Swept-Frequency Tag Reader
Kai-yuh Hsiao (under Joe Paradiso)
Features
Uses dynamic imbalance of inductor bridge to detect response from resonant tags
Sweeps through 60kHz - 300kHz frequency band at 30 Hz
Detects all magnetic tags resonating within sweep frequencies with each sweep
Allows for real-time CHI interaction (faster than multi-chip RFID)
Inexpensive reader electronics and simple, easily-crafted tag structure permit quick adaptation to CHI, sensing projects
Musical
demo
written, harmonic and melodic changes reflect tag presence
Tag resonance frequency can be made to vary with physical parameters (e.g., force, position, etc.)
Voltage output reflects tag orientation and proximity to coil, enabling continuous response
Simplicity, safety, and tag structure very well suited to many applications,
including toys
updated 1998/10/4 by
khsiao@mit.edu