I normally connect to my NEQ6 mount using EQMOD over bluetooth with Astroberry. This works OK but I have experienced the occasional random disconnection. I have decided therefore to go back to the good old reliable method of using a wired connection to the mount using USB to TTL conversion. I made up a cable using a FTDI chip a while back and it worked fine on the ASCOM based windows system I was using then. I now want to use the same cable on an INDI connected system using Astroberry. However it doesn't want to connect when I simply plug the cable in and try and connect the EQMOD mount. The default port setting is /dev/rfcomm0 and if I try to scan for other ports on the connection tab I get a message saying "no candidate ports found on the system for EQMOD connection". I notice however you get this message even if nothing is connected ! It may be therefore that the RPi is not sensing the connection at all and there is a physical problem with the cable. I seemed to remember when using the said cable with Ascom there was a FTDI driver that I needed to download.
Am I expecting too much to expect a connection simply by connecting the cable and trying to connect using the existing EQMOD Indi dirver in Astroberry ? Or is there a setting I am missing or another driver. ? The EQMOD Indi driver works ok using Bluetooth as the medium and I would have though this was more complex.
When you connect the cable the Linux system should detect it whether the mount itself actually is connected or not. You can test if this works by opening a terminal on the Astroberry and typing
dmesg -w
This will start displaying Linux kernel messages and the -w parameter means that dmesg will wait for new incoming messages. If you then insert the FTDI cable, you should see new messages appear. In my case I see
[31300.596814] usb 1-3: new full-speed USB device number 2 using xhci_hcd
[31300.755777] usb 1-3: New USB device found, idVendor=0403, idProduct=6015, bcdDevice=10.00
[31300.755796] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[31300.755809] usb 1-3: Product: USB TTL 5V
[31300.755821] usb 1-3: Manufacturer: EBCONNECTIONS
[31300.755830] usb 1-3: SerialNumber: EB1SFKV8
[31300.850817] usbcore: registered new interface driver usbserial_generic
[31300.852115] usbserial: USB Serial support registered for generic
[31300.860450] usbcore: registered new interface driver ftdi_sio
[31300.860991] usbserial: USB Serial support registered for FTDI USB Serial Device
[31300.861074] ftdi_sio 1-3:1.0: FTDI USB Serial Device converter detected
[31300.861194] usb 1-3: Detected FT-X
[31300.862498] usb 1-3: FTDI USB Serial Device converter now attached to ttyUSB0
and when I pull it out I see
[31311.104224] usb 1-3: USB disconnect, device number 2
[31311.108532] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now disconnected from ttyUSB0
[31311.108673] ftdi_sio 1-3:1.0: device disconnected
Press ctrl-c to stop the dmesg command. Note that when I connect the cable that the port (in my case ttyUSB0) is displayed. Perhaps that will help you further debug your issues?
Thanks very much Wouter.
Your response is very useful as it now enables me to troubleshoot my connection.
I fear my lead is slightly dodgy but at least I can see what is going on - or not !
It must a cable issue. No drivers are required for FTDI UART. I use one of these. When plugged a new USB device should be detected automatically, if no other serial devices are connected to USB it should be /dev/ttyUSB0
Use this device in your EQMod driver and you should be fine.
Note: /dev/rfcomm0 is BT serial device.
Thanks for your response. Yes I've experimented with the dmesg command and I can sometimes get the Pi to recognise the UART but it doesn't appear to be communicating with the mount properly .
I agree it looks like a dodgy cable and I have ordered another .
Great work on your latest Astroberry image BTW ! The RPi 4 has definitely got what it takes for a much better astrophotography experience.
Cheers
Ian