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Wi-Fi Wireless
Telescope
Computer Interface
by
Monroe Pattillo
President, SFAAA
Wi-Fi Wireless Telescope Computer Interface
Goals
Eliminate cable between computer and scope
Remove nighttime trip hazard of cable
Reduce scope setup/teardown times
Identify generic, standards based solution
Validate solution with existing equipment
Document and disseminate solution to others
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Created 20060816 MWP Modified 20061004 MWP
Wi-Fi Wireless Telescope Computer Interface
Telescope Computer Interface
Serial (not parallel)
Asynchronous (not char. or bit synchronous)
RS-232 (TIA/EIA-232E)
9600 bps, no parity, 1 stop bit
No handshake (not hardware, not software)
Classical three wire interface (TxD, RxD, Gnd)
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Created 20060816 MWP Modified 20061004 MWP
Wi-Fi Wireless Telescope Computer Interface
Standards Based Wireless Technology Choices
Wi-Fi (chosen for this validation)
+ flexible range, addressing, Internet routing
- larger, more expense, more power
Bluetooth (previous solution validation)
+ small, inexpensive, low power
- addessing, short range, no Internet routing
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Created 20060816 MWP Modified 20061004 MWP
Wi-Fi Wireless Telescope Computer Interface
Wi-Fi Product Selection Criteria
Wi-Fi IEEE 802.11b (compatible w/802.11g)
Supports TCP/IP tunneling and web server
External power (doesn’t use interface power)
Product open information and availability
Product adaptable to telescope control
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Created 20060816 MWP Modified 20061004 MWP
Wi-Fi Wireless Telescope Computer Interface
Wi-Fi Application/Protocol Layers
Wi-Fi 802.11b
Serial Device Adapter
PC or PDA
Wi-Fi 802.11b
Ethernet Interface 2.4GHz Wireless Ethernet Interface
Wired
IP Protocol
IP Protocol
Interface,
TCP
TCP
Wireless
Client
Server
Access
Telescope
RS-232
Point,
Application
Port
Wireless
Virtual
Router,
COM
or
Port
Internet
Driver
Telescope
RS-232
Serial
Interface
Virtual Cable
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Created 20060816 MWP Modified 20061004 MWP
Wi-Fi Wireless Telescope Computer Interface
Quatech ABSE-100D
IEEE 802.11b, TCP/IP tunnel, web server config
Removable ant, Indicators, Mounting sleeve
Captive serial cable, Includes AC-DC adapter
Product adaptable to telescope control
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Wi-Fi Wireless Telescope Computer Interface
Adapting the ABSE-100D to Meade 8” LX-200 Classic
Adapt ABSE-100D DB-9M to LX-200’s RJ-14
Need simple, easy to reproduce solution
Need to dress it neatly to the LX-200
Sol: RJ-11 to RJ-45 to DB-9 to ABSE-100D
1 ft telephone cord and RJ-45/DB-9 adapter
Velcro ABSE-100D to side of LX-200
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Created 20060816 MWP Modified 20061004 MWP
Wi-Fi Wireless Telescope Computer Interface
Wiring for the unmodified telephone crossover cord
Unmodified End
Unmodified End
Black, Red, Green, Yellow Yellow, Green, Red, Black
B R
Y G R B
G Y
Just an unmodified standard crossover phone cord
Use a stranded wire cord, not silver satin (foil over plastic)
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Created 20060816 MWP Modified 20061004 MWP
Wi-Fi Wireless Telescope Computer Interface
Wi-Fi on PC
You need Wi-Fi IEEE 802.11b (or g) on PC
Built-in, USB, or PCMCIA/CardBus
Discover ABSE-100D, configure via web
Set it to known IP address and port number
Install VCOM software (or its equivalent)
Establish virtual COM port (TCP port tunnel)
Try to set PC virtual COM port to COM1..4
DPAC VCOM vs Lantronix COM port redirector
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Created 20060816 MWP Modified 20061004 MWP
Wi-Fi Wireless Telescope Computer Interface
The Solution
ABSE-100D
Velcro mounted
and wire tied to
the side of Meade
LX-200 Classic
(clear of fork arm movement)
The Wi-Fi antenna can be
tilted outward and
rotated as needed or an
extension cable can be
used to relocate or to
upgrade the antenna
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Created 20060816 MWP Modified 20061004 MWP
Wi-Fi Wireless Telescope Computer Interface
Operation
Mount and connect solution to telescope
Connect power to ABSE-100D
Establish Wi-Fi network
Connect PC to IP network to Wi-Fi network
Connect PC virtual COM port to ABSE-100D
Launch telescope control application on PC
Enable telescope interface to virtual COM port
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Wi-Fi Wireless Telescope Computer Interface
Contact Information
Quatech ABSE-100D
www.quatech.com
Lantronix COM port redirector
www.lantronix.com
Monroe Pattillo
President
South Florida Amateur
Astronomers Association, Inc. (SFAAA)
www.sfaaa.com
Fox Observatory, inside Markham Park
Open to public Saturday evenings til midnight
NW corner of I-75-N/I-595 and FL-869/I-75-S
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Wi-Fi Wireless Telescope Computer Interface
Other Projects
Previous Project
Created wireless solution based upon Bluetooth
Slightly lower cost, smaller pkg size than Wi-Fi
Next Projects
Create a poor man’s StellarCam
Windows PC based application and server
Source agnostic (video, webcam, files)
Format agnostic (BMP, JPEG, TIFF)
Stack and adjust images as they arrive
Result image accessed via web browser
Create Wi-Fi based control and imaging solution
Wired Ethernet Servers - RS-232 & Video
Concentration - Wired Ethernet to Wi-Fi
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