EQ6-R Pro: Direct USB Connection How-To

In the not-so-distant past, the folks at SkyWatcher added a new feature to its popular EQ6 mount: a USB port on the mount head. This is essentially just a built-in USB to RJ-45 adapter, but it did eliminate the need to either buy a $30 cable or connect via the USB port on the hand controller running in “PC Control” mode.

The problem is… it doesn’t work. Or, at least, it didn’t for me in KStars/EKOS on either my Mac or Raspberry Pi. I combed every corner of the INDI boards looking for answers, and none of the suggestions seemed to work despite those suggestions having worked for other folks. It just would not recognize the USB port.

Finally, I found the right answer. A clever GitHub user discovered that the newest EQ6-R mounts have updated USB/serial chipsets from Prolific that are incompatible with the current stable Linux kernel releases, including those in both the StellarMateOS and Astroberry distributions. A quick run of dmesg confirms:

[   47.052706] usb 1-1.3: new full-speed USB device number 4 using xhci_hcd
[   47.209669] usb 1-1.3: New USB device found, idVendor=067b, idProduct=23d3, bcdDevice= 4.05
[   47.209680] usb 1-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[   47.209688] usb 1-1.3: Product: USB-Serial Controller
[   47.209695] usb 1-1.3: Manufacturer: Prolific Technology Inc.
[   47.209702] usb 1-1.3: SerialNumber: xxxx
[   47.216323] pl2303 1-1.3:1.0: pl2303 converter detected
[   47.218982] usb 1-1.3: pl2303 converter now attached to ttyUSB1

If “idProduct” on line 2 reads “23d3” instead of “2303,” it’s the new chipset and it will not work in the stable releases. Would not have caught that one on my own.

The fix is simple, but a bit risky: update your kernel to the latest development release. Don’t do this lightly. If you have a super-customized setup, you should be aware that upgrading your kernel can break things. At the very least, you should have a full backup that you can restore from if things go south. In the case of the Raspberry Pi, I popped the Pi’s SD card into my Mac, opened up Terminal, and used the dd command to create an image of my install that could easily be re-etched onto the SD card in the case of catastrophe.

sudo dd bs=4M if=/dev/sdb of=PiOS.img

Once you’ve got your backup, upgrading is simple. Just pop the SD card back into the Pi, re-boot, and run the rpi-update command as root. Then cross your fingers and hope things work. It did for my Astroberry setup, allowing the INDI EQMOD driver to communicate perfectly with my EQ6-R Pro mount.