Update FAQ to include EQ, system clock and mount control

docs/source/user_guide.rst

@@ -674,4 +674,53 @@ Instructions for writing software release images to an SD card can be found on t
 FAQ
 ====
 
-Have any questions?  Please send them through to me at `info@PiFinder.io <mailto:info@pifinder.io>`_ and I'll do my best to help and potentially add your question here.  Better yet, feel free to fork this repo and contribute via a pull request!
+Have any other questions?  Please send them through to me at `info@PiFinder.io <mailto:info@pifinder.io>`_ and I'll do my best to help and potentially add your question here.  Better yet, feel free to fork this repo and contribute via a pull request!
+
+The operating system clock of PiFinder is off?!?
+--------------------------------------------------
+
+PiFinder is designed to run standalone, with-out internet. The Raspberry Pi does not have a real-time clock, so it cannot keep track of time accurately without an internet connection. 
+It stores the current time in a file when it shuts down and reads that time when it starts up to get an estimate of the current time, but this will be off by several days or more if the PiFinder has been off for a while.
+Therefore we cannot rely on the system clock being correct. The PiFinder software only trusts the GPS time and does not use system time. There's one exception and that is for timestamps 
+in log files. 
+
+If you want to synchronize the system clock to the GPS time, you can run the following commands from a terminal on the PiFinder:
+
+.. code-block:: bash
+
+   sudo apt update
+   sudo apt install chrony
+
+Then in /etc/chrony/chrony.conf add 
+
+.. code-block:: text
+
+   refclock SHM 0 poll 3 refid gps1
+
+before the „pool“ directive. 
+
+This enables chrony to use the GPS time as a reference and will keep the system clock synchronized with GPS time.
+If you're using PiFinder, when connected to the WiFi (in client mode), chrony will very probably prefer internet NTP servers over the GPS time, so 
+OS time may still be a couple of seconds off. 
+
+Note that when running off grid, and until you get a GPS lock, the system clock will still be off and timestamps in the log may still be inaccurate. 
+
+Can I use the PiFinder on an EQ mount?
+----------------------------------------
+
+The PiFinder works with any mount, including EQ mounts.  The plate solving will work the same regardless of mount type. You can switch PiFinder to EQ mode by navigating 
+to :ref:`user_guide:settings menu` and changing the "Mount Type" to EQ.  This will change the Push-To instructions to be in RA/Dec instead of Alt/Az (indicating +/- in both axes).  
+
+In prior versions of the software (2.5.0 and less) the accelerometer-based tracking will not work correctly in EQ mode.  This means that the Push-To instructions will be strange when 
+you move the scope, but when you stop moving and the camera can plate solve, the real distances to the target will be shown.
+
+From version 2.6.0 on, EQ mode will be fully supported with accelerometer tracking.
+
+Can I control my motorized mount with the PiFinder?
+-----------------------------------------------------
+
+Not yet. Development of this functionality is ongoing. Note that this feature will depend on INDI support for your mount, so even when we have the software ready, it may not work with all mounts. 
+Please check INDI's list of supported mounts to see if yours is supported: http://drivers.indilib.org/mounts/
+
+Most likely this will be based on another improvement, that we are working on, which updates the operating system to a different distribution, 
+which will allow us to use a more recent version of INDI that has better support for current mounts. Therefore we do not have an arrival date for this feature yet.