Thanks, Craig!

Here’s one for starters:

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

If you’re using this new driver, please leave me a comment below and let me know.

I’ve been working on an updated ASCOM driver for my digital setting circles project for quite some time now. Yeah, I’m slow. At any rate, it’s just about ready for prime time, but I could use some beta testers to give it a whirl. (See below for a link to the download.)

What’s new, you ask? Well, I rewrote the thing, basically. It still bears some resemblance to the old driver, but it also now includes syncing and slewing capabilities, and an upgraded interface for performing the alignment process.

The picture above is of the alignment screen. Instead of being presented with a list of stars like before, you can now select alignment stars graphically by constellation. Hopefully this will streamline the alignment process.

The next picture shows the screen that appears when you tell your software to slew your telescope. Obviously, your telescope will not magically grow motors for slewing. The screen gives you visual feedback as you manually push your telescope tube toward your intended target. You push the tube until both numbers read zero, at which time your telescope should be pointing at your target.

This picture shows the setup dialog for the new driver. It’s not much different in content from the old driver, with the exception that there is now a checkbox for reversing the altitude encoder ticks. You should not check this box until you have found that no other combination of settings will result in a successful alignment. If the old driver has worked okay for you, you will not need to check this box.

You can download the new driver installer here. You can have both the old and new drivers installed at the same time, so make sure you select the correct one in the ASCOM chooser dialog box. If you need a refresher on ASCOM, visit my project’s compatible software page.

Please leave a reply below if you have any questions, comments, or suggestions regarding this new driver. I’ll be releasing a final version of the driver sometime in the next couple of months, after I’ve fully tested for compatibility and written some help files.

Netbooks first popped up on my radar screen when I stumbled upon an article describing how somebody was successfully running Mac OS X on theirs. That was (and still is) intriguing to me–OS X is supposed to be pretty slick, but I’ve always been put off by the Mac price tag. But I digress.

One of the attractive things about netbooks is they’re cheap. My MSI Wind U100-843 with 2GB of memory and a 160-GB hard drive ran me about $300. After having it for a few weeks now, I’m impressed with it. It runs Windows XP Home SP3 like a champ. The netbook itself is built well, and the battery supposedly will give me six hours of operation (I haven’t really tested this yet, though). It’s quick to boot, has a great display and a decent touchpad, and wireless connectivity has been solid. In short, everything works. That’s not a given with PC hardware these days, so it’s nice to experience it.

One of the things I didn’t really consider before I bought my netbook was whether it would be handy for use with my Digital Setting Circles project and a telescope. The netbook has no serial port, of course, so I’d have to use a USB-serial converter to plug the digital setting circles into my computer. A while back I picked up a really cheap converter on Ebay, and I figured this would be a good test. So, I loaded up TheSky 5, the ASCOM platform, and my own ASCOM driver and put the system through its paces.

There was no reason to think that the system wouldn’t work, and I was right–everything worked flawlessly. Even the el-cheapo USB-serial converter did its job magnificently. (For the life of me, I don’t understand why these converters have gotten such a bad name. I’ve never had difficulty with one. And a lot of USB devices make use of them internally so that separate USB drivers don’t have to be written for those devices.)

I originally designed my digital setting circles project to be used with a notebook computer, but many folks these days are using it with a PDA or smartphone because of the portability of such devices, the availability of software for them, and the fact that they often support bluetooth for wireless connections between telescope and computer. Still, handheld devices are definitely a compromise of power and versatility for convenience. Netbooks are now in a price range comparable to these handheld devices and provide nearly the same convenience of portability while being vastly superior in capability. I could easily envision using the netbook with my digital setting circles while simultaneously using it to control a digital imaging system and log my observing session–a tall order for a handheld device.

The handheld device landscape has shifted dramatically over the past few years. While PDAs running Palm OS and Windows Mobile once ruled the land, they’ve been largely obsoleted by smartphones like the iPhone and the Palm Pre. While software developers are catching up to the new platforms, one needs to actually own a smartphone (with its higher costs for broadband service) in order to use the software. Handheld alternatives to smartphones are disappearing fast. Netbooks don’t carry the extra baggage of requiring a monthly payment for cellular network access (unless, of course, you purchase one from a cellular carrier for precisely that purpose).

I know many people who love their iPhones, but right now I’m too cheap to pay for being connected to that degree. Maybe I’m just an old curmudgeon. In a couple years I’ll probably be an iPhone-wielding drone just like everyone else. In the mean time, I gotta go see if I can find that article on how to turn my netbook into a Mac…

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.

Jimbo Harris actually adapted my decoder circuit to USB using a special cable from DLP Design. Jimbo was able to eliminate the MAX232 chip and the DB9F connector that way, but the net cost of the circuit was probably higher despite eliminating those parts. All the special cable really does is to make the USB port look like a serial port to the computer. There are plenty of commercial devices on the market that will do just that.

I’ve been told that USB-to-serial converters vary in terms of how well they work, which I find surprising. As far as serial interfaces go, the one in my decoder circuit’s about as simple as they come. It only runs at 9600 baud and only uses three serial lines (TX, RX, and GND) because it doesn’t use any hardware handshaking. There’s no twiddling of the lines at the hardware level. It really can’t get any simpler. It seems like, if a USB-to-serial converter works at all, it should work with my decoder circuit.

Are you using one of these USB-to-serial converters with my DSC circuit? Or perhaps with something else? If so, please leave a comment below and tell me about your experience. I’m going to experiment for myself here shortly–I ordered a $6 converter from Ebay (it’s hard to get cheaper than that, eh?) that I’ll try and post my results. And maybe I’ll consider doing a long-overdue update to my decoder circuit (but don’t hold your breath–it’s really hard to find the time for that kind of project these days).

Jim wrote to me:

Hi Dave,

The TTL232 modification was a success; I connected to the board in place of the MAX232 at pins:
+5v – pin 16
GND – pin 15
Tx – pin 11
Rx – pin 12
(all corresponding pins of the MAX232), and I left out the MAX232, 7805, and all the corresponding caps, etc. The interface booted right up. I connected via both your program and also via the ASCOM driver (in ASCOM Validator and in DSLR Focus). I got the same results both ways.

Here’s the marked-up schematic that Jim sent me:

Jim also sent me a photo of the TTL232R kit:

And here’s a picture of his connection of the TTL232R to the interface board: