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

Block Diagram

Microcontroller

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.

Direction ControllersQuad Servo Directional Control

Melaxis Thermopile based Tilt Sensors

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.

Circuitry consists of a set of two thermo radiation sensors connected to adifferential amplifier. Two sets are used for X and Y axis.

Voltage is re-biased using an LM741 to suitable levels for MCU.

Imaging Interfaces

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.

HP Photosmart R707 Digital Camera

Etek EB-85A GPS Receiver

Connects to the MCU via SCI interface. Uses 2 SCI enabled Pins.

Provides GPS Location, Altitude, Velocity and Bearing.

External InterfacemicroSD 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.

Power Supply and ESCLM 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.

The End