USB Digital Setting Circles Schematic

The kit is much simpler than the serial version–the pull-up resistors were eliminated, the oscillator replaced by a crystal, and a MAX232 chip is no longer needed. The board and encoders are powered by the USB port, too, so no external power supply is needed. The kit includes all the components, including the programmed PIC chip, but does not include the TTL-232-5V cable. The cable must be purchased separately and is readily available from Mouser and Digikey, for about $20 plus shipping.

This kit should work great if you want to run your digital setting circles straight through the USB port of your laptop. However, if your goal is to use a bluetooth connection between your computer/PDA/smartphone and the board, then the serial version of the kit is the one you want to use. Furthermore, this USB version really isn’t adaptable for use with a smartphone or PDA–the TTL-232 USB cable needs to plug in to a PC in order to work.

Now it was time to get it all hooked up and functioning.

The BT232B adapter needs to be powered. There are three options:

1. a USB cable (only for power, not data)
2. an external 3V – 5V battery (not included, but a small cable and connector are included)
3. 5V at pin 9 of its DB9 connector

I chose option 3. Since my DSC interface board already has a 5V supply available, it’s a simple matter to feed it to pin 9 of the DB9 connector (note, however, that this combination will consume more than double the current of the DSC interface by itself, so you’ll want to use something bigger than a 9V battery to provide power). Here’s a photo of how I installed a small jumper wire on the underside of the board to provide the 5V at pin 9 (click to enlarge):

DSC board with jumper to provide 5V to pin 9 of the DB9

Be careful that the jumper wire doesn’t short with any other circuit board traces.

Once the board is providing 5V to pin 9 of the DB9, you’ll need to set a switch on the BT232B. There’s a switch that determines whether it’s expecting power on pin 9 or from the USB or external battery. Set the switch so that it expects power from pin 9. As a test, you can plug the BT232B into the DSC board (using the gender changer) and then power up the board. The BT232B Power LED should glow red, and the Status LED should flash blue.

The next thing you’ll need to do is configure the BT232B for 9600 baud, 8 data bits, 1 stop bit, no parity, and no flow control. The included instructions tell you how to do this, but the basic procedure is to set it for DCE (there’s a switch on the side to change it between DCE and DTE, depending on whether your plugging it into a computer or another device like the DSC board), plug it into a serial port on your computer (or through a USB-serial converter), give it power (the USB cable is convenient for that, but change the power selector switch), and then connect to it using Hyperterminal at 19200 baud, 8 bits, 1 stop bit, no parity, no flow control. you can then type commands in Hyperterminal that will change the configuration of the BT232B.

First, type “AT” (without the quotes) and hit the Enter key. The BT232B should respond with “OK” (again, without the quotes). If not, double check your settings and switches and try again.

Then type the following commands:

• PARITY=N
• FLOW=N
• BAUD=9600

After each command the BT232B should respond with some sort of confirmation of the command. However, after you set the new baud rate, Hyperterminal will no longer be able to communicate with the BT232B because the baud rate was changed. Don’t sweat it–you’ve done everything you needed to do.

Now you should be able to disconnect the BT232B from the computer. Set it for DTE and for getting power from pin 9 of the DB9, and plug it back into the DSC board, and power it up. If your PC doesn’t have built-in Bluetooth, you’ll need to insert your USB-Bluetooth adapter into a USB port (don’t forget to install any drivers if needed–check the documentation).

Now turn on Bluetooth on your PC and connect to the BT232B. Usually this is done by right-clicking on a Bluetooth icon in the system tray and selecting Connect from the menu. Windows will search for nearby Bluetooth devices and give you a list from which you can choose the serial Bluetooth adapter. Once it’s connected, it will hopefully report which COM port it’s configured as. If not, go into the Device Manager (right-click on My Computer in the start menu and select Properties from the context menu) and look at the list of ports to determine which port number is assigned to the serial Bluetooth adapter.

If you want, you can use Hyperterminal to connect to that port (9600 baud, 8 bits, 1 stop bit, no parity, no flow control) and test the connection. Once Hyperterminal connects to the port successfully, the flashing blue LED on the BT232B will stop flashing and glow steady blue. Try typing “H” and “Q” (without the quotes) and see if you get a response from the interface. If not, go back and double-check your steps and try it again.

Now you’re ready to use your favorite astro software with the DSC interface via Bluetooth. Just make sure that you set the COM port in the Settings to be the one for Bluetooth.

Let me know how it goes.

