Controlling a GoTo telescope from your mobile phone has become almost as commonplace as opening a weather app. These days, it's perfectly possible to move the mount, perform alignments, plan your session, and even trigger the camera without leaving your chair, provided you understand which module you need, which software to use, and how they all communicate with each other. In this article, we'll calmly break down all the real options for... control GoTo mount telescopes from mobile apps, both via WiFi and Bluetooth or through intermediate servers such as INDI or ASCOM.
Throughout the text you will see specific cases with SkyWatcher, Celestron, Avalon equipment and open systems based on INDI, as well as examples of apps such as SynScan Pro, SkySafari, Telescope.Touch or StarGO-BTWe'll also discuss details that are often overlooked: module power supplies, LiPo batteries, polarity risks, PC Direct modes, and how to integrate everything with astrophotography programs like NINA, PHD2, or Cartes du Ciel without the setup becoming a nightmare.
Why does it make sense to control the telescope from your mobile phone?
Nowadays, those who haven't tried controlling the bike from their mobile phone tend to underestimate how convenient it is to be able to move the telescope with an app while you're indoors or sitting far from the tripod. Beyond simple convenience, there are two very powerful underlying ideas: the concept of IoT (Internet of Things) and the use of the cloud as a natural work environment.
When you connect the mount to your home network, either via WiFi or Bluetooth to a mini PC, you enter an ecosystem where it's normal mix local and remote controlYou can perform plate solving for alignment, adjust guiding from a laptop in another room, or receive notifications on your mobile phone when an astrophotography sequence ends and, if needed, Control your Android device from your PCJust as today no one is surprised to open the garage door with a smartphone or start the coffee maker from work, in astronomy it is becoming increasingly common operate the mount without touching a single physical button..
SynScan WiFi module for SkyWatcher GoTo mounts
One of the most appreciated accessories for SkyWatcher users is the SynScan WiFi moduleThis small device connects to the GoTo mount and effectively turns it into a fully controllable device, accessible from a mobile phone, tablet, or computer, without relying on the physical remote.
This module is compatible with virtually all all SkyWatcher GoTo mountsBoth altazimuth and equatorial mounts are supported. Some recent models, such as the Mak 127 AZ-GTi or certain modern Dobsonian GoTo mounts, already have built-in Wi-Fi connectivity. For the rest, an external module is the easiest way to obtain the same functionality without changing the mount or electronics.
How to connect the SynScan WiFi module
The SynScan WiFi module works much like a home router: the device itself creates a wireless network, and your device connects to it. After plugging it into the appropriate port on the mount, you'll see a network appear with a name like [insert name here]. SynScan followed by numbersYou just need to go to the network menu on your mobile phone or tablet and connect as you would with your home WiFi.
It is important to remember that this network It does not require internet accessThe module creates its own closed local network, so when you join it, your device will disconnect from your regular router and you'll lose internet access through that connection. This isn't a problem for controlling the telescope, but it's something to keep in mind if you also want to use other apps that require an external connection.
Once the WiFi connection is established, all that's left is to open the app. SynScan Pro and tap "Connect". The app will detect whether the mount is altazimuth or equatorial and adjust the control mode accordingly. From there, you can manage the entire system from your mobile device, with access to alignment, object selection, manual movements and selection of tracking and scrolling speeds.
Apps compatible with SynScan WiFi and where to find them
SkyWatcher offers the app SynScan Pro for different platforms. On iOS devices, you'll find it in the Apple App Store. On Android and Windows, you can download it directly from the manufacturer's website, in the SynScan software section.
In addition to serving as a virtual controller, SynScan Pro is the component that makes bridge between the mount and other programsOn Windows, the application can run in the background while an ASCOM driver provides a standard interface to planetarium or astrophotography software. This allows almost any ASCOM-compatible software to communicate with your SkyWatcher mount via the Wi-Fi module.
