7  Mounts and WiFi Accessories

Polaris already drives the vast majority of WiFi-capable telescope mounts on the market through INDI, the open-source driver system astronomy gear speaks on Linux (Chapter 5): indiserver, the small background program that hosts INDI drivers, runs on the host (a Raspberry Pi or mini-PC) and the INDI mount driver speaks WiFi on Polaris’s behalf. This chapter maps which mounts work that way today, walks through a typical setup, and covers the direct drivers that let Polaris talk to a mount with no indiserver at all.

7.1 WiFi mounts through INDI

Pick INDI as the driver in the RIGS tab’s Mount card, then connect. No extra Polaris setup is required beyond installing the INDI driver package on the host.

Brand Bodies INDI driver
Sky-Watcher AZ-GTi, AZ-EQ5, EQ5-Pro, HEQ5 Pro, EQ6-R Pro, EQ8-R Pro, AZ-EQ6, GoTo Dobsonians, AllView indi_skywatcherAltAzMount / indi_eqmod_telescope
Celestron CGX, CGX-L, CGEM II, AVX, NexStar SE/Evolution, CPC, StarSense Explorer indi_celestron_aux / indi_celestron_gps
iOptron CEM26, CEM40 (+EC), CEM70 (+EC), CEM120, HEM27, HEM44, HEM47, GEM28, GEM45, SkyTracker, SkyGuider Pro indi_ioptron_v3
Meade LX200 / LX200GPS, LX600, LX850 (with Stella WiFi adapter) indi_lx200gps / indi_lx200_OnStep
Astro-Physics 1100 GTO, 1600 GTO, Mach1, Mach2 indi_lx200_OnStep (Keypad) / indi_apgto
10Micron GM-1000, GM-2000, GM-3000, GM-4000, AZ-2000 indi_lx200_10micron
Vixen SXP, SXP2, AXJ, SXD2 indi_lx200_classic
Losmandy G-11, G-11G, GM-8, GM-811G indi_lx200gps
ZWO AM3, AM5, AM5N indi_skywatcherAltAzMount (compatible protocol)
StarAid Revolution standalone autoguider, pairs with the mount via the standalone STA-1 cable indi_celestron_aux
Generic Anything that speaks LX200 / NexStar / SynScan over TCP/IP indi_lx200generic

On Windows, Polaris also accepts ASCOM Alpaca mounts (ASCOM is the long-standing Windows standard for astronomy drivers; Alpaca is its network flavour): the manufacturer’s official driver (Celestron PWI, SkyWatcher SynScan, iOptron Commander) typically exposes ASCOM, which Alpaca converts to ordinary web traffic that Polaris consumes (The ASCOM Initiative, n.d.). On Windows the direct ASCOM door (COM, the Windows plumbing that lets one program call directly into another) works too; see Chapter 5.

7.2 Setup walkthrough: Sky-Watcher AZ-GTi

  1. On the AZ-GTi, switch the small slider on the side to WiFi AP mode (AP means access point: the mount broadcasts its own WiFi network; this is the factory default).

  2. From the Polaris host, join the SynScan_xxxx network broadcast by the mount.

  3. Install the EQMod or AltAz driver package on the host:

    sudo apt install indi-eqmod indi-skywatcherAltAzMount

  4. Start indiserver pointing at the WiFi driver:

    indiserver -v indi_skywatcherAltAzMount

    or use the embedded INDI drivers manager (Chapter 5) to start a profile that includes it.

  5. In the RIGS tab’s Mount card, pick INDI in the driver dropdown, choose SkyWatcher Alt-Az WiFi (or whatever name the driver reports), and click Connect.

The same recipe works with indi_celestron_aux for Celestron WiFi accessories (SkyPortal, StarSense Explorer) and with indi_ioptron_v3 for iOptron mounts with built-in WiFi.

7.3 Direct drivers, no indiserver

For users who would rather skip the indiserver step, or who run Polaris on a host without it, Polaris’s mount layer has slots for direct drivers that speak the mount’s own network protocol over UDP or TCP (the two basic ways programs send data across a network; TCP confirms delivery, UDP just sends and hopes). One of them has shipped; the others are tracked backlog and appear as (not installed) in the driver dropdown until their backend lands.