I even printed out some log and dupe sheets and dug out my old clipboard. I noticed the clipboard still had a square of hook-and-loop material that I used to use to hold my old Handspring Visor PDA in place for logging. Ten years or so ago, I wrote a Palm contest logging application that I named GOLog, and I designed and constructed a companion device I called the Serial CW Sender that interfaced GOLog to my transceiver to handle contest keying. All in all, it was a pretty neat system. Its chief drawback was that data entry on the Visor (and other PDAs, for that matter) was pretty awkward–you either used Graffiti or the onscreen keyboard. While it’s true that you could buy nifty fold-up keyboards for these PDAs, it wasn’t possible to use a keyboard and the Serial CW Sender at the same time, since they both wanted to occupy the single serial port on the Visor. I did, however, pick up a Targus keyboard at the time so that I could make sure that GOLog would work with a keyboard (GOLog could be used with or without the Serial CW Sender).

I hadn’t used my Handspring Visor in years, and since I bought my new notebook computer six months ago, I didn’t even have the Palm Desktop synchronization software running on any of my computers. I wondered if I could even still use this stuff–after all, the hardware is more than ten years old. So, naturally, I gave it a shot.

Palm Desktop is still available for download from Palm’s website. It turns out that Palm Desktop won’t run properly on a 64-bit Windows 7 computer, so that eliminated using my new notebook. Instead, I installed on my MSI Wind netbook running 32-bit Windows 7. Palm Desktop runs like a champ on that platform.

My Handspring Visor is the original Visor Solo, and it came with HotSync cables for both serial and USB. Once I got Palm Desktop installed and running, I connected my Visor to the netbook using its USB cable and initiated a HotSync on the Visor. Much to my surprise, Windows 7 found a driver for it and installed it! I thought for sure I’d have to go hunting for a driver for the thing.

I wasn’t out of the woods yet, though. The HotSync process kept causing a fatal exception on the Visor. Apparently the Palm Desktop software was trying to sync with an application that didn’t exist on the Visor. I fixed this by turning off synchronization of all the apps. It would then HotSync, but nothing was being transferred. (Later I went back and enabled selected applications for synchronization–it’s safe to enable Date Book, Address Book, To Do List, Memo Pad, Install, and Backup. Enabling Package Installer caused the Palm to lock up, so leave that disabled.)

Next I re-enabled the application installation feature so that I could at least install the GOLog application, and that went without a hitch. GOLog was up and running on the Visor, but it’d been so long since I used the software that I had to consult the user’s guide (that *I* wrote) to remember exactly how to set up for a contest. So far, so good.

I had no intention of using the Serial CW Sender, but I thought I might try the Targus keyboard to see how that’d work for Field Day. Miraculously, I still had the CD containing the installer for the Visor keyboard driver. The installer wouldn’t actually run–it said it couldn’t locate the executable for Palm Desktop–but the driver file itself was located on the CD and was easily installed manually. Once I figured out that I had to reset the Visor before the keyboard would work, everything was up and running!

The last test was to see if GOLog would properly synchronize with Palm Desktop. When I wrote GOLog, I also wrote a conduit that transfers GOLog’s log files from the Visor to the PC as a text file. Thankfully, the conduit worked like a charm, and I was able to get a sample log off the Visor and onto the PC. All was set!

My first opportunity to try the system under actual contest conditions was the monthly Spartan Sprint, conducted by the Adventure Radio Society. While the Spartan Sprint doesn’t offer anywhere near the activity of Field Day, it did give me enough to shake down the setup and assess it for Field Day use. I managed about 10 contacts in an hour or so, with no surprises from the equipment. The keyboard made it a breeze to use the Visor for logging, and GOLog did a great job of handling logging and dupe-checking. Since I operate in search-and-pounce mode during Field Day, I wouldn’t really miss the Serial CW Sender’s ability to handle the contest keying.

One of the best thing about the Visor and other old monochrome LCD PDAs is that you can run them for an entire weekend on a couple of AAA batteries. This is a definite contrast to more modern color devices that drain batteries pretty quickly. Also, with the Visor, you can swap batteries in the field if needed. Almost all modern devices use rechargeable batteries that are built-in and can’t be changed. In this case, older technology is definitely better suited for my needs.

So I’m all set for Field Day, at least for my radio gear. No one will be able to accuse me of running the latest and greatest stuff. I’ve definitely turned the calendar back about ten years or so.

Up until now, I hadn’t really given that antenna a good workout. But last weekend was Field Day, and this year I had to settle for working Field Day from the shack. Sadly, I was disappointed by my antenna’s performance. Although I managed to work 50 QSOs in four or five hours, I struggled to hear and contact other stations, even when running 100W. The noise level was very high, and signal levels were underwhelming. I worked only two SSB stations, the rest being CW contacts. It was time to rethink my antenna situation.

Up to now I’d ruled out a dipole or similar antenna because I had no trees to support one. I hadn’t really considered using the house itself (it’s a two-story) to support a dipole. The house is wood-frame construction with wood siding, so having an antenna wire running along the side of the house shouldn’t be too bad, I figured. I decided it was time to experiment.

