AvNav server configuration

Introduction

Linux/Raspberry/Windows

When starting up, the AvNav server reads its configuration from an XML file named avnav_server.xml.
This file is typically located at /home/pi/avnav/data on the Raspberry Pi, or $HOME/avnav on other systems. On Windows, the file is located in the user profile folder named avnav.

The entries in this file allow for extensive customization of the AvNav server's behavior. In normal cases, you do not need to edit this file directly; instead, you can edit the Server Configuration within AvNav. Details regarding individual functional units can be found under Configuration Linux/Windows.

Android

On Android, the AvNav server configuration is stored in the app's user data. Generally, this cannot be viewed on Android – therefore, only the Configuration within AvNav is available for adjustments. In principle, the server in the Android version largely shares the same functions as the other versions. However, the names of the individual functional units may differ in some cases. Details regarding the functional units can be found under Configuration Android.

Configuration within AvNav

In AvNav, the server's corresponding behavior can be adjusted in various sections.

If the Server tab is not directly visible, you can access it via the button or by swiping.

In the server section, the server components (handlers) required for the respective function are listed (in the example: Router). If a handler can be edited, the corresponding button is provided.

This opens a dialog for the settings.

The parameters that can be edited here correspond to the properties of the nodes in the avnav_server.xml file on Linux and Windows.

When settings are saved using , they take effect immediately. On Linux/Raspberry/Windows, they are saved in the avnav_server.xml file, and on Android, they are saved in the user data.

Connections page

All incoming and outgoing (NMEA) connections can be configured via

->

New connections can also be created here. See also the Details on Connections.

Server page

For an overview of all server functions, you can use the page

->

After opening, only the functional units (handlers) that are not visible on other pages are displayed initially. You can display all of them using .

Using , new handlers can be added if they support this. Usually, these are handlers for new connections.

Description of functional units (Linux/Windows)

Initial values and error handling

If the avnav_server.xml file does not exist during the first start, it is created from a template – suitable for the Raspberry or other systems. This template is the file /etc/avnav_server.xml on the Raspberry Pi. If this file does not exist, a file from the package is used as a template.
If AvNav is started from the command line using the "avnav" command, a template can be specified with the -t option.

Generally, this file is not modified during AvNav software updates. However, it may happen that new entries are required for new features. In that case, this will be noted in the Release Notes.

With every successful start, AvNav writes a copy of this file with the extension .ok. If parsing the XML file fails during the next start, AvNav will read the .ok file instead. This function is designed to prevent a failed start after a change that AvNav might have made itself in certain situations.

If AvNav cannot start due to configuration errors, you should completely remove the avnav_server.xml and restart. AvNav will then start again from a "clean" template.

Special values

In the following descriptions, the "online" column indicates whether parameters can be changed directly within AvNav.

If parameters that are not directly editable need to be changed, the avnav-update-plugin should be used to edit the file directly in the browser.
The plugin can be reached on the ->.

If you make changes to the avnav_server.xml directly using an editor, AvNav must be restarted afterward. If AvNav is running as a system service, you do this with the command

sudo systemctl restart avnav

However, it is recommended to start AvNav from the command line first after a change to see if there are any major errors. The command sequence is then:

sudo systemctl stop avnav  
avnav -e  
^C  
sudo systemctl