TCSP – Schematics Design. Major Components. Freescale 9S12A64FCUE Microcontroller Etek EB-85A GPS Receiver Electronic Speed Controller HP Photosmart R707 Digital Camera microSD Card Reader External LCD Interface Melaxis Thermopile based Tilt Sensor LM2679 based Power Supply.
Decided on using a Pierce configuration for oscillator circuitry due to better performance and less circuitry as compared to Colpitts configuration.
Design was taken directly from manufacturer’s recommended layout.
Operating frequency will be set at 8 MHz via crystal oscillator.
Quad Servo Directional Control
Four servos Controlled via PWM through MCU during automated flight.
System Consists of four servos to control Rudder, Elevator and Ailerons.
Connects to MCU over a level translator to acquire a suitable voltage.
Melaxis Thermopile based Tilt Sensors
Circuitry consists of a set of two thermo radiation sensors connected to a
differential amplifier. Two sets are used for X and Y axis.
Voltage is re-biased using an LM741 to suitable levels for MCU.
Etek EB-85A GPS Receiver
Connects to the MCU via SCI interface. Uses 2 SCI enabled Pins.
Provides GPS Location, Altitude, Velocity and Bearing.
HP Photosmart R707 Digital Camera
Triggered via the MCU when target GPS Coordinates are reached. Uses 5 General IO Pins.
Uses a ULN2003A Darlington Transistor array to trigger voltage low.
microSD Card Interface
Used to store GPS coordinates.
Interacts using SPI connection on MCU via 5V to 3.3V level translators.
External LCD Interface
Used for diagnostic purposes, connects to the system via an SCI interface.
LM 2679 Power Supply
Uses LM2679SD-3.3 and LM2679SD-5.0 regulators.
Will converted 11.1V DC from 3 cell Li-Po batteries to a stable 3.3V and 5.0V at 92% Efficiency.
Electronic Speed Controller
Regulates the speed of the motor based on a PWM signal input into it.
Connected PWM pin on MCU during auto flight.