One of my favorite antennas is a half-size G5RV (I suppose a full-size one would be my favorite if I’d ever had enough space for one). My main HF antenna at my previous QTH was a half-size G5RV in a vee configuration supported about 25 feet up at the center by an aspen tree. And when I take my ham station out to the field, my main antenna is usually a half-size G5RV constructed with twinlead and lightweight wire–the entire antenna fits into a gallon freezer bag.

I did a little measuring and came to the conclusion that I could get a G5RV up about 20 feet if I used the side of my house to support it. The feedline could run up the back corner of the house. One leg would run along the side of the house from the back to the front, and the other leg would run through the air toward the back corner of my property and be tied off at the privacy fence. But would it work?

It took about an hour of time to put up the ladder and add some small hooks in strategic places on my house (hoping my neighbors wouldn’t get too nosy about what I was up to), and I soon had rigged a system that would allow me to easily hoist my feedline and wire legs up the side of the house and lower them again. I got everything rigged up, hoisted up, and connected up, and I went into the house to fire up the radio. I didn’t know how the antenna would tune up in a less-than-ideal configuration, but I was pleasantly surprised by what I heard. This configuration beat the vertical hands-down! Noise levels were lower and the signal strength was much improved, and the antenna tuned sufficiently on every HF band except 30 meters.

My installation was far from stealthy, though. While the feedline and the leg on the side of the house were difficult to spot from the street, the leg running through the air in the back yard stuck out like a sore thumb–both the wire and the string supporting it were clearly visible. And since I wanted to save this antenna for portable work, I knew I’d have to rebuild it using a more stealthy approach. So I ran over to my favorite junque store and acquired some light-beige-colored 26-gauge stranded wire, and a stop at the sporting goods store yielded some nice invisible monofilament fishing line. I rebuilt the antenna using some extra twinlead I had laying around, hoisted everything back up, and tested again with the same happy result. And now the back leg of the antenna, while still visible, is much less noticeable. Hopefully, my neighbors won’t notice that any more than the vertical that I’ve since taken down.

Up to this point, hamming from this QTH has been a struggle. Hopefully this antenna will restore more of the fun. Tonight is the Adventure Radio Society’s monthly Spartan Sprint. I’ll let you know how the antenna performs.

Here’s one for starters:

If you know of any other good soldering tutorials and resources, leave a comment below.

I consulted with the smart guys on the AMSAT-BB mailing list, and the general consensus was that I would indeed need a preamp for best results. And then I read the last paragraph in the QST article:

On the downlinks, a low noise (1 dB NF) preamp mounted at the antenna was employed.

Duh. So, last week I ordered a 70 cm low-noise preamp kit from Down East Microwave. I’m looking forward to assembling it and trying it out as soon as it arrives. And while I’m waiting for it to arrive, I’ll be trying to repair my Samlex SEC-20 power supply. It went kaput last week. Luckily, Samlex tech support was kind enough to send me a schematic, parts list, and some troubleshooting info (let me know if you’d like a copy).

At any rate, I’ll update you on the Lindy and the preamp as soon as I have something to say.

So last weekend I was at the local Ace Hardware store with a list of parts in my hand. This list included items like:

• 1/2″ x 1/2″ gray PVC insert connector
• 1/2″ x 1/2″ gray PVC insert-to-threaded adapter
• 12″ x 1/2″ threaded gray PVC riser
• 5″ x 1/2″ gray PVC ferrules for spacing rain gutter nails
• 1/8″ aluminum tubing
• conductive grease

Some pretty obscure stuff, eh? I wasn’t having much luck finding the ferrules, so I enlisted one of the employees (an older guy) for some help. I showed him my list, and he squinted at it for a moment. Then he turned to me and asked, “Are you building an antenna?”

I laughed, “Yeah–how’d you know?” He chuckled and replied that another guy had been in the store recently with the same list. What are the odds of that? At any rate, he helped me round up the rest of the parts I needed, and construction begins today. I’ll post again with the results of the effort and my impressions of its performance.

I certainly made things interesting for myself last week when I purchased a 2007 Pontiac G6 GT hardtop convertible. It’s quite a car–200-hp 3.5L V6 (not overwhelming, but adequate), power everything, heated leather seats, awesome Monsoon sound system with XM radio and a 6-CD changer–it’ll be nice and comfy for my half-hour-each-way daily commute.

Any mobile ham radio installation in a modern vehicle presents challenges, and this car has them in spades. Things are a little easier with today’s crop of rigs where the front panel separates from the rest of the radio (meaning a smaller box to find a place for around the dashboard), but there’s still the problem of locating the rest of the radio, routing cables, placing speakers, and slapping an antenna someplace.

