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EE 296 Icarus Project Group Members: JimyLeah Castro Jeremy Chan Eric Lee Sae Yoon. Project Overview. Use a Zilog Microcontroller to handle telemetry Multiplex several sensor readings via communications channel Transmit data wirelessly. Overview of Initial Engineering Objectives.
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EE 296 Icarus Project Group Members: JimyLeah Castro Jeremy Chan Eric Lee Sae Yoon
Project Overview • Use a Zilog Microcontroller to handle telemetry • Multiplex several sensor readings via communications channel • Transmit data wirelessly
Overview of Initial Engineering Objectives • Interface with sensors • Utilize a radio system • Design a portable device • Create a custom printed circuit board • Apply theoretical concepts
Design Structure – Circuit Schematic Battery Feedback Circuit Power Supply Circuit MAXStream9 RF Modem GPS Module Zilog Encore Microcontroller Crystal Oscillator Circuit Temperature Sensor Debug/Programming Port Motorola Pressure Sensor and Attenuator Circuit
Design StructureCircuit Modules • Power Supply (5V, 3.3V) • Zilog 40 Pin 64KB Flash Microcontroller • MAXStream9 RF Modems • Microchip TC1074A Temperature Sensor • Lassen IQ+ GPS • MPX4115A Motorola Pressure Sensor • LM324 Operational Amplifier • Ultra Low Power Attenuator Circuits
Design Features • Bidirectional Communication – full duplex command and telemetry via wireless • Power Trim Mode – hibernate the radio in order to cut power consumption by 33% • Low Battery Detection and Response – automatic power trimming, warnings • Attenuator Circuits – to scale voltages with high accuracy and low power consumption
Challenges Encountered • Programming Limitations • Proprietary Serial Protocol Implementation • High Power Consumption • Scheduling Conflicts • Vibrations Affect Pressure Readings
Message Formats • Sensor Data • $DAT:76.1,F,24.5,C,100.421,kPa,8.29,V* • GPS Data (NEMA 0183 Standard) • $GPGGA,034944.00,2116.3475,N,15748.0174,W,1,03,2.38,00089,M,004,M,,*73 • System Status Messages • $STAT_BATT,7.33,V,LOW-BATT-TRIM-MODE-ACTIVATED* • $STAT_BATT,7.38,V,LOW-BATT* • NEMA style messages allow for easy reading and data filtering
Outstanding Problems • SHT11 Scrapped • GPS: Unable to Acquire GPS Fix Reliably
Future Improvements • On-board Data Logging via Flash Device • Additional Sensors • Implement remote control devices • Higher Resolution ADC for Pressure • Space Reduction • Power Optimization • Data Checksum Implementation