HE HUBBLE SPACE TELESCOPE Chapter XII The Hubble Space Telescope
Humble Hubble
description
Transcript of Humble Hubble
Humble HubbleTeam 18:
Evan Foote, Doug Wile,Tim Brown, Derek Pesyna
Background: http://apod.nasa.gov/apod/image/1302/ngc1763_lake_1600.jpg
Abstract
The proposed project is a self-aiming telescope. This telescope will obtain its global position and
the local time via GPS. It will then automatically orient itself to
point at a user selected target (star) using a variety of onboard
sensors.
Background: http://apod.nasa.gov/apod/image/1302/ngc1763_lake_1600.jpg
PSSCs• An ability to establish a coordinate system
based on the telescope's absolute global position via a GPS chipset, and relative orientation based on an accelerometer and electronic compass.
• An ability to compensate for combined variations in the Earth's gravitational and magnetic field, and variations in telescope geometry and mounting configurations via electronic user calibration.
Background: http://apod.nasa.gov/apod/image/1302/ngc1763_lake_1600.jpg
PSSCs• An ability to retrieve celestial coordinates and
targets via Bluetooth from an external host.• An ability to automatically move and point the
telescope at the designated target using feedback loops from integrated motor encoders.
• An ability to allow the user to manually override the telescope's target coordinate using an onboard electronic control interface, and to display information regarding headings on an onboard LCD.
Background: http://apod.nasa.gov/apod/image/1302/ngc1763_lake_1600.jpg
Block Diagram
Component Selection Rationale
• All on-board sensors are surface mount and 3-axis.• GPS switched to on-board antenna, but not
Bluetooth• CPU selection rationale:
Microprocessor PIC24FJ64GB106-I/PT - Microchip
S912XDG128F2MAL - Freescale
Program Memory (Flash) 64Kb 128KbI2C Bus 3 busses 1 busI/O Pins 52 pins 91 pinsPWM Channels 9 channels 8 channelsUART channel Yes YesOperating Voltage 2.0-3.6V 2.75-5.5VCost $6.26 $7.22
Packaging Design
Packaging Design
Schematic: Main Board
Schematic: Aux Board
Enable (High Z)
PWM Signal
Brake / Coast
Focus on Motor Control
ON / OFFinterrupt Hold Circuit on
DPDTLatching Switch
Focus on 3.3V regulator
Need to add headers
Schematic: Sensor Breakout Board
PCB LayoutMain Board
PIC micro
LCD header,shift register
RS232 line driver/receiver
Rotary encoders
Sensor boardheaders
Auxiliary boardheaders
VEX encoders
PCB LayoutAuxiliary Board
GPS receiver
H-bridges,associated logic
5V, 3.3V voltageconverters
5V, 3.3V, GND
Bluetooth module, 50 ohm antenna
Bluetooth + GPSheaders
H-bridge + power headers
PCB LayoutSensor Board
I2C + powerheaders
Accelerometer
Gyroscope
Compass
Errata
• VDD/VSS for I2C and VEX on main board• Replace temporary headers with real headers• Change 100uF capacitor from SMD to through-
hole on aux board• Unconnected pins on microcontroller, sensors• Make rotary encoder pads/hole larger
Software Design (Initialization)
StartInit.
Turn on GPS.
Get reading
Accel, compass reading
Move to level
position
Move to point North
Turn on Bluetooth,
Connect
Send GPS/time
data to Android
Android calcs
calibration targets
Select calb. target
Telescope points to
calb. target
User centers
telescope on target
Init.Done
Software Design (Main Loop)
StartMain
Get target from
Android
Move to target
Wait for new target
Project Completion Timeline
Week Starting on Evan Tim Doug Derek
2/25/2013Nothing Blink LED Aggregate Star data Simple GUI
3/4/2013PCB parts feedback I2C I2C Exams
3/11/2013Support Spring Break Spring Break Build Mount
3/18/201340% PCB Populated and testedTest software/ software design Support Fist
Bluetooth over android
3/25/2013PCB populated and testedTest software/ software design Support Fist
Android app done
4/1/2013PCB debuggedLow level development done
high level software development done
Android wiggle room
4/8/2013 WRAP UP ALL THE THINGS
4/15/2013 DEBUG ALL THE THINGS (and write the manual)
Questions?