ASCOM integration: taking the mount to the next level
For those who do astrophotography or need more advanced control, the real leap comes when you connect the mount to external programs using ASCOMThis standard allows hundreds of applications to communicate with cameras, mounts, focusers, and other accessories without relying on different proprietary drivers for each model.
The typical workflow with a SynScan WiFi module in Windows is usually: first install the ASCOM platform From its official website, then add the specific "SynScan App Driver" from SkyWatcher, and finally ensure that the SynScan Pro app for Windows is open while using other programs. In this setup, the ASCOM driver acts as a translator between programs like NINA, Cartes du Ciel, APT, Sharpcap, or PHD2 Guiding and the SynScan Pro application, which is the one that communicates directly with the WiFi module.
The advantage is obvious: you can plan complete astrophotography sessions, do plate solving, synchronize coordinates, automate meridian flips and autoguide without running a single additional cable from the computer to the mount, which greatly simplifies field setup and reduces the risk of snagging in the middle of the night.
Practical advantages for beginners and advanced users
For beginners, using an app instead of the standard remote offers a huge improvement in ergonomics: the touch interface is clearer, the text is legible, and navigating the menus is much more intuitive than with the original remote. small screens of classic controllerswhere it is often difficult to read well in the dark.
For the advanced hobbyist, the interesting thing is that these types of modules even allow autoguiding with PHD2 and work with planning software like NINA or Cartes du Ciel without physically connecting anything to the mount's port beyond the WiFi module itself. This allows for a very clean astrophotography setup, with only the essential cables for cameras and power, and all pointing and tracking control managed via the network.
Advanced GoTo control: Avalon StarGo with WiFi and Bluetooth
In the mid-to-high-end segment, one of the most complete systems is the Avalon's StarGo GoToThis is a controller based on stepper motors, designed for mounts of the brand itself (M-Zero, M-Uno, Linear) but also adaptable to models from other manufacturers through motor kits and configuration of gear ratios.
The StarGo main unit acts as the brain of the system: it manages the right ascension and declination engines, and provides a smart interface with multiple ports It communicates with accessories (focusers, filter wheels, DSLR cameras, auxiliary motors) as well as computers and mobile devices. The design aims for simple yet highly flexible hardware, enabling it to support new devices via software without requiring constant physical upgrades.
Wireless connectivity and control via StarGo apps
The StarGo control unit integrates ports as standard USB, WiFi and BluetoothIn addition to classic connections such as the ST4 port for autoguiding, it allows interaction with the system from Windows and Mac computers, as well as smartphones and tablets.
In addition to the classic StarGo physical keyboard (which functions as a handheld controller for routine operations), Avalon offers several software applications: the StarGo desktop program, focused on detailed device management, and the app StarGo-BT for AndroidThis feature transforms your mobile phone into a wireless control panel. With it, you can move the mount, select objects, and access some functions without a USB cable.
Sky modeling and alignment functions using plate solving
One of StarGo's strong points is its tool X-SolverBased on the plate solving technique, this utility allows you to build sky models of up to 24 stars, store those models, and reuse them in subsequent sessions—something especially useful in fixed observatories where the mount does not move between nights.
Using two auxiliary tools, Sky Model and Polar Align, the system facilitates both the generation of the model and the assisted polar alignmentSky Model displays a 2D map of the sky on which the user can select stars with a simple double-click, while Polar Align guides the mount adjustment process based on plate solving. Although primarily designed for fixed installations, the speed of the process allows it to be used with portable equipment as well, especially when combined with a short camera-based phase at the beginning of the session.
Technical specifications and compatibility with external software
On a technical level, StarGo offers a wide variety of movement and tracking speedsThe system allows you to define the gear ratio (for example, values ​​like 1234,123) and save configuration files. It features guiding modes with factors from 0,05 to 0,95x, centering speeds from 2 to 10x, searches from 10 to 150x, and maximum slew speeds that can reach around 1400x at 12/18 V, depending on the mount's reduction ratio.
