Karl Rees replied to the topic 'indi_celestron_aux' in the forum. 7 months ago

My other mount is in the shop, so I thought I'd play around with this driver and my old Nexstar SLT to put together a first smart-scope for my kids.  But it's not quite working out.  Has anyone tried this driver with an older (circa 2008) Nexstar SLT?  

It appears to be working directly through the handset, but the whole point of this driver to me at least is to connect directly to either the HS or AUX port.  For the HS port, I'm wondering if my USB-Serial (FTDI) adapter lacks symmetric voltage.  I'm trying to find a compatible adapter, but the ones on Amazon tend not to specify whether they support symmetric voltage.

For the AUX port, I've successfully used the SkyPortal WiFi module (which I lost) with this mount in the past, so my understanding is that I should be able to use the AUX port.  I've made my own cable, so maybe I did something wrong there.  Here's what I did:

RJ12 pin 1 <-> DB9 pin 8 (CTS)
RJ12 pin 2 <-> DB9 pin 2 (RX)
RJ12 pin 3 (not connected)
RJ12 pin 4 <-> DB9 pin 3 (TX)
RJ12 pin 5 <-> DB9 pin 5 (GND)
RJ12 pin 6 <-> DB9 pin 7 (RTS)

The driver thinks it is connected, but the mount does not respond to commands.  Looking at the logs, the driver does not appear to actually be receiving anything from the mount,  Rather it's just getting back an echo of what it sent, which it then ignores.

Looking deeper into the logs and the code, it appears to not be receiving a CTS signal.  detectRTSCTS() returns false.  There are no handshake errors, which I interpret to mean that waitCTS() is never seeing the TIOCM_CTS flag.  I'll spit out an excerpt from the log below just in case I'm misinterpreting.

DEBUG    6.428512 sec    : Connecting to /dev/serial/by-id/usb-FTDI_FT232R_USB_UART_A16IRNH1-if00-port0 @ 19200
DEBUG    6.436192 sec    : Port FD 3
DEBUG    6.436338 sec    : Connection successful, attempting handshake...
DEBUG    6.436417 sec    : CAUX: connect 3 (serial)
DEBUG    6.792473 sec    : detectRTSCTS = false.
INFO    7.349836 sec    : Setting serial speed to 9600 baud.
CSER    7.400070 sec    : CMD <56>
CSER    7.400170 sec    : aux_tty_read: 3
ERROR    8.401306 sec    : Timeout error
INFO    8.401479 sec    : Detected Mount USB serial connection.
DEBUG    8.401557 sec    : Communicating with mount motor controllers...
CAUX    8.401638 sec    : CMD <     GET_VER>  APP ->  AZM
CSER    8.451916 sec    : CMD <3B 03 20 10 FE CF>
CSER    8.452100 sec    : aux_tty_read: 3
CSER    8.452221 sec    : aux_tty_read: 3
CSER    8.452312 sec    : aux_tty_read: 3
CSER    8.452436 sec    : RES <3B 03 20 10 FE CF>
CSER    8.452583 sec    : Got 4 bytes:  ; payload length field: 3 ; MSG:
CSER    8.452688 sec    : [3B 03 20 10 FE CF]
CAUX    8.452758 sec    : RES <     GET_VER>  APP ->  AZM
CAUX    8.452825 sec    : Got msg not for me (AZM). Ignoring.
CAUX    8.452903 sec    : CMD <     GET_VER>  APP ->  ALT
CSER    8.503168 sec    : CMD <3B 03 20 11 FE CE>
CSER    8.503328 sec    : aux_tty_read: 3
CSER    8.503422 sec    : aux_tty_read: 3
CSER    8.503501 sec    : aux_tty_read: 3
CSER    8.503595 sec    : RES <3B 03 20 11 FE CE>
CSER    8.503673 sec    : Got 4 bytes:  ; payload length field: 3 ; MSG:
CSER    8.503737 sec    : [3B 03 20 11 FE CE]
CAUX    8.503795 sec    : RES <     GET_VER>  APP ->  ALT
CAUX    8.503852 sec    : Got msg not for me (ALT). Ignoring.
INFO    8.503909 sec    : Got response from target ALT or AZM.
DEBUG    8.503965 sec    : Connection ready. Starting Processing.
INFO    8.504064 sec    : Celestron AUX is online.

The rest of the log goes on in much the same pattern: a new CMD is issued, it's echoed back in the RES, and is ignored.

Further information: the driver is showing version .10 and was self-compiled yesterday from the main branch.  The motor controller firmware is 5.18.  

This is not a super high priority for me, but I'm OCD when it comes to these things.  I'd hate to think I was just a small step away from solving it.  Thanks in advance for the help.  

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