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, any problems that arises can be more easily resolved, 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 power 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 project started 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.
The software/firmware is fully proprietary and written in C/C++, it doesn't have dependencies on external libs or code. Remote control must be taken very seriously, all code must be fully under our control.
The main component, contains the electronics and plugs for connecting external components (motor, limit switches, battery, etc.)
- Switching power supply + UPS + BMS
- Can close roof even on mains power failure (needs external battery)
- High power DC motor controller
- Board with 8 relays (used to control system function)
- 2 relays to control opening and closing with external motor control system (eg: garage motors and similar)
- Main control board hat for Rpi 4/5
- 9 inputs (open limit, close limite, vent position, other switches & sensors)
- Manual Open and Close buttons
- Manual Emergency/stop button
- RJ12 for weather station connection and power
- Case fan, CPU fan control
- Case heater
- 4 x ADC for Power, Battery and supply monitoring
- I2C and UART interaces
- RJ45 Ethernet
- 2 x USB3
- 2 x USB2
- No software instalation needed
- Accessible from anywhere
- OS independent using Windows, Linux, Android or Mac browser
- Auto firmware updates
- Direct integration with uAstro SkyPatroll (MSP) or uAstro Weather Station (MWS)
- Mains voltage
- Battery voltage
- Rain or Cloud level
- Wind speed, Temperature, Humidity and Dew point
- Lux
- External alarm
- Logged users
- Internet not available
- System CPU temperature
- Sunrise
- Motor current
- Power fail (Mains or Battery)
- Meteo event (Rain, Humidity, Dew, Wind, Lumens, Clouds)
- External signal input (third-party control)
- Optional close at Astronomical Sunrise
- Optional close if no Weather info
- Optional close if no Internet
- Optional close if no Logged users
- ‘Emergency’ button pressed
- Setup option ‘Enabled’ is not active
- Roof open/close limit switch sensor input
- Roof Ventilation position
- 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
- Internal relays to control external motor systems (eg: garage motors and similar)
- Alpaca Discovery aware (no setup or configuration needed)
- Implements Alpaca devices Dome, Switch (system switches and pier relays), ObservingConditions and SafetyMonitor
- No need to install ASCOM drivers
- Devices can be accessed simultaneously from different computers
- Watchdog reboots system on hardware/software fails
- Sends Email on Fault or roof open/close
- ARO-Master box internal cool fan and heater control
- Other input/relay functions can be implemented (requires programming)
- Depending on the system configuration, up to 32 pier power relays can be controlled.
- Pier power relay reset with timed rearm (for pier reboot)
- Auto user logoff timer (turns off pier relay)
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
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 of the ARO-Master box that can be purchased, in addition there is also extra hardware that can be purchased by end users, such as the rack and pinion and motor for roof movement. . .