# domedaemon_baader **domedaemon_baader** is a daemon that controls a [**Baader Planetarium**](https://www.baader-planetarium.com/) 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 and weather sensor data. --- ## Features - **Dome open/close** – fully open or close the dome - **Stop movement** – immediately stop any ongoing dome motion - **Weather sensor integration** – reads rain/cloud status from the dome’s internal sensor - **Error reporting** – reports rain, timeout, and power‑loss error codes - **Weather proxy integration** – automatically closes the dome and blocks opening when external weather is bad or data is stale - **Manual override** – via `SIGUSR1` (forbid) / `SIGUSR2` (allow) signals - **FITS header file** – writes current dome state and weather sensor status 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 --- ## Command‑line options | Option | Argument | Default | Description | |----------------------|-------------------|---------------------------------|----------------------------------------------------------------------------| | `-h`, `--help` | – | – | Show help | | `-d`, `--serialdev` | *path* | – | Full path to serial device (e.g. `/dev/ttyS1`) | | `-n`, `--node` | *string* | – | Node specification: IP, `name:IP`, or path for UNIX socket. For anonymous UNIX socket use `\0path` or `@path`. | | `-l`, `--logfile` | *path* | – | Full path to log file | | `-u`, `--unixsock` | – | 0 | Use UNIX socket instead of INET | | `-v`, `--verbose` | – | 0 | Increase verbosity (each `-v` adds 1 level; 0: only errors, 1: +warnings, 2: +messages, 3: +debug info) | | `-p`, `--pidfile` | *path* | `/tmp/domedaemon.pid` | PID file path | | `-H`, `--headerfile` | *path* | `/tmp/dome.fits` | Output file for FITS‑style header | | `-N`, `--domename` | *name* | `Baader` | Dome name inserted into the header | | `-b`, `--baudrate` | *speed* | 9600 | Serial baud rate | | `-T`, `--sertmout` | *microseconds* | 5000 | Serial read timeout (µs) | | `-m`, `--maxclients` | *number* | 2 | Maximum number of simultaneously connected clients | --- ## 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 | |---------------------------------|-----------------------------------------------------------------------------|----------------------------------------------| | `open` | Fully open dome (only if weather permits and observations not forbidden) | `open` | | `close` | Fully close dome | `close` | | `stop` | Immediately stop dome movement | `stop` | | `status` | Get dome status and temperatures | `status` → (see example below) | | `weather` | Get weather sensor status | `weather` → `weather=good` | | `dtime` | Return server’s current UNIX time (seconds with milliseconds) | `dtime` → `UNIXT=1704067200.123` | | `help` | Show available commands (default handler) | `help` | Each setter returns an `OK` answer in case of success or error code like `BADVAL` for bad value of setter. ### Example `status` response ``` status=opened measuret=1704067200.123 error=closed@timeout@powerloss FORBIDDEN BADWEATHER errored_command=open ``` - `status` can be `opened`, `closed`, `intermediate` or `unknown`. - `measuret` is the time when the status was last read from the hardware. - `error` appears when the dome reports an error. It encodes up to three flags: - `closed` – base error (dome closed due to error) - `@rain` – rain sensor triggered - `@timeout` – watchdog timeout - `@powerloss` – power loss detected - `FORBIDDEN` appears when observations have been manually disabled (`SIGUSR1`). - `BADWEATHER` appears when weather proxy reports unsafe conditions. - `errored_command` shows the last command that failed. --- ## Weather integration The daemon retrieves external 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** (`T_INTERVAL`). --- ## Dome‑internal weather sensor The daemon also reads the dome’s built‑in weather sensor via the `d#ask_wea` command. Possible states: - `0` → `good` (no rain/clouds) - `1` → `rain/clouds` - other → `unknown` This status is written into the FITS header as `DOMEWEAT`. --- ## 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` | | `SIGQUIT`| Same as `SIGTERM` | --- ## 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: ``` OPERATIO= 'FORBIDDEN' / Observations are forbidden DOME = 'Baader' / Dome manufacturer/name DOMESTAT= 'closed' / Dome status DOMEWEAT= 'good' / Dome weather sensor status DOMEECOD= 0 / Dome error code: Rain|Watchdog|Power TDOMMEAS= 1779091627.907 / Measurement time: 2026-05-18 11:07:07 ``` The `OPERATIO` keyword appears only when observations are manually forbidden via `SIGUSR1`. The file is created atomically using `mkstemp()` + `rename()`. --- ## Building and dependencies ### Dependencies - [libusefull_macros](https://github.com/eddyem/snippets_library) – common macros and helpers - [libweather_proxy](https://github.com/eddyem/small_tel/tree/master/Daemons/weather_proxy) – shared memory weather data - `pthread`, `libc` ### Build ```bash git clone --depth=1 https://github.com/eddyem/small_tel.git cd small_tel/Daemons/domedaemon_baader make ``` The resulting binary is `domedaemon`. ### Installation Copy the binary to a suitable location (e.g. `/usr/local/bin`). 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. --- ## Usage example Start the daemon with a TCP local-only socket and weather‑aware header: ```bash domedaemon -d /dev/ttyS2 -l /var/log/telescope/domedaemon.log -vv \ -n localhost:55555 -H /tmp/dome.fitsheader ``` Connect to the socket using `socat`, `nc` or my [`tty_term`](https://github.com/eddyem/tty_term): ```bash nc localhost 55555 > status ``` Send `SIGUSR1` to forbid observations (e.g. before maintenance): ```bash killall -USR1 domedaemon ``` Don't send signals USR1/USR2 to father process (its PID stored in pidfile): it simply ignores them. Send them by `killall` to both processes, or by `kill` to daughter process. --- ## Notes - The serial protocol is specific to Baader Planetarium hardware. Commands such as `d#opendom`, `d#closdom`, `d#stopdom`, `d#get_dom`, `d#ask_wea`, and `d#warning` are hard‑coded in `commands.h`. - The dome returns numerical values: - Position codes: `1111` = fully opened, `2222` = fully closed, anything else = intermediate. - Weather codes: `0` = good, `1` = rain/clouds, other = unknown. - Error codes are bit‑encoded: `1` = rain, `10` = timeout, `100` = power loss. - The daemon polls the dome every **5 seconds** (`T_INTERVAL`). During that interval it also processes client requests and checks external weather. - If the serial device becomes unresponsive, the status will show `unknown` and the header will not be updated. --- ## License **GNU General Public License v3.0** or later. See the `LICENSE` file in repository's root directory or for details.