ARO-Master is an affordable and integrated control system for Automated Remote/Robotic Observatories with Roll-Off-Roof or non-rotating Clamshell Domes design.
A Remote Observatory is any observatory that can be operated without a physical presence near the equipment, whether the user is in the next room or on the other side of the planet. Of course, if the user is in the next room, he can more easily resolve any problem/emergency that arises, on the other hand if you are on the other side of the planet things are more complicated, in the development of Aro-Master we tried to take this into account.
In addition to sliding Roof movement management and Pier management, one of the essential requirements was the need to close the roof even when the power supply fails, for this purpose an integrated switching power supply (SMPS) + uninterruptible power supply (UPS) + battery management system (BMS) system was used, along with a simple 12V external battery (Gel, AGM, Acid), which allows security for remote operation.
This is a project that tries to maintain the KISS philosophy as much as possible, without the usual mess of folders and files in the Github repository as sometimes happens, especially when it comes to software/firmware.
The software was written in C/C++ (no, it does not use "arduinos" or interpreted languages byte-code or not, nor copy & paste code from others, nor a huge amount of libs made by no one knows exactly who or what type of code they contain) and it doesn't even have dependencies on other libs besides the normal Linux ones. Remote control must be taken very seriously, all code must be fully under our control and be fail proof.
The PCB board and electronic schematics were designed with Eagle 6, PCB boards can be obtained directly from me or ordered directly from one of the many board manufacturers.
Below in the licensing section you can read more information on how to obtain the firmware and the complete assembled version of ARO-Master.
Hardware & firmware that implement the server/daemon for Observatory control (remote and local).
This is the main brains that allows you to connect and control all the equipment, open/close the roof, see weather conditions, see the sky, see the observatory interior, control user login, control the Piers etc.
Relays box for each Pier that is connected to ARO-Master, allows you to turn on and off the equipment (mount, PC, power box, etc.).
Up to 6 Piers can coexist at the same observatory (this limit is a practical matter, technically it is possible to expand the system to use up to 64 Piers, but an observatory with more piers implies a larger and heavier sliding roof which will require a more powerful motor and greater power supply requirements).
When I made the decision to share this project I intended to make it public, but recent developments have changed that intention. So, for now I will share the firmware only in its compiled form (without the sources) and the hardware schematics are provided as reference material only.
There will be a commercial version that can be purchased as a kit or already assembled, in addition to the two electronic components mentioned (ARO-Master box & Pier-Relays box) there is also extra hardware that can be purchased by end users, such as the rack and pinion and motor for roof movement.
I started this project in 2015 and to date it has undergone several upgrades in terms of hardware and software. The first version was developed around an STM32-E407 microcontroller but this quickly proved to be insufficient for everything I wanted to implement, both in terms of hardware and firmware features. The current version uses a Raspberry PI 4 with at least 2GB of memory for the ARO-Master box and uses RP2040/RP2350 microcontrollers for the Pier-Relay box .
This system is in use in my personal observatories and those of some colleagues, two of which are located in Tunisia and are remotely controlled from Europe.
- No software instalation needed
- Accessible from anywhere
- OS independent using Windows, Linux, Android or Mac browser
- Auto firmware updates
- Provides a Wi-Fi hotspot
- No need for extra Wifi router for connecting you Wifi devices (IP camera, Smart Plugs, etc) to the Internet
- Direct integration with uAstro SkyPatroll (MSP) or uAstro Weather Station (MWS)
- Alpaca Discovery aware (no setup or configuration needed)
- Implements Alpaca devices Dome, Switch (one for each pier), ObservingConditions and SafetyMonitor
- No need to install ASCOM drivers
- Devices can be accessed simultaneously from different computers
- OS agnostic, works with Windows, Linux, Android, Mac OS, etc
- Mains voltage
- Battery voltage
- Motor current
- Weather
- External alarm
- Logged users
- Internet not available
- Temperature, humidity and dew point
- System CPU temperature
- Watchdog reboots system on hardware/software fails
- Sends Email on Fault or roof open/close
- ARO-Master box internal cool fan and heater control
- Up Time, number of minutes since the controller was initialized
- Up to 6 piers (one user per ‘pier’)
- Internet control of pier relays (4 relays per pier, 110/220v 10A per relay)
- No need for third-party ‘smart Wifi plugs’
- Relay reset with timed rearm
- Auto user logoff timer (turns off all relays)
- ‘Relay box’ is installed at each pier
- Daisy-chain UTP cable pier connection, easy and less cabling
- Power fail (Mains or Battery)
- Meteo event (rain, wind, lumens, clouds)
- External signal input (third-party control)
- Optional close at Astronomical Sunrise
- If ‘Emergency’ button pressed
- Setup option ‘Enabled’ is not active
- No Meteo source present
- No Users logged in
- No Internet detected
- Internal high current H-Bridge for DC motor control
- Manual Open and Close buttons
- Manual Emergency/stop button
- Roof open/close limit switch sensor input
- Roof moviment Timeout, if no position reatched (ex: limit switch fails) in the given time then stop motor
- Roof response Timeout, if no movement (ex: motor stall, jammed rack & pinion, blocked roof, etc) in the given time then stop motor
- Internal PWM motor control with programable Frequency, Start Duty, Max Duty and Acceleration
- External (third-party) motor control using relay signals
- Switching 12v power supply with 350W
- Integrated UPS for interrupted motor operation
- Integrated battery charger (external battery)
- Closes the roof securely even in the event of a complete power failure
Important
Since this system can also be used in an observatory with several independent piers and mounts, it is no longer practical to park one/all the mounts before moving the roof.
Therefore, the design of the observatory's sliding roof system must take into account the possibility of moving it regardless of the position of the telescopes, typically mounting the ceiling at a height that does not interfere with any of the installed OTAs, or using lower piers.
In Clamshell Domes type observatories the design itself allows the dome to be opened and closed without any concern about the OTA position.
Plase take a look ate the Hardware section and then the Software/Firmware section
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