Serial Port Alternatives

Newer model notebook and desktop computers may not come with a standard DB9 RS232 COM port. However, to be controlled by external software, such as TheSky or TheSky Pocket Edition, virtually every commercial telescope sold today requires RS232 serial communication.

There are several hardware solutions to this issue, including:

• Bluetooth Adaptors

• Serial-to-Ethernet Adaptors.

• USB-to-Serial Adaptors

USB-To-Serial Adaptors

Macintosh and Windows computers use USB ports instead of the older model DB9 serial ports. However, most astronomical devices require the standard RS232 serial interface.

So how do you connect a serial astronomical device (such as a telescope or focuser or filter wheel) to a computer with no RS232 serial port? Just purchase a USB-to-Serial adapter.

There are many different manufacturers of these adaptors, and not all work the same. The table below lists several different model USB-to-serial adaptors, with comments about compatibility.

USB Extension Cables

If you need additional length for your USB connections, consider purchasing a USB Active Extension cable (sometimes called a USB Repeater cable). Search www.google.com for "USB Active Extension Cable" to locate retailers of these products.

Serial-To-Ethernet Adaptors

A second solution to the "lack of serial port on a computer" problem is to use a Serial-To-Ethernet adaptor. Several manufacturers offer this hardware, which also offers almost unlimited number of "virtual serial ports" for connecting serial devices to your computer.

Manufacturers

Moxa Technologies

B&B Electronics

Digi Connectware

Bluetooth Serial Adaptors

TheSky6 and TheSky Pocket Edition customers report success using wireless Bluetooth® technology to control their telescopes.

Minimum System Requirements

Windows to Bluetooth Device

Windows Mobile Device to Bluetooth Device

Minimum System Requirements

The table below lists the minimum system requirements for a Windows computer, and a Windows Mobile device.

Windows Bluetooth Connection

Step 1: Configure the Bluetooth USB Adaptor using your Windows Computer

Follow the manufacturer's instructions for installing and configuring your USB Bluetooth device. This device allows the personal computer to communicate with other Bluetooth devices. Use Windows Device Manager to determine the COM port number of the device; you'll need it to configure TheSky6.

Step 2: Configure the Bluetooth Serial Adaptor for your Telescope

Use the configuration software that comes with your Bluetooth serial adaptor hardware to configure the adaptor to use the required serial port settings for your telescope. The adaptor must be programmed to use the correct baud rate, data bits, parity, and stop bits for your telescope.

In general, the adaptor's port settings are the only settings that matter. You may wish to add a security PIN, otherwise, the other configuration settings can be left to the default values. See the Autostar example below.

Step 3: Connect the Hardware

Connect the telescope cable (with pins 7 and 8 tied together) to the Bluetooth serial adaptor.

Step 4: Establish Communication

From TheSky6, configure the COM port of the USB Adaptor, and then click Telescope | Link | Establish.

Windows Mobile Device Bluetooth Connection

Step 1: Configure the Bluetooth Serial Adaptor for your Telescope

Use the configuration software that comes with your Bluetooth serial adaptor hardware to configure the adaptor to use the required serial port settings for your telescope. This is performed from your notebook or desktop computer. The adaptor must be programmed to use the correct baud rate, data bits, parity, and stop bits for your telescope.

Step 2: Connect the Hardware

Connect the telescope cable to the Bluetooth Serial Adaptor.

Step 3: Configure the Windows Mobile Device's  Bluetooth Interface

Make sure that Bluetooth is enabled on the Windows Mobile Device (see the device's instruction manual for details). Then, tap Start | Settings | Connections tab | Bluetooth. On the General tab, tap Bluetooth Manager. The first time the Bluetooth Manager is run, the Connect Wizard displays the connection options. Scroll down to the Explore a Bluetooth Device option, and then tap Next. The Bluetooth Serial Adaptor should appear in the list of devices to explore. Select it, and then click Next until the device setup is complete. On the Bluetooth My Shortcuts window, tap and hold the stylus on the socket serial port text until the pop up menu appears, and then tap Connect. This step should be performed before attempting to establish a wireless connection between TheSky Pocket Edition and the telescope.

Step 4: Establish Communication

From TheSky Pocket Edition, configure the COM port of the USB Adaptor (usually COM7), and then click Telescope | Link | Establish.

Example Socket Bluetooth Adaptor Hardware and Software Settings for Autostar

The list of settings below is specifically for the Socket Bluetooth Adaptor, and will allow TheSky Pocket Edition to control the Meade Autostar. Different model Bluetooth adaptors and configuration software should have similar settings.

Device Role: Acceptor

General Tab

* Friendly Name: Any Name

* Class of device - Unclassified

* Service Class - None Selected

* Service Name - Socket Serial Port

Connection Tab

* Connectable and discoverable

* Do not generate notification

Security Tab

* None

Port Settings Tab

Bits per second (baud rate): 9600

Data bits: 8

Parity: None

Stop Bits: 1

Flow Control: RTS/CTS (Required for the adapter to function.)

Advanced Tab

* Page Scan Timing:

-- Interval: 512 Slots

-- Window: 128 Slots

* Inquiry scan Timing

-- Inquiry: 512 Slots

-- Window: 128 Slots

* Sniff Mode Parameters

-- Sniff Mode Disabled

Example Socket Bluetooth Adaptor Hardware and Software Settings for Vixen SkySensor 2000

Click here to read the PDF documentation that describes how to connect TheSky Pocket Edition to the Vixen SkySensor 2000 via Bluetooth.

Thanks to D. Nardes who supplied this documentation.

Example Socket Bluetooth Adaptor Hardware and Software Settings for Takahashi Temma Mounts

See Connecting the Takahashi Temma to TheSky Pocket Edition via Bluetooth for a comprehensive, step-by-step procedure to control the Temma with TheSky Pocket Edition via Bluetooth..

Thanks to D. Nardes who supplied this documentation.

Simulating Hardware Handshaking

Many Bluetooth serial adaptors use "hardware handshaking" when emulating a serial port. This is a process where a request to send (RTS) data is sent, and the device responds with a clear to send (CTS) signal. Most telescopes (Temma mounts excluded) do not use hardware handshaking, so, it must be simulated in the telescope cabling.

For Bluetooth serial adaptors that require hardware handshaking, connect pins 7 and 8 on the DB9 connector of your telescope cable. Here's how (this procedure applies to telescope cables sold by Software Bisque only).

Required Items

• One small screwdriver.

• One Crimp and Poke F/F jumper cable.*

F/F Jumper Cable

1. Use the end of a small screwdriver to carefully pry the DB9 connector away from the gray housing.

2. Carefully rotate the DB9 connector so that the back side is accessible.

2. Insert one end of the jumper into pin 7, and the other into pin 8. Each hole on the connector is numbered (older eyes may need a magnifying glass to read them). Make sure to push both female connectors all the way in, without bending the small connector.

3. Making sure that the wires fit into the gray housing, snap the DB9 connector into the top of the gray housing.

Your telescope cable will now emulate hardware handshaking.

*Product Name: Crimp and Poke Female/Female Jumper, a package of 10 is about $2.00.

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