From: Milton Aupperle <milton@outcastsoft.com>

Date: July 21, 2012 3:36:14 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Re: Firefly MV cameras, NIB, on ebay

Yes you are missing a few things.

1) As I said, cables become rods at -30°C or colder. Fewer cables have less issues to deal with for guiding. And you have less tangle issues and less cable breakage too. Have a look at my old winter operating conditions:

http://www.outcastsoft.com/AstroImages/Scope04.jpg

http://www.outcastsoft.com/AstroImages/Scope05.jpg

That's 4 cables going to the mount form the Mac - now it's one cable.

2) ASCOM is not supported on the Mac - and likely never will be.

3) Pulse guide is not supported on HEQ5 / HEQ6 mounts - and I'm pretty sure not on Celestron in general. That's "faked in software" via ASCOM for those mounts. We already spawn individual preemptive threads for doing this anyhow.

4) The ST4 ports are simple switches and give direct access to the mount motors. No command interpretation needed by a slow Micro or FPGA. You can use two pieces of wire to move the mount around via the ST4 port.

5) USB to Serial port converters have very high latency rates (50 to 500 ms - we are talking 9600 baud communication) - as do the mounts micros that interpret the commands. With the GPUSB, the latency is in the 5 to 8 ms range for sending. With my GPIO to ST4 board over FireWire, the latency is 0.125 milliseconds (that's 125 micro seconds) between switching the motors on or off.

6) HEQ5 / HEQ6 and Celestron mounts in general have no means to move the mount arbitrarily. You can't just say "move 2 pixels left and 1 pixels down", one has to get the current location in RA/DEC and then send it a goto command to move it and wait for the response to be accepted (I have already gone through why the Celeston protocol will never work in the list) The only way to do this is via the ST4 port for those mounts.

7) Astro IIDC can issue up to 6 corrections per second via the ST4 port (assuming the frame rate is 30+ fps) and can send corrections on both axis at the same time. That simply isn't possible via serial ports and will require at GPUSB or better direct connect.

HTH..

Milton Aupperle

On 21-Jul-12, at 2:26 PM, Dave Goodyear wrote:

I have a question. Why would you use these devices? Just for st-4 output? Is there an issue using the serial port and ascom and pulse guide? Is this for single cable to mount if not using serial mount control? If your already going to have a pc close, whats an extra cable? Maybe i'm missing something?

Dave Goodyear

Sent from my iPhone

On Jul 21, 2012, at 9:43 AM, "Milton Aupperle" <milton@outcastsoft.com> wrote:

On a side note. you can also build your own ST4 Guider board and then

use that instead of the GPUSB : cost would be less than $10 for parts.

http://www.outcastsoft.com/AstroImages/GPIOtoST4_InterfaceV3_MJA.png

The FireFly MV and Chameleon has 4 GPIO pins via a BM07B-SRSS-TB

connector, so you could connect the BM07B-SRSS-TB to the ST4.

Then you have one cable to the camera, and the camera connects to the

ST 4 Port.

I use that all the time now. So I have one FW800 cable coming from my

Mac , which is connected to the Grasshopper 2 (it has 2 FW 800 ports),

and then I daisy chain a FW800 cable from the main imaging Grasshopper

2 to my guide camera (either a FW400 Flea or now my old Grasshopper 1

camera) and then the ST4 port is connected to the guide camera. So a

single cable to 2 Cameras and the mount for imaging, guiding and mount

control. For me, this is especially important during the winter to

reduce the number of stiff cables I have to deal with (at -40°C all

cables are basically plastic rods).

See page 109 and 110 of the Astro IIDC manual for more information on

Hardware modifications.

HTH..

Milton Aupperle

On 21-Jul-12, at 10:14 AM, doobisary wrote:

> You would connect the computer to the mount using a GPUSB from

> Shoestring Astronomy. They're reasonably priced, and you can get

> different cables for the various mounts that support ST-4 signals.

> -Tim.

> --- In Astro_IIDC@yahoogroups.com, "-" <agrafoi@...> wrote:

>> Wonderful!

>> I have a Mac and I'm trying the try version of Astro_IIDC before to

>> buy it. When arrive the two FireFly I've purchase i'll try to use

>> one of them for autoguiding my mount.

>> By the way, I should connect the camera to the computer and the

>> computer to the mount, shouldn't I? There's not any direct way to

>> connect the camera to te ST4 port, isn't it?

>> --- In Astro_IIDC@yahoogroups.com, Milton Aupperle <milton@> wrote:

>>>

>>> Dear Agrafoi;

>>>

>>> On 21-Jul-12, at 6:47 AM, - wrote:

>>>

>>>> Hi, everybody!

>>>> I presume you don't use FlyCapture to manage this camera, but

>>>> Astro_IIDC.

>>>

>>> Yes. FlyCapture does not run under OS X.

>>>

>>>> I ask: it works all right or you need some extra software?

>>>

>>> Yes, their USB 2 camera support the IIDC protocol so they work

>>> fine -

>>> all you need is a Astro IIDC on the Mac.

>>>

>>>>

>>>> Ciao

>>>> Agrafoi

>>>>

>>>

>>> HTH...

>>>

>>> FlyCapture

>>>

> ------------------------------------

> Yahoo! Groups Links

Milton J. Aupperle

President

ASC - Aupperle Services and Contracting

Mac Software (Drivers, Components and Application) Specialist

#1106 - 428 Chaparral Ravine View SE.

Calgary Alberta T2X 0N2

1-(403)-453-1624

milton@outcastsoft.com

www.outcastsoft.com