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Virtual Comm Port …pitfalls, and crazy mouse

IMG_0737Well here we are in 2012, and navigation equipment manufacturers still don’t know that laptops don’t have serial ports anymore. If you want NMEA data fed from your instruments into your chart plotting software you are forced to use USB/serial port converters. This means that you will need to create what’s called a virtual comm port and that in turn needs a special software driver. This is when the fun starts.

Whatever you do don’t but any USB / Serial converters that use Prolific software drivers. Don’t do what I did and ask for or shop for “Windows 7 compatible” converters – that is not enough. Prolific are a good company but unfortunately for them it appears that there are a lot of cheap Chinese converters on the market with hacked Prolific IC’s and useless software drivers that simply do not work…

Here is the warning on the Prolific website: “Please be warned that counterfeit (fake) PL-2303HX (Chip Rev A) USB to Serial Controller ICs using Prolific’s trademark logo, brandname, and device drivers, were being sold in the China market. Counterfeit IC products show exactly the same outside chip markings but generally are of poor quality and causes Windows driver compatibility issues (Yellow Mark Error Code 10). We issue this warning to all our customers and consumers to avoid confusion and false purchase.”

Go for converters that use the FTDI chip set and matching software drivers. The one that I have gone for is the Startech.com FTDI USB to Serial RS232 Adapter Cable with COM Retention. This works perfectly with Windows7 and also as the name implies always comes up with the same comm port number when you re-use it. This helps with configuring chart plotting software to always look at the same comm pot on each use.

There is still something waiting to bite you however. Do you remember “crazy mouse”. That was when the operating system decides that your USB/Serial converter is a mouse – and your cursor and mouse pointer starts careering all over the screen launching program at random. I thought those days were over – until today!

For no apparent reason the perfectly working USB/Serial converters (I have two of them plugged in) were suddenly identified by Windows 7 as a “Microsoft wheel mouse”….and off it went – crazy mouse all over again – I couldn’t believe it! I realise that it is the stream of NMEA or GPS data that gets interpreted by the Windows as mouse data – but really – it is not beyond the wit of man to work this all out…well I guess it is beyond the wit of some programmers at Microsoft.

The solution in my case was to let the crazy mouse happen – unplug the converter (you get mouse/track pad control back then) and immediately go into Device Manager and “Disable” (right click) the erroneous “Microsoft Serial Ball Point” device listed. Generally I tend to boot the laptop with the USB/serial convertor disconnected; wait until all the drivers are loaded and the laptop is just idle (3 mins); then connect the USB/serial convertors. I also recommend creating a shortcut to “device” settings on your desktop – you will be in and out of these a lot checking on the virtual comm port drivers!

If the technique above doesn’t work for you, then I recommend reading this document from Jeppesen; or from CAP’N; or from  Coastal Explorer…and trying the techniques described there.

Good luck!.


Using light instead of electricity…

USG1A422-150exThe innovative Actisense USG-1-485 can be used to protect your laptop from sudden voltage spikes while connected to your boat’s serial wiring system. The traditional NMEA 0183 is often offered as a serial port connection when most modern PC’s and laptops only have USB nowadays.

Up till now all you had to do was buy a suitable Serial/USB convertor such as the one I reviewed here, or buy a multiplexor such as the one I reviewed here.

This device does it differently – light is used to transfer the data signals between the serial port and the USB. The device gets its own power from the laptop’s USB port. Installation is easy using the supplied CD that will create a “virtual serial port” on your laptop.

The only problem is the price …£80!


Electronic Navigation – New System

This is my new system..
– GPS Raystar 125 (2nd GPS)
– Chart plotter – C120
– AIS (outputting at 38400 to Brookhouse and then to the C120)
– Raymarine 18″ 2Kw Radar

Connecting to a laptop
– ACER Aspire 5022WLMi

– E85001 – NMEA0183/Seatalk I/f box to output NMEA0183 to serial and then via a serial to USB adaptor into the laptop

– Brookhouse Multiplexer to I/f AIS to C120 at 38400 and to output on its built in USB cable straight into the laptop

This means that two independent programs can operate on the laptop both getting data in from the ships instruments

All of this now works well after many hours of head scratching and torn knuckles 😉


Electronic navigation – Old System

I have upgraded the electronics on Enterprise and I now have two almost separate navigation systems (backup before resorting to charts !)

Firstly there is the ‘old’ system – now 11 years old..
– Raymarine GPS
– Autohelm ST50 instruments (log, wind, depth, multi)
– Phillips navigator Mk8
– Autohelm autopilot 3000 (wheel based)
– All connected on a Seatalk bus

DSC00003The Philips navigator is really good. Its visible under the spray hood, and is always pretty much in agreement with the new system (all Raymarine based) that I run in parallel. Since the cockpit is small I had no room for a new Raymarine screen on the helm – never mind the cost! – so I put the new Raymarine C120 at the chart table and use my trusty old Phillips navigator in the cockpit.


USB to Serial Adaptor

If you search the forums you will see some references to difficulties in using serial to USB adaptors on a PC or laptop. Issues are described where Windows treats the adaptor as if it were a mouse, comm port conflicts, baud rate errors and so on.

USB adaptorI searched for a suitably qualified company that would use drivers that the ‘experts’ say are reliable and eventually bought two serial to USB adaptors from Easysync .

I can report that the products have worked flawlessly on my laptop (Win XP) and I have had no comms issues at all.

Of course it is still advisable to keep a shortcut on the desktop that takes you straight to the ‘System’ settings of Control Panel – because software you use will reconfigure your nicely configured virtual comm ports when you least suspect it …but it is obvious when that happens and easy to put right – this is not the fault of the adaptors.

The main points to note are:

1 – these adaptors work
2 – the virtual comm port drivers are from FTDI and they work
3 – there is a generous FIFO buffer of 128 / 384 bytes
4 – They have xmit/rcv lights so you can see whats going on!

The following is taken from the suppliers web site..

* FIFO: 128 byte transmit buffer 384 byte receive buffer
* Enhanced RS232 transciever gives serial port speed of up to 500K bps – this is faster than most and will help to avoid any further speed issues.
* Adds one RS-232 serial port by connecting to USB port
* Installed as standard Windows COM port
* Works with USB 1.1 & 2.0 host port
* One DB9 male connector
* Serial Communication Parameters
-Parity: None, Even, Odd
-Data bits: 7, 8
-Flow control: RTS/CTS , DSR/DTR, X-ON/ X-OFF, None
* RxD, TxD LEDs for monitoring port status & easy diagnostics
* integral 1m USB cable with moulded strain relief
* Quality 4-layer pcb design
* COM Port Number can be changed to COM1 to COM4 to support HyperTerminal, or any other COM port number required
* Industry Standard FTDI chip set & drivers for maximum compatibility
* Supports Windows XP, 2003, 2000, ME, 98, Linux, MAC-OS8,9,X
* Full RS-232 modem control signals
* RS-232 data signals: TxD, RxD, RTS, CTS, DSR, DTR, DCD, RI, GND
* Powered by USB port. No external power adapter required.