Thanks to Alan Galitz for submitting this detailed HOWTO.

Brief Procedure

1. Update firmware 150i Mount to 3.59.45 from 3.58 (download from Skywatcher Global site) - best done with USB printer cable
2. Use SynScan App (latest version from global site), rather than Hand Controller to AutoHome Wave 150I mount
3. Power OFF Mount
4. Connect StellarMate and equipment
5. Ideally connect StellarMate controller to Mount via mount USB (Mount internal USB path works well for this)
6. Power up StellarMate
7. Check/enter TIME, LOCATION, EPOCH (JNow likely best)
8. Verify OTA/mount pointing at Home position set by AutoHome from SynScan APP (RA=0h Dec=90)
9. Pier Side (Northern Hemisphere) = west pointing east (initial default)
10. Proceed to alignment

More Details

Firmware Update

• Update firmware 150i Mount to 3.59.45 (17 Sep 2024) from https://www.skywatcher.com/download/software/motor-control-firmware/
• Firmware: MC030 Motor Controller, Version 3.59.45 - Download ZIP
• Best done via USB cable from Windows PC using Motor Controller Firmware Loader, Version 1.87
• While a wifi updater is available, users have reported incomplete updates. On an Asus NUC, the USB-A to USB-B (printer cable) update completed in ~20 seconds, though others reported longer times. Watch the Mount power light and be patient.
• Mac users can try the Mac version (v1.84) via the Wave 150i built-in USB port (not personally tested)

StellarMate Initialization Procedure

1. Power On Wave 150i and let it establish wifi
2. AutoHome the mount using SynScan App rather than Hand Controller
3. Verify AutoHome is correct: RA 0, Dec +90
4. Optional: Clear previous alignment data using SynScan App menu
5. POWER OFF mount, leaving it in Home Position
6. Connect and Power On StellarMate (see Power On Sequence below)

Source: Cloudy Nights Forum Discussion

Suggested StellarMate Power On Sequence

1. 12V Source → ON (feeds to power boxes: PPBADV2 etc)
   Wait 5–8 seconds (LED solid)
2. Mount (Wave 150i) → ON
   Wait ~10 seconds (electronics ready, USB stable)
3. USB-only Accessories → ON (cameras, focuser, dew heaters via PPBADV2)
   Do this before 12V & MeLE/PC/etc boots
4. Dual-power cameras (USB + 12V):
   • Connect USB first (PC sees device)
   • Then connect 12V (cooler/heater gets clean power)
   • Wait ~5 seconds
5. MeLE PC/StellarMate X/AsiAir etc → ON
   Wait 30–60 seconds (Linux boot complete, devices enumerated)

For mounts to report their coordinates correctly and in sky with where they are really pointing the sky requires the following conditions to be met:

1. Accurate time and time zone: This is usually automatically set by the StellarMate App. If not using the App, ensure the time is correct.
2. Accurate location: This is usually automatically set by the StellarMate App. If not using the App, ensure the location is correct. Please note INDI uses 0 to +360 for longitude. For example, if your longitude is -85 degrees, this would be (-85+360 = 275 degrees) in INDI. Therefore, do not manually change the longitude as it is usually correct.
3. Starting Position: Mount is powered up in its manufacturer's recommended home or park position.

Depending on whethet the mount is Alt-Az or Equatorial, the starting home position can be different, but in general:

• Alt-Az: Telescope level with horizon pointing North (Azimuth zero, North Hemisphere) or South (Azimuth 180, Southern Hemisphere).
• Equatorial: Counter-weights down with telescope pointing directly at the celestial pole.

Some mounts require preliminary alignment and settings via the hand-controller first before they can report any valid positions back to StellarMate. Refer to your mount manual for more details.

After initial connection, slew to mount to a nearby star at least 20-30 degrees away from the celestial pole then plate-solve with StellarMate to synchronize the moutn.

Never Synchronize the mount manually near the celestial poles as this would invalidate the mount's internal pointing.

While many telescope mounts have a default home position, some, like iOptron models, allow users to set a custom home position. It's important to remember that home and parking positions are distinct concepts, even though they might seem similar. They serve different purposes in mount operation.

Home Position:

• Reference point: This is usually a position in the sky, such as the north celestial pole or a specific star, that is used as a reference for aligning the telescope and tracking celestial objects.
• Alignment: It helps to ensure that the telescope is accurately pointed at celestial objects, allowing for precise observations.
• Tracking: Once aligned, the telescope can track celestial objects as they move across the sky, compensating for Earth's rotation.

Parking Position:

• Storage: This is a position where the telescope can be safely stored when not in use.
• Protection: It helps to protect the telescope from weather, dust, and other elements.
• Convenience: It often makes it easier to set up the telescope for future observations.

From StellarMate App, use the Mount Quick Controls (1) to see if you mount support Homing functions (2). If it is supported, slew your mount using the directional control to your intended target and then tap the Home icon and tap Set. This should save the current position as the Home position for your mount.

Please watch the tutorial given below: