog-to-digital converter (ADC). After the temperature data is digitized, the data is sent to the MSP430G2403 microcontroller which stores the data and then sends it to the RF430CL330H NFC transponder. The RF430CL330H bundles the data into the NFC protocol and sends it to a NFC reader.

The Passive NFC Temperature Patch Reference Design is a passive NFC tag that is powered by harvesting the NFC RF field. The NFC Temperature Patch is only functional within the RF field of the NFC reader.

Features:

• Human skin temperature sensing patch design

• Temperature data transfer with NFC interface

• Integrated PCB antenna

• Probe contacts for programming or troubleshooting