Putting the "Ek" in "Geek"
Digital Setting Circles
Test Software for Digital Setting Circles Project
Dec 27th
I’ve written a small program called EkBoxTester that you can download to aid in testing your Digital Setting Circles interface board after you’ve constructed it. EkBoxTester requires Microsoft .Net 4.0 to be installed on your computer. EkBoxTester consists of a single executable file (EkBoxTester.exe) that can be run from wherever you want. There is no installer–just download and run it.
The source code for EkBoxTester can be downloaded from here. It was written using Microsoft Visual C# 2010 Express Edition–a free but reasonably complete development environment for writing .Net applications in C#. You can use the source code as an example of how to communicate with an EkBox via the serial port.
USB Digital Setting Circles Kit!
Dec 18th
FAR Circuits has just released a kit for a USB version of my Digital Setting Circles project. The USB version relies on the FTDI TTL-232-5V interface cable as shown in a previous post. A complete writeup is now included on my USB Digital Setting Circles page. Here’s the schematic for this new kit:
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.
Cheap(er) Encoders for Your Digital Setting Circles
Sep 13th
One thing that puts people off when they consider building their own digital setting circles is the cost of the two rotary encoders that are needed. Building my DSC circuit is fairly inexpensive (maybe $30 or so), but a pair of high-resolution optical encoders can set you back to the tune of $150 or so. Recently, someone posted information about these capacitive encoders on the Palmastro Yahoo! group. Apparently, they work well in digital setting circles applications, and they appear to be electrically compatible with optical encoders. The spec sheet says they’re accurate to 15 arcmin, which is probably good enough for most users. The best part? You can have a pair for about $50. Digi-Key is supposedly a source of these babies.
Bluetooth Adapters for My Digital Setting Circles
Jun 19th
I was finally motivated to get my hands on some Bluetooth hardware so I could figure out why my latest ASCOM driver wouldn’t work with Bluetooth. I found mine at U. S. Converters. I needed two–one that would plug into a USB port on my notebook (I bought model BLDONG for $9.99), and one that would plug into the serial connector of my digital setting circles interface (BT232B for $45.00). The BT232B serial Bluetooth adapter also requires a gender changer because it has a female DB9 connector just like my DSC interface, so I bought 10GC-D1 for $7.99, too. I know that AirCable sells this kind of stuff, too, but U. S. Converters seemed a little more economical.
Now it was time to get it all hooked up and functioning.
Bluetooth DSC Systems Available
Nov 11th
Craig Combes just posted this to the PalmAstro Yahoo Group (note that you’ll need to be a member, or become a member, in order to follow the link and see his picture):
Hi Guys,
I came up with a newer board that fits nicely in a roughly 3 3/4″ x 2 3/8″ x 1″ enclosure that has a space for a 9v battery. So I have some complete systems that I’m selling for $100, and that includes some encoder connectors. I’ve uploaded a photo here: http://groups.yahoo.com/group/Palmastro/photos/album/710692234/pic/listCraig Combes
Earlier this year Craig sent me a description of his bluetooth DSC system which I added to my Digital Setting Circles pages. Go there for a full description. Contact Craig directly if you have questions or want one of his systems.
Bluetooth Digital Setting Circles
May 31st
Craig Combes has taken my Digital Setting Circles project and adapted it for bluetooth! I’ve added his project description to my Digital Setting Circles pages. You can see it here.
Thanks, Craig!
Soldering 101
May 8th
For a surprising number of folks, my Digital Setting Circles project is their first introduction to electronics construction techniques–mainly, the art of soldering. If you’ve never seen it done correctly, soldering can be an intimidating prospect. Someone asked me the other day whether there were any YouTube videos of someone constructing my project (none that I know of). That got me thinking–there must be plenty of “how to solder” videos around. So I checked, and sure enough, YouTube has quite a few of them.
Netbooks for Astronomy?
Oct 18th
Being a techie kind of a guy, you’d think I’d be more abreast of the latest in computer hardware and gadgets. But up until a few months ago, I was pathetically unaware of the new class of computer hardware known as the netbook.
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.
SENA Bluetooth Adapters with Digital Setting Circles
May 25th
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.
A Box for the Digital Setting Circles Board
May 25th
A question from a builder of my Digital Setting Circles project caused me to notice a plastic enclosure that another builder had used to contain the circuit board for that project. Oscar’s web page gives a nice narrative on how he built my project, and this page shows a nice enclosure with a clear plastic top he used for the project. The box came from Jameco, and it appears to be part no. 141832. Make no mistake–you’ll have to cut holes in the sides for the serial connector, encoder connectors, and battery connector, but at least the box is about the right size and looks to be easy to work with. I’m sure there are other suitable enclosures out there, as well.
If you’ve used another enclosure and liked the results, leave a comment below and tell me about it.
