small_tel/Daemons/domedaemon-astrosib/Readme.md

domedaemon‑astrosib

domedaemon‑astrosib is a daemon that controls an Astrosib all‑sky dome via a serial line. It provides a TCP/UNIX socket interface for clients, integrates with a weather proxy to enforce safety rules, and generates a FITS‑style header file with current dome status.

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Features

• Dome open/close – fully open or close the dome
• Stop movement – immediately stop any ongoing dome motion
• Independent cover control – open or close only the northern or southern cover
• Relay control – switch three auxiliary relays (power, light, etc.)
• Status reporting – cover states, encoder angles, relay states, rain sensor, motor currents, temperatures
• Weather integration – automatically closes the dome and prevents opening when weather is bad or data is stale
• Manual override – via SIGUSR1 (forbid) / SIGUSR2 (allow) signals
• FITS header file – writes current dome state into a FITS‑style header file (e.g., for later use by image processing pipelines)
• Network interface – supports both INET (TCP) and UNIX domain sockets
• Daemon mode – forks, writes PID file, restarts child on crash

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Command‑line options

Option	Argument	Default	Description
-h, --help	–	–	Show help
-d, --device	path	–	Full path to serial device (e.g. /dev/ttyUSB0)
-n, --node	string	55555	Node specification: port number for TCP, or path for UNIX socket
-l, --logfile	path	–	Full path to log file
-u, --unix	–	0	Use UNIX socket instead of TCP
-v, --verbose	–	0	Increase verbosity (each -v adds 1 level)
-p, --pidfile	path	/tmp/domedaemon.pid	PID file path
-H, --headerfile	path	/tmp/dome.fits	Output file for FITS‑style header
-N, --domename	name	Astrosib	Dome name inserted into the header

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Socket protocol

The daemon listens for text‑based commands on the configured socket. Each command returns one or more lines of output, terminated by newline (\n).

Commands

Command	Description	Example
unixt	Return server’s current UNIX time (seconds with two decimal places)	unixt → unixt=1704067200.12
status	Get dome status in old format (four numbers)	status → status=3,3,0,0
statust	Get dome status in human‑readable format	statust → (see example below)
relay1 … relay3	Get/set relay state (0 = off, 1 = on)	relay1 → relay1=1 (if queried without argument)
open	Fully open dome (only if weather permits and observations not forbidden)	open
close	Fully close dome	close
stop	Immediately stop dome movement	stop
half1 … half2	Get/set state of a single cover (0 = closed, 1 = opened)	half1 0

Each setter returns an OK answer in case of success or error code like BADVAL for bad value of setter.

Example statust response

status=3,3,0,0
operations=permitted
cover1=closed
cover2=closed
angle1=0
angle2=0
relay1=0
relay2=0
relay3=0
reqtime=1779087731.049449921

• operations can be permitted or forbidden (manual override).
• cover1 / cover2 report closed, opened or intermediate.
• angle1 / angle2 are encoder values (degrees).
• relay1 … relay3 show the current state of each relay.
• reqtime is the time when the status was last read from the hardware.

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Weather integration

The daemon retrieves weather data via the weather_proxy shared memory interface (get_weather_data()).
Safety rules:

• If weather.forceoff, weather.rain, or weather.weather > WEATHER_BAD → dome is closed and opening is blocked.
• If the weather data is older than 300 seconds (WEATHER_LOST) → treated as lost communication → dome is closed and blocked.
• When weather becomes good again, the daemon automatically resets the BadWeather flag and allows normal operation.

The weather is polled every 5 seconds (WEATH_POLL).

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Signal handling

Signal	Effect (in child process)
SIGUSR1	Forbid observations – close dome and block open
SIGUSR2	Allow observations – remove manual block
SIGTERM	Stop the daemon and remove PID file
SIGINT	Same as SIGTERM
SIGHUP	Same as SIGTERM

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FITS header file

The daemon writes a text file (default /tmp/dome.fits) with FITS‑like keyword/value pairs.
The file is updated every polling cycle (every 5 seconds) and can be used by external pipelines to record dome state.

Example content:

DOME    = 'Astrosib'            / Dome manufacturer/name
DOMESTAT= 'idle'                / Dome status
DOMECVR1= 'closed'              / Dome cover 1 status
DOMECVR2= 'closed'              / Dome cover 2 status
DOMEANG1= 0                     / Dome cover 1 angle
DOMEANG2= 0                     / Dome cover 2 angle
DOMERLY1= 0                     / Dome relay1 state
DOMERLY2= 0                     / Dome relay2 state
DOMERLY3= 0                     / Dome relay3 state
TDOMMEAS= 1779090474.704        / Measurement time: 2026-05-18 10:47:54

The file is created atomically using mkstemp() + rename().

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Building and dependencies

Dependencies

• libusefull_macros – common macros and helpers
• libweather_proxy – shared memory weather data
• pthread, libc

Build

git clone --depth=1 https://github.com/eddyem/small_tel.git
cd small_tel/Daemons/domedaemon-astrosib
mkdir build
cd build
cmake ..
make

The resulting binary is domedaemon.

Installation

Copy the binary to a suitable location (e.g. /usr/local/bin) or run sudo make install. It is recommended to run the daemon as a system service (using init script, e.g. in /etc/local.d/) so that it starts automatically at boot.

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Usage example

Start the daemon with a UNIX socket and weather‑aware header:

domedaemon -vv -d /dev/ttyS3 -l /var/log/telescope/domedaemon.log

Connect to the socket using socat, nc or my tty_term:

nc localhost 55555
> statust

Send SIGUSR1 to forbid observations (e.g. before maintenance):

killall -USR1 domedaemon

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Notes

• The serial protocol is specific to Astrosib hardware (commands like STATUS, OPENDOME, CLOSEDOME, STOPDOME, SHUTTERMOVEDEG, SWITCHTOGGILE are hard‑coded).
• Encoder values are reported as raw integers; interpretation depends on the physical setup.
• The daemon polls the dome every 5 seconds (T_INTERVAL). During that interval it also processes client requests and checks weather.
• If the serial device becomes unresponsive, the status will return an error and the header will not be updated.

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License

GNU General Public License v3.0 or later. See the LICENSE file in repository's root directory or http://www.gnu.org/licenses/ for details.