Project ProposalProject 7: Drifters Lance Ellerbe - BS EE Jamal Maduro - BS CpE Peter Rivera - BS ME Anthony Sabido - BS ME
Project Overview • Develop a self-contained network of tracked surface drifters for near coastal application. • Housing • Electronics • Power System • GPS receiver • Radio transceiver • Microcontroller • Any of these drifters within range of the base station will then be able to send all the information from all other drifters, thus providing a self-contained drifter network. • Many such drifters are deployed globally by the National Oceanic and Atmospheric Administration (NOAA) as part of the world climate observation program.
Electrical Components • Microcontroller: • TI (Texas Instruments) MSP430G2553 microcontroller • Radio Transceiver • XBee-Pro XSC RF module’s • GPS module: • Maestro A2100 • Battery • Lithium ion • Temperature Sensor • Maxim DS18B20
Microcontroller ,Radio Transceiver, and GPS Engineer: Jamal Maduro
Radio Transceiver • Output power(Pt) = 30dbm (1W) • Transmitting Gain(Gt) = 16 dBi • Receiving Gain (Gr)= 16 dBi • Frequency Band = 902 – 928MHz ISM Band • Distance (d)= 15 miles (24.14016 kilometers) • = -57.348dBm
Temperature Sensor and Power Systems Engineer: Lance Ellerbe
Temperature Sensor Overview • Compared to the thermistor, the DS18B20 has memory and thus the temperature can be held until a more convenient time when the data can be logged. • 1 temperature reading per GPS fix
Temperature Sensor Maxim DS18B20 • Power Supply Range is 3.0V to 5.5V • Can read temperatures from -55°C to +125°C (-67°F to +257°F) with an accuracy of ±0.5°C from -10°C to +85°C • Converts Temperature to 12-Bit Digital Word in 750ms (Max)
Temperature Sensor Interfacing Maxim DS18B20 • Digital temperature sensor that uses serial communication through the DQ pin. • The DQ pin operates in half duplex and therefore cannot receive and send data at the same time.
Temperature Sensor Interfacing Maxim DS18B20
Power Systems Overview • Low Power Consumption • Each must be able to operate on 3.3V maximum. • The drifter network will be designed to use the least amount of power when transmitting data. • The power supply will be selected in order to supply the adequate amount of amp-hours in order to provide enough current for each electrical component to be operational throughout its 15 day deployment.
Power Systems Current Component Selection PROGRESS: • Xbee • Operation Voltage: 3.0 -3.6VDC • Current Draw: • Transmitting current: 256mA • Receiving Current: 50 mA • Maestro A2100-A/B • Operation Voltage: 3.0V - 3.3VDC • Current Draw: • Peak Acquisition Current 45mA • Microcontroller • Operation Voltage: 1.8V - 3.6V • Active mode: 230uA • Standby Mode: 0.5uA
Power Systems Ideal Battery Configuration Parallel configuration would be ideal to increase the amount of Amp-Hours to supply the adequate amount of current to Microcontroller, GPS module, Radio Transceiver and Temperature Sensor for a 15 day period. EXAMPLE
Power Systems Voltage regulation If battery chosen has a nominal voltage of more than 3.3 V, a voltage regulator will need to be implemented to maximize battery life and supply the correct operating voltage to the components.
Power Systems Voltage Regulator MAX882/MAX883/MAX884 line regulator • The regulator input supply voltage can range from 2.7V to 11.5V • Low Dropout Voltage: 220mV • Fixed Output voltages: 3.3V and 5V
Power Systems PCB protection • Lithium Ion batteries must connect to a protection circuit module to protect Li-Ion Battery from overcharge, over discharge and to prevent accidental battery explosion due to its extra high energy density. Battery
Power Systems Testing/ Verification • The testing of this task will include a number of power consumption tests. First, each electrical component will be attached separately to a multimeter or oscilloscope to validate that the component is operating within its electrical specifications. • Second, based on the results in the previous step the results can be then used to tweak network parameters such as transmission time or microprocessor algorithms in an attempt to lower power consumption and increase theoretical operation time.
Power Systems • Risk: • Temperature affecting battery characteristics
Power Systems Once all component selection has been finalized, the battery will be chosen based the voltage needed and the highest mAh that can be found.
Hull Design Engineers: Anthony Sabido and Peter Rivera
Concept Designs Block Design Cylindrical Design Spherical Design Semi-Spherical Design
Deciding Factors • Cost • The most critical factor. We can change the amount of material used and needed, but we can’t change the amount of money allotted. • Stability • Each design has it’s strengths and weaknesses. • Ex: Cylinders bob or tilt back and forth, blocks can snag, and spheres will roll/pitch.
Deciding Factors (cont.) • Ease of Fabrication • There is a risk of losing these at sea or a need for more. The Marine Lab should be able to reproduce them if necessary. • Impact Resistance and Weight • Each are there own category but carry the same weight in regards to decision making. Increasing impact resistance typically increases weight. However, these are weighted less than the other factors due to their effects on performance and project completion.