Now, don’t think for a moment that I’ve solved any of these problems yet. I’m still cogitatin’ on every one of these issues. Probably the first thing I started to think about was where to put the antenna. I normally favor a trunk lid mount. But watch this video of the roof retracting into the trunk:

(Is that cool, or what?) You can see that, at the very least, routing the antenna feedline needs to be well-thought-out. And when the top’s down, there’s very little room in the trunk, so it may not be possible to mount the radio body back there. On the plus side, there’s a fuse box in the trunk, so it might be possible to draw power from it for the radio if I can find a place to mount the radio back there.

Another challenge is getting the rig’s audio into the passenger compartment. On almost all mobile rigs, the speaker is contained in the radio box rather than the control head, so if the radio box isn’t mounted inside the passenger compartment, you’ll need to mount a speaker for the audio, or perhaps make use of an aux input to the car’s sound system. In my case, the Monsoon sound system doesn’t have a built-in aux jack, but I found a cool little add-on unit from PAC Audio that interfaces directly with my sound system to provide an iPod input as well as an aux input (or HD radio input). Installing this particular unit (at least in my car) requires removing dash panels and the radio, but the result is a seamless integration with the existing sound system. I’m seriously considering one of these just for the iPod interface. You can get this unit with the appropriate wiring harness for about $130 from several places on the web–much better than the $169 MSRP from the manufacturer. Other manufacturers make similar devices, such as Axxess Interface. Another option would be to use one of the FM transmitters on the market for playing the output of MP3 players on your car radio, but they don’t appear to work that well. And any solution that plays the rig’s audio through your car sound system makes it impossible to listen to the car stereo and monitor your rig’s audio at the same time.

So I’m nowhere near actually installing a rig in my new car at this point, and I’m not even sure whether I will install a rig. It’s a pretty sweet-looking car, and I don’t want to junk it up with a less-than-optimal installation job. If I can find a way to integrate a rig cleanly into the car (and be able to take it out again without leaving any residual effects), I may go ahead and do it. If I do, I’ll be sure to post about it here.

]]> http://eksfiles.net/2010/01/new-ride-new-radio/feed/ 0 http://eksfiles.net/2009/05/sena-bluetooth-adapters-with-digital-setting-circles/ http://eksfiles.net/2009/05/sena-bluetooth-adapters-with-digital-setting-circles/#comments Mon, 25 May 2009 15:07:31 +0000 Dave http://blog.eksfiles.net/?p=202 Eddie from Australia wrote me recently to tell me about his success using a serial-to-bluetooth adapter to connect his Digital Setting Circles board to his laptop (avoiding the serial cable which is an obvious tripping hazard, especially in the dark during an observing session). Eddie is using the SENA Parani-SD 200 serial-to-bluetooth adapter connected to the DSC board, and the SENA Parani UD100 USB-to-bluetooth adapter with his laptop.

Eddie wrote:

Dave,

I have finally managed to get the Bluetooth connection working with your interface and Cartes du Ciel. I will let you know what I had to do and the setup I’m running so that you can let other people know if you get asked the question.

Program: Cartes du Ciel
Serial Bluetooth adaptor: Sena Parani SD200
USB Bluethooth adaptor: Sena UD100

Information for the Bluetooth adaptors can be found on www.sena.com

You have to plug the SD200 into a computer with a serial port in order to set up the adaptor. The adaptor gets set to mode 3 with command response set to on. Using the Dip switches on the SD200 the Baud rate and flow control can be set to 9600 and off respectively, the other parameters are set at the factory and cannot be changed. When connecting the Bluetooth adaptors the UD100 will need to be forced to operate on one of the local com ports i.e. 1,2,3…. etc so that it can work with your interface.

Then I had to make up a null modem serial adaptor between your interface and the SD200 adaptor. Pins 2 and 3 have to be crossed over in the connector and 5 is straight through. Cartes du Ciel doesn’t like handshaking and therefore the remaining pins must be left off or the tracks on your PCB have to be cut.

Once all of this is done your interface works very well and the laptop can be setup remotely from the scope so that wires aren’t being tripped over or having to attach your computer to the scope itself.

I hope that this information will help you and any other Astro nuts out there setting up their interface with a Bluetooth connection.

Thanks, Eddie, for passing on that information.

I’ve heard of other users who’ve successfully used similar devices, especially those from AirCable. I don’t have any personal experience with any of these devices, but they’re an occasional topic of conversation in the Yahoo Groups’ PalmAstro group. I’d welcome any and all reports of other bluetooth adapters being used with my DSC system–just leave a comment below.

If you’ve used another enclosure and liked the results, leave a comment below and tell me about it.