As for tracking, it includes sidereal, solar, lunar, and terrestrial rhythms, with a fine-tuning function. An internal database with approximately 14.000 Objects The defaults serve as a starting point, and the user can easily edit it using a simple text editor, leaving the way free to add custom catalogs.
ASCOM connectivity is resolved through the AvalonStargo driverwhich allows interaction with most common programs: PHD2, TheSkyX, Starry Night, MaximDL, Sequence Generator Pro, Cartes du Ciel, Stellarium, and others. In this way, the StarGo system integrates seamlessly into established astrophotography workflows.
Bluetooth control with HC-05/HC-06 modules and SynScan remote control
Beyond the official modules, many enthusiasts opt for homemade solutions based on Bluetooth modules type HC-05 or HC-06These small, very inexpensive devices can act as a wireless link between the mount and a tablet or mobile phone, usually through applications such as SkySafari or specific clients.
In some setups, the Bluetooth module connects directly to the mount, drawing power from it and reducing the voltage to 5V via a small regulator. However, several users have found that connecting the module to the SynScan remote It offers advantages: the data signal is at 5V TTL instead of 3,3V and, in addition, the remote control is always kept at hand to make manual corrections or quick changes in alignment without depending solely on the mobile device.
Power issues: LiPo batteries and safety
When using an external Bluetooth module independent of the mount, it is often necessary to small LiPo batteriesThese are very common in aeromodelling. They are similar to the Li-Ion batteries in mobile phones, but with greater capacity and discharge rate, making them ideal for powering a wireless module overnight with hardly any added weight.
These batteries require certain precautions: they should not be discharged below approximately 3V or charged above 4,2V per cell. Ideally, a LiPo charger specifically designed for LiPo batterieslike those used in model aircraft. In many cases, the Bluetooth module cannot be charged simply by connecting its mini USB port to the computer, so it's best not to assume it will charge the LiPo battery; it's safest to charge the battery separately.
When connecting the battery to the module, some users fabricate adapters with male mini JST connectors, repurposed from model airplane projects. LiPo batteries with the exact same connector as the Bluetooth module have also been found, so that There's no need to solder or file pinsEven so, it's vital to always check the polarity: depending on the device the battery is designed for, the positive and negative wires may be reversed. Incorrect polarity can burn out the module upon first connection.
Using PC Direct mode and combined control
When working with controllers like the SynScan, there is a special mode called PC DirectThis mode allows the controller to act as a simple interface between the mount and a computer or external adapter, without filtering or interpreting commands. This mode is used, for example, to update motor firmware, and some users force it to activate only in such cases.
When connecting a Bluetooth or WiFi module to the controller instead of the mount, it's important to know whether PC Direct is automatically activated in certain configurations or if it needs to be forced, as this affects the functionality of external applications. can send GoTo commands directlyAlthough each combination of firmware and controller may vary, it is an option to keep in mind and should be checked in the controller's own settings menu.
Compatibility with Celestron mounts and RS-232/USB cables
In the case of Celestron, many NexStar controllers, even from previous generations, have a "phone" type port that allows connection to a computer via a RS-232 adapter cableSome users also already have the USB adapter, so the controller can be connected to a laptop without too much trouble.
To add wireless control to such a system, you can use the same ports and cables by connecting a specific adapter that provides Wi-Fi or Bluetooth from the serial signal, without needing to splice or solder if the device comes with the appropriate connectors. In any case, it's advisable to do so before buying a generic adapter. Check the exact model of your NexStar remote. and the pin arrangement of its connector, because not all controllers or all generations work the same.
Control via INDI and the Telescope.Touch app
Beyond the ASCOM world and proprietary solutions, there is a very powerful open-source software ecosystem surrounding the INDI library (indilib.org), designed to control astronomical equipment under Linux, macOS, and other systems. The mobile application fits into this environment. Telescope.Touch, a planetarium with mount and focuser control that is inspired by Google Sky Map, but adds GoTo pointing, CCD image reception and INDI device management features.
