Inter-IC for Wearables (I2We): Power and Data Transfer over Double-sided Conductive Textile

We propose a power and data transfer network on a conductive fabric material based on an existing serial communication protocol, Inter-Integrated Circuit (I2C). We call the proposed network Inter-IC for Wearables (I2We). Continuous dc power and I2C-formatted data are simultaneously transferred to tiny sensor nodes distributed on a double-sided conductive textile. The textile has two conductive sides isolated from each other and is used as a single planar transmission line. I2C data are transferred along with dc power supply based on frequency division multiplexing (FDM). Two carriers are modulated with the clock (SCL) and the data (SDA) signals of I2C. A modulation and demodulation circuit is designed to enable using off-the-shelf I2C-interfaced sensor ICs. One significant originality of this work is that a special filter to enable passive modulation is designed by locating its impedance poles and zeros at appropriate frequencies. The proposed scheme enables flexible implementation of wearable sensor systems in which multiple off-the-shelf tiny sensors are distributed all over a wear.