A Mobile Sensor Platform for Indoor Location-Aware Navigation By Ryan Patterson, L3D URA

Existing Technology Bluesoft, Inc. Wi-Fi Tags Mobile Phone Triangulation GPS (Global Positioning Satellites)

Method of Operation Propagation Speed of Sound: m/s  320 m/s  feet/sec Propagation Speed of RF: c  m/s  983,571,058 feet/sec

Transmitter Development 3V Power Supply (‘AA’ Batteries) Ultrasound Transducers (Transmitters) Power Controller 40 KHz High Precision Oscillator 12V, High Power Charge Pump for Transmission Transmission Control

Transmitter Development Orange Trace shows Output to Transducers Blue Trace shows Oscillator Digital Output

Receiver Development 3V Power Supply (‘AA’ Batteries) Third & Fourth Stage Amplification (Variable Gain, up to 50) 5V Charge Pump for Power Supply Analog DC Voltage Converter Low-Pass Filter (Gain 2), After Second Stage Signal Threshold Detection First & Second Stage Amplification (Gain 25) Ultrasound Transducer (Receiver)

Receiver Development Transducer Input 1 st & 2 nd Stage Amp (x25) Low-Pass Filter (x2) 3 rd & 4 th Stage Amp ( x  50 ) Threshold Detector/Trigger Amplitude Detection Transducer Input (~3mV p-p); Transmitter within 5 feet Attempt of High-Pass Filter Orange is input; Blue is output

Receiver Development Transducer Input 1 st & 2 nd Stage Amp (x25) Low-Pass Filter (x2) 3 rd & 4 th Stage Amp ( x  50 ) Threshold Detector/Trigger Amplitude Detection Low-Pass Filter, no signal present (only noise); Orange is input, Blue is output Low-Pass Filter, weak signal present; Orange is input, Blue is output

Receiver Development Transducer Input 1 st & 2 nd Stage Amp (x25) Low-Pass Filter (x2) 3 rd & 4 th Stage Amp ( x  50 ) Threshold Detector/Trigger Amplitude Detection Low-Pass Filter, weak signal present; Orange is input, Blue is output Output to microcontroller upon detection of signal

Receiver Development Transducer Input 1 st & 2 nd Stage Amp (x25) Low-Pass Filter (x2) 3 rd & 4 th Stage Amp (x  50) Threshold Detector/Trigger Amplitude Detection 4 th Stage output; No signal (only noise); Full gain (x1250), Magenta is output, Green is trigger Threshold 4 th Stage output; No signal (only noise); Attenuated gain (x800), Magenta is output, Green is trigger Threshold

Range Testing Distance (Feet)Receiver Signal Amplitude (V) (Saturated) (Saturated) Transmitter in windowsill

Power Consumption Transmitter Power Consumption:  In Low Power Mode: 0 mA  In Standby Mode:15 mA  While Transmitting:104 mA Receiver Power Consumption:  In Low Power Mode: ~0.001 mA  In Standby Mode:37 mA  During Incoming Signal: 47 mA Power of Typical ‘AA’ Battery:  1850 mAH