detectRTSCTS relies on a timeout to discriminate if the hardware handshake is present or not. At present, it is set to 300 ms. It worked well for my setup with Celestron CPC. Probably, for other mount types, it needs a different trimming. I suggest to extend it to 500ms and to test if the problem disappears.
My naïve reading of the Connectivity section of the driver docs was that the "proper level converter" that was needed was simply something to bring 12v down to 5v, and that this was inherent to any standard USB/Serial adapter. But there's something else needed?
Perhaps the driver documentation needs some clarification and cleanup? The document I'm talking about is here: indilib.org/telescopes/celestron/celestron-aux-driver.html. One of the options it describes is "serial cable connected to Celestron AUX port." The warning about needing a "proper level converter" seems to only be with respect to the "old standard RS-232 [with] symmetric +/-12V signalling." On the other hand, the document indicates that since the "cheapest USB/serial converters . . . have serial lines with TTL levels (+5V,0V) . . . they [actually] work with AUX port."
As for the HC port, any suggestions on the best place to get a USB/Serial cable that will actually work with it?
Gene and Fabrizio's responses came while I was writing mine. Thanks guys. I did increase the timeout, by the way, to no avail. I like Gene's option. If this were my main mount (or if someone had already written up an easy recipe for doing this directly from a Raspberry Pi), I'd probably go for it. Seems like using the HC port is the better fit for me, assuming I can find the right adapter and get it to work.
In my experience is hard to distinguish between different types of USB/Serial converters from product description. 99% of low cost converters claims RS232 compatibility but they have a TTL interface (0,+5v) that works only with the so-called "TTL tolerant RS232". In our case, they can be only used for the AUX interface. For all the other mount interfaces a "quasi-true" USB/RS232 converter (-5,+5v swing ) is sufficient.
Below there is a copy taken from indilib.org/telescopes/celestron/celestron-aux-driver.html of the specification of each interface of Celestron scopes, including the required voltage swing.
<strong>HC:</strong> serial cable connected to hand controller serial port (less recent models).
4 pins connector (RJ11).
3 wires used: GND, TX, RX.
RS-232 serial voltage levels (+5V,-5V).
9600 baud transmission speed.
No transmission flow handshake, no echo.
Command protocol: pass through (mostly
AUX
protocol encapsulated inside HC messages).
<strong>HC</strong>: USB cable connected to hand controller USB port (most recent models) (alpha testing).
mini USB connector.
Command protocol: pass through (mostly
AUX
protocol encapsulated inside HC messages).
<strong>AUX:</strong> serial cable connected to Celestron AUX port.
Hi all,
I have a Celestron Evolution with a wedge.
How can I change the initial mount position for the wedge configuration?
with a wedge the mount must pointing to south, but in KStars the position is set to north. I cant set the current position. or do I need special settings for a wedge alt-az setup?
i would be create if you can give me some advice for this setup costellation.
I have been following this thread for some time. I currently connect to my AVX via that hand controller but going forward I would like to connect my Raspberry Pi directly to my mount via the AUX port and to start using this driver.
However I am struggling to undestand how to do this. Is there a pre-built USB -- RJ12 cable that can be purchased from somewhere?
Or can I use a USB FTDI TTL 5V cable and connecting the correct pins to the RJ12 plug and make it work?
I'd like to do the second option but as far as I can tell from reading numerous sources on the web, this cannot be done.
Celestron's AUX terminal (same as the hand controller connection terminal) cannot be connected with UART serial like SkyWatcher's mount.
The TTL level of the signal line is 3.3V, but it is necessary to switch the signal line electrically instead of a simple TX or RX connection.
I was able to assemble and operate the circuit on this site.
However, the Celestron Aux driver only has the coordinates of the altazimuth mount and the fork equatorial mount, so German equatorial mounts like the Advanced-VX will move to different positions. .. ..
If you use SkyPotal, you can control it directly without a hand controller.
I have compiled the information you need to create your own interface.
Please check with Google Translate etc.
If you use this circuit, you can connect the Celestron mount directly to the USB of the PC from the AUX terminal or HC terminal like EQMOD.(However, the German Equatorial Mount works because the driver does not have the correct coordinates, but it moves to a considerably different position with GOTO.)