NFC Sensor System Mike Pappas Nigel Himmelreich Eric

NFC Sensor System Mike Pappas, Nigel Himmelreich, Eric Anderson

Overview 1. Sensor module o Sensors connected to a microcontroller and transmits data over NFC (Near Field Communication) 2. Reader module o Receives data over NFC, logs the data, and retransmits over Bluetooth 3. Smartphone o Receives values, stores the data, and displays graphically

Motivation ● Inspired by a “disposable smart bandage” concept ● Proof of concept that real-time sensor data can be transmitted over NFC ● Ultra-low power operation ● Reusable logging portion attaches overtop the sensors ● Inductively powered

Medical Relevance ● Device could monitor wound moisture/humidity, ammonia, oxygen and temperature levels ● Status of a wound without removing a dressing ● Improved costs ● Hospital bed ~$2500/day VS. ~$1000/day for home visit ● Keep patient out of hospital and improve care

The System

Sensor Module ● Texas Instruments RF 430 NFC Module ● Texas Instruments MSP 430 Microcontroller ● Analog temperature sensor accurate to ± 1℃ ● Photoresistor for measuring light intensity

Sensor Module ● Obtains analog sensor data, converts to digital, then transmits over NFC ● Uses between 5. 2 -6. 17 m. W of power ● Estimated 5 days battery life on a single watch battery (CR 2032) ● Induction power

Reader Module ● Altera DE 0 Nano FPGA o Running Micro. C/OS, it logs data and transfers values between NFC and Bluetooth ● Adafruit PN 532 NFC Shield o Connected with I 2 C, it triggers an interrupt in the DE 0 when an ISO 14443 B device is in range

Reader Module ● Olimex MOD-BT Bluetooth Module o Connected via a serial UART connection o Setup as a server, sending sensor values to any connected device ● The data from the NFC reader is sent over the Bluetooth connection

Reader Module ● Is powered by any 3. 3 V source ● Can be placed over a sensor for a long period of time to log data ● Provides the inductive power

Application ● Android Application ● Fetchs Data o NFC connection, by tapping phone on to NFC portion of sensor module o Bluetooth connection, waits for an incoming bluetooth string with data ● Data is parsed and displayed to user ● Data is saved on to memory to retain history

Application ● History view on application allows user to view past readings ● Graph view displays a graph of the data o Temperature reading and light reading are easily switched by pressing a button o Each graph can be divided by various amounts of days

Demo

Challenges ● New development board (MSP 430) ● Android development with NFC and Bluetooth connections ● Porting library for NFC reader and extend to read type B devices ● NFC hardware limitations

Results ● Successfully able to implement the MSP 430 architecture for NFC communications ● Able to obtain analog sensor data and transmit over an NDEF (NFC) message ● Successfully able to transmit NFC data to an Android device to store and display in an application

Results ● Able to send Bluetooth data and able to receive NFC information on the DE 0 ● Able to receive Bluetooth data on the Android smartphone ● Induction power to sensor module

Future Extensions ● Logging to a computer or a server for remote monitoring of data ● Attach a screen to the reader module for real time data without a smartphone ● Induction powered

Future Medical Extensions ● RFID Integrated Chip ● Low cost - dimes to pennies per chip ● Important sensors

Questions?