• Elliot Buller• Luke Ciavonne• Mehdi Mehrpartou

Advisor:

Dr. Steven Reising

• Passive microwave measurement device• Measures black body radiation• Tuned to resonant frequency of water vapor

(22.235 GHz)• Extremely sensitive to changes in water vapor• Can detect water vapor through cloud cover

• Forecasting weather•Measuring sea surface temperature•Cloud cover•Precipitation rate

• Predicting larger regional and global trends• Study of atmosphere and surfaces of planets

• Embedded Intel SBC running Windows 98• Off the shelf boards for data acquisition • Custom power conditioning circuit• Limitations

• Prone to failure• Power requirements• Heat produced

• Low power consumption (<3 Watts)• Small Size• Reliable• Low latency interrupt response• Sufficient I/O ports (3 Serial ports, 16 A/D channels)

• Two board solution:• Custom designed 4 layer PC104 daughter card designed by Pat Kusbel• ARM9 based commercial single board computer• Boards communicate over PC104 bus

Device Power (prev) Power (new)

Computing System 6.9 W 1.8 W

Analog Board 5.6 W 0.5 W

RF 2.5 W 2.5 W

Total 15 W 4.5 W

• 6 Switching Voltage Regulators• High Efficiency at High Currents ( > 90%)

• 7 Linear Voltage Regulators • Low Noise (typically 30 μVrms, 10 Hz to 100 kHz)• Low Quiescent Current (30 μA) • Low Output to Input Ratio for Higher Efficiency

• DC Voltage Levels• Output Voltage Ripple• Noise • Stability

• Transient Response• Electromagnetic Interference (EMI)

• Custom board digitizes 4 analog channels from Radiometer• ARM9 board initializes and controls custom board• Boards communicate with each other over PC104 bus

• Custom board includes FPGA running Microblaze processor• Processor tasks include:

•Periodically polling ADCs•Buffering samples on-board•Maintain local time-base•Control off-board power to radiometer

• Processor clock is faster than PC104 clock• Provide temporary storage of data• Send periodic interrupt request to trigger data dump to ARM9 board• Receive control parameters from ARM9 board

• Linux kernel module•Service Interrupts from FPGA

• SD Card storage daemon•Shuttles data from device driver to SD cards

• Temperature control software•Communicates with Peltier unit to control temp within 0.1˚C

• Time management•Communicates with GPS to store and synchronize time on both boards

• Hardware•Finish testing power supplies•Run transient analysis on DACs•Test all power supplies with dummy loads

• Software•Write time management software to synchronize with GPS•Write Microblaze mini-kernel to interface to ADCs•Write software to control positioning apparatus•Write user interface to configure device and dump data

• Flavio Iturbide-Sanchez• Olivera Notaros

Dr. Steven Reising

Pat Kusbel

Sharmila Padmanabhan