Bluetooth Wireless
Telescope
Computer Interface
by
Monroe Pattillo
President, SFAAA
Bluetooth 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
Bluetooth Wireless Telescope Computer Interface 07.ppt 2 Created 20060814 MWP Updated 20061004 MWP
Bluetooth 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)
Bluetooth Wireless Telescope Computer Interface 07.ppt 3 Created 20060814 MWP Updated 20061004 MWP
Bluetooth Wireless Telescope Computer Interface
Standards Based Wireless Technology Choices
Bluetooth (chosen for this validation)
+ small, inexpensive, low power
- addressing, range, no Internet routing
Wi-Fi (for the next solution validation)
+ range, addressing, Internet routing
- larger, more expense, more power
Bluetooth Wireless Telescope Computer Interface 07.ppt 4 Created 20060814 MWP Updated 20061004 MWP
Bluetooth Wireless Telescope Computer Interface
Bluetooth Product Selection Criteria
Bluetooth version 1.1 (compatible w/2.0 EDR)
Class 1 (Classes 2 & 3 are shorter range)
Support Bluetooth Serial Port Profile (SPP)
Power - hardware interface vs external power
Adaptable to field power (12-18V DC)
Product open information and availability
Adaptable for telescope control
Bluetooth Wireless Telescope Computer Interface 07.ppt 5 Created 20060814 MWP Updated 20061004 MWP
Bluetooth Wireless Telescope Computer Interface
Bluetooth Application/Protocol Layers
Bluetooth
PC or PDA Serial Device Adapter
Bluetooth
Bluetooth Interface 2.4GHz Wireless Bluetooth Interface
Paired Device Paired Device Telescope
SPP Client SPP Server RS-232
Telescope RS-232 Serial
Application Port Interface
Virtual
COM
Port
Driver
Virtual Cable
Bluetooth Wireless Telescope Computer Interface 07.ppt 6 Created 20060814 MWP Updated 20061004 MWP
Bluetooth Wireless Telescope Computer Interface
BlueConsole BC-02
Bluetooth 1.1, class 1, SPP, multipoint w/3.7
Very small, low power (can run on 9-18V DC)
Adaptable to external power (9V battery)
Product adaptable to telescope control
Bluetooth Wireless Telescope Computer Interface 07.ppt 7 Created 20060814 MWP Updated 20061004 MWP
Bluetooth Wireless Telescope Computer Interface
Adapting the BC-02 for use with Meade 8” LX-200 Classic
Adapt BC-02’s RJ-45 to LX-200’s RJ-14
Need simple, easy to reproduce solution
Need to dress it neatly to the LX-200
Approach: RJ-11 to RJ-45 to BC-02
Modify 1 ft phone cord, add RJ-45 coupler
Velcro BC-02 to side of LX-200
Bluetooth Wireless Telescope Computer Interface 07.ppt 8 Created 20060814 MWP Updated 20061004 MWP
Bluetooth Wireless Telescope Computer Interface
Wiring for the modified telephone cord
Use a stranded wire modular cord, not silver satin (foil over plastic)
Unmodified End Modified End
Yellow, Green, Red, Black Yellow, Black, NC, Red
Y B N R
Y G R B C
Green not connected as that pin
is power output from the scope
Bluetooth Wireless Telescope Computer Interface 07.ppt 9 Created 20060814 MWP Updated 20061004 MWP
Bluetooth Wireless Telescope Computer Interface
Bluetooth on PC
You’ll need Bluetooth 1.1 or 2.0 on your PC
Class 1 is long range, 2 is shorter, 3 shortest
Can be built-in, USB, or PCMCIA/CardBus
Install Bluetooth software on PC
No Bluetooth servers needed at PC end
Discover the BlueConsole BC-02
Pair with it (1234 is default pairing key)
Connect to the SPP Server in the BC-02
Try to set PC virtual COM port to COM1..4
Some old telescope apps only see COM1..4
Bluetooth Wireless Telescope Computer Interface 07.ppt 10 Created 20060814 MWP Updated 20061004 MWP
Bluetooth Wireless Telescope Computer Interface
The Solution
Velcro mounted to side of Meade LX-200 Classic
(mounted and cable tied clear of fork arms movement)
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Bluetooth Wireless Telescope Computer Interface
Operation
Connect coupler and cable to BC-02
Connect BC-02 cable to telescope
Attach battery to BC-02
Mount BC-02, cable, and battery to scope
Establish Bluetooth between PC & BC-02
Launch telescope control application(s) on PC
Enable telescope interface to virtual COM port
Bluetooth Wireless Telescope Computer Interface 07.ppt 12 Created 20060814 MWP Updated 20061004 MWP
Bluetooth Wireless Telescope Computer Interface
Icing on the Cake
I own an H-P iPAQ 2215 Windows based PDA
It has built-in Bluetooth
I installed a copy of TheSky Pocket Edition
Enabled Bluetooth on PDA
Enabled scope interface to virtual COM port
!!! wireless scope paddle + planetarium !!!
(simultaneous PC & PDA scope control using BC-02 3.7 firmware)
Bluetooth Wireless Telescope Computer Interface 07.ppt 13 Created 20060814 MWP Updated 20061004 MWP
Bluetooth Wireless Telescope Computer Interface
Contact Information
BlueConsole – BC-02
www.blueconsole.com
TheSky Pocket Edition (only for Windows based PDAs)
www.bisque.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
Bluetooth Wireless Telescope Computer Interface 07.ppt 14 Created 20060814 MWP Updated 20061004 MWP
Bluetooth Wireless Telescope Computer Interface
Next Projects
Create a similar solution based upon Wi-Fi
Improved range and addressing
Possibility of Internet routing
Slightly higher cost and package size
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
Bluetooth Wireless Telescope Computer Interface 07.ppt 15 Created 20060814 MWP Updated 20061004 MWP