SynScan WiFi (UDP), Sky-Watcher: shipped

The Sky-Watcher SynScan (Wi-Fi UDP) driver is implemented and selectable in the Mount card today. It talks directly to the mount’s own UDP server on port 11880 using the SynScan App protocol, skipping the INDI and ASCOM layers entirely; this is the natural path for the typical AZ-GTi user with a phone-only setup adapting to a Polaris host.

  • Bodies: anything with a SynScan-compatible handset, the WiFi adapter, or built-in WiFi (AZ-GTi, AllView, EQ8-R Pro, EQM-35 Pro, AZ-EQ6 GT with the WiFi accessory, GoTo Dobsonians). It likely also drives the ZWO AM5N and AM7 in SynScan-compatible mode.
  • Address: the device id is a host[:port] string, defaulting to 192.168.4.1:11880, the mount’s factory access-point address.
  • Authentication: none. Anyone on the WiFi network can drive the mount.
  • Protocol shape: plain-text (ASCII) command frames over UDP, similar to the serial command language of Meade’s classic LX200 telescopes, which many other mounts adopted (:e1 reads RA/Dec, the sky coordinates right ascension and declination; :Sr / :Sd set the target, :MS slews, :Q aborts, :Mn / :Ms / :Me / :Mw jog). The reference is the SynScan WiFi protocol PDF published by Sky-Watcher on their developer site.

The driver covers slewing (with sync: telling the mount where it is really pointing so it can correct its aim), position readout, tracking on and off, park and unpark, and guide-rate control, so the sequencer, Slew & Center, and the meridian-flip machinery (the mount swinging the telescope to the pier’s other side as the target crosses the meridian) all work through it unchanged.

NexStar WiFi (TCP), Celestron: backlog

  • Protocol: the Celestron NexStar serial protocol wrapped in TCP on port 2000.
  • Bodies: any mount with the SkyPortal WiFi accessory or the StarSense Explorer WiFi dongle (CGX, CGEM II, AVX, NexStar SE, NexStar Evolution).
  • Authentication: none.
  • Protocol shape: raw NexStar serial bytes, one byte per command with fixed-length responses (e reads precise RA/Dec, s syncs, r slews to precise RA/Dec, M cancels, P moves an axis at a rate).

Pure TCP with no vendor library to load, cross-platform; the estimated effort is about a day.

LX200 TCP, Meade and friends: backlog

  • Protocol: the same plain-text LX200 command language, over TCP. The port varies: typically 4030 on the Meade Stella WiFi adapter and 4000 with most bridges for OnStep (a popular DIY telescope-controller firmware) and SkySafari (the popular planetarium app).
  • Bodies: Meade LX200, LX600, and LX850 with the Stella WiFi accessory, plus dozens of clones, OnStep builds, the Pegasus NYX-101, and iOptron iEQ-series mounts with the iOS-style hand controller.
  • Effort: about half a day once SynScan-style plumbing exists, since the command set is similar (:GR / :GD / :Sr / :Sd / :MS / :Q).

Choosing a driver

Setup Recommended driver
RPi / mini-PC with indiserver running INDI (one driver list to maintain, every mount supported)
Windows with ASCOM installed Alpaca or ASCOM (COM, direct)
Linux / Mac, no indiserver, no ASCOM, just Polaris SynScan WiFi today; NexStar WiFi / LX200 TCP when they land
Anything else INDI on the host, period

7.4 Bluetooth: out of scope

The current mount market is essentially WiFi-only. Bluetooth shipped on a handful of older bodies (the Celestron NexStar SE with the optional SkyAlign BT module, a few SynScan Hand-Controller v3 firmwares), the device pairing on the BT side never standardised, and modern bodies dropped it entirely. If a real user shows up needing BT, the path would be to pick a target body (likely a NexStar SE with the BT module), use each OS’s own Bluetooth machinery for discovery (not cross-platform out of the box), and wrap the same NexStar serial protocol over RFCOMM (Bluetooth’s emulation of a serial cable). It is not on the roadmap; WiFi covers every mount worth tracking.