Telescope.Touch is a project open sourceAvailable on GitHub, its philosophy is clear: the app doesn't connect directly to the mount, but to an INDI server running on a computer on the local network. In other words, the mobile device becomes a client that sends commands to the server, which in turn controls the mount, focuser, camera, and other accessories supported by INDI.
Requirements and basic configuration with INDI
To use Telescope.Touch, the first requirement is to have a active INDI server on the computer that controls the device. That PC must be on the same network as the mobile device, either through the home router or a portable Wi-Fi access point. The app allows you to define the server address and port (7624 by default), add multiple different servers to the list, and use automatic discovery of network services compatible with Avahi/Bonjour.
Once connected to INDI, the application offers a general control panel Accessible via the gear icon. There, all the properties of the detected devices (mount, focuser, camera, etc.) are displayed, organized by tabs. Tapping on each property allows you to edit values ​​or view details, depending on what each INDI driver supports.
GoTo movements, focus, and image capture
The Telescope.Touch display provides access to the movement module, with directional controls and speed adjustments. The buttons are enabled or disabled depending on the mount's capabilities and whether the device is properly connected to the INDI server; if there is a communication failure, the buttons remain inactive.
The app includes a database with some 1300 Objects (planets, bright stars, and common NGC objects) that can be targeted directly from the mobile device using GoTo, plus a button to lock or unlock tracking. In parallel, the focuser section allows you to move the focus in or out, set absolute positions, and adjust the movement speed if the driver supports it.
Regarding cameras, Telescope.Touch is capable of receiving CCD images in FITS format (monochrome only) and JPG, giving the option to stretch the FITS image. better visualize faint objects and low-magnitude starsIt also allows you to save both these images and the Aladin Sky Atlas previews associated with the sky objects to your device.
Mobile planetarium, augmented reality, and other useful apps
In this era of mobility, mount control goes hand in hand with a whole collection of mobile astronomy apps. Planetariums like Skysafari Night Sky turns your smartphone into an interactive star chart with which you can point to areas of the sky, tap on an object and send a GoTo command to the telescope, provided there is a communication channel (WiFi, Bluetooth, INDI, remote ASCOM) correctly configured.
There are augmented reality-based apps, such as Universe2go, that combine the real sky field with superimposed information, and specific tools such as PolarScope Alignfocused on facilitating polar alignment of the mount. We also find apps dedicated to specific celestial bodies, such as MoonGlobe for the Moon or JupiterMoons and SaturnMoons for tracking satellites and planetary details; there are also guides for Take photos of the Moon with your mobile phone.
To plan the night, weather apps dedicated to astronomy, such as ClearOutside or Sky Live, offer Detailed forecasts of clouds, seeing, transparency and darknesshelping to decide whether it's worth setting up all the equipment or if it's better to leave it for another night.
What to consider before diving into wireless controllers
Before you start controlling your GoTo mount with your mobile phone, it's worth reviewing several key points: checking the exact compatibility of your mount and controller With commercial WiFi or Bluetooth modules, check the voltages and polarities if you are going to power external modules with LiPo batteries, and decide whether you are going to base your workflow on ASCOM, INDI or closed proprietary solutions.
It's also important to consider the usage scenario: it's not the same to want to move the mount for relaxed visual observation, where perhaps a simple Bluetooth module and an app like SkySafari will suffice, as it is to set up a semi-automated observatory with plate solving, sky models, wireless autoguiding, and remote control from inside the houseDepending on that ambition, accessories such as SynScan WiFi, StarGo, or an INDI server with Telescope.Touch on the local network will be a better fit.
One way or another, the leap to controlling your GoTo telescope from your mobile phone opens the door to more comfortable sessions, cleaner setups, and much greater integration with the rest of the digital tools you already use daily, from weather forecasts to image processing, all with the feeling that the mount is just another device within your own connected ecosystem. Share the guide and more people will know how to use their GoTo telescope with their mobile phone.
