Fabrication of a Wireless Sensor Network for Extreme Environments Faye Yuen EE 496/NASA Fellowship Design Review Presentation II Fall 2006

Project Overview Create a network of autonomous motes to collect data in extreme environments (i.e. the Arctic) that analog Mars. Meet NASA Goals and Objectives. Contribute to Dr. Chris McKay’s research.

Overall Block Diagram JN5121 Wireless Microcontroller External Power Supply (Solar) Water Sensor Computer

Water Sensor Why it was chosen How it works How it will be powered How it will be connected to the mote How data will be collected and sent Tests

Water Sensor: Why it was chosen Met needs – detects presence of water Understandable technology Compatible with motes Reasonably priced RoHS compliant

Water Sensor: How it Works No Water Water Internal reflection of LED light to photo-transistor

Water Sensor: Power Sensor requires +5 V to +12 (Note: the JN5121 microcontroller requires 2.2V to 3.6V)

Water Sensor: Connection to Mote Pin 34 (Analogue to Digital input) on the mote’s Expansion Connector Input Signal: ADC1 (connects to microcontroller)

Water Sensor: Data Collection FLASH memory holds the application program that the internal processor will run Memory can be programmed by writing code in Bash shell and using the JN5121 Flash Programmer Track Packets (data transmitted on positive or negative edge of clock) Programming Code…

Water Sensor: Programming Code PRIVATE void vAdcDataLogger(uint16 *pau16DataBuffer, uint32 u32Length) {int i; /* configure Analogue Peripheral timings, interrupt & ref voltage */ vAHI_ApConfigure(E_AHI_AP_REGULATOR_ENABLE, E_AHI_AP_INT_DISABLE, E_AHI_AP_SAMPLE_2, E_AHI_AP_CLOCKDIV_500KHZ, E_AHI_AP_INTREF); while(!bAHI_APRegulatorEnabled); /* configure and enable DAC */ vAHI_AdcEnable(E_AHI_ADC_CONVERT_ENABLE, E_AHI_AP_INPUT_RANGE_1, E_AHI_ADC_SRC_ADC_1); while(TRUE) {for(i=0;i<u32Length;i++) {vAHI_AdcStartSample(); /* start capture */ while(bAHI_AdcPoll()); /*busy wait until capture complete */ pau16DataBuffer[i]=u16AHI_AdcRead(); /* store in buffer */ }

Water Sensor: Tests Detects water? Accuracy? Reliability? Response to different water forms (ex. liquid, solid, gas)? How much of dome needs to be covered by water for it to indicate its presence?

Remaining Work Build (waiting for supplies) Test Casing Documentation… REVISE 496 REPORT!

Timeline for Completion Previous Gantt Chart (from Design Review I): Completed Today n/a Waiting for Supplies Revised Gantt Chart…

Gantt Chart

Thank You! Any Questions?