bluetooth wireless telescope computer interface

Bluetooth WirelessTelescope

Computer Interfaceby

Monroe PattilloPresident, SFAAA

Bluetooth Wireless Telescope Computer Interface

2Bluetooth Wireless Telescope Computer Interface 07.ppt Created 20060814 MWP Updated 20061004 MWP

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



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)



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 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 Application/Protocol Layers

PC or PDA

Bluetooth Interface

Telescope

RS-232SerialInterface

BluetoothSerial Device Adapter

Bluetooth2.4GHz Wireless

Paired Device

SPP Client

RS-232Port

VirtualCOMPort

Driver

Virtual Cable

TelescopeApplication

SPP Server

Paired Device

Bluetooth 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



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



Wiring for the modified telephone cord

Unmodified EndYellow, Green, Red, Black

Modified EndYellow, Black, NC, Red

YY GG RR BBYY BB NN

CCRR

Green not connected as that pin is power output from the scope

Use a stranded wire modular cord, not silver satin (foil over plastic)



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



The Solution

Velcro mounted to side of Meade LX-200 Classic(mounted and cable tied clear of fork arms movement)



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



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)



Contact Information

BlueConsole – BC-02www.blueconsole.com

TheSky Pocket Edition (only for Windows based PDAs)www.bisque.com

Monroe PattilloPresidentSouth Florida Amateur Astronomers Association, Inc. (SFAAA)www.sfaaa.comFox Observatory, inside Markham ParkOpen to public Saturday evenings til midnightNW corner of I-75-N/I-595 and FL-869/I-75-S



Next Projects

Create a similar solution based upon Wi-FiImproved range and addressingPossibility of Internet routingSlightly higher cost and package size

Create a poor man’s StellarCamWindows PC based application and serverSource agnostic (video, webcam, files)Format agnostic (BMP, JPEG, TIFF)Stack and adjust images as they arriveResult image accessed via web browser

Create Wi-Fi based control and imaging solutionWired Ethernet Servers - RS-232 & VideoConcentration - Wired Ethernet to Wi-Fi

bluetooth wireless telescope computer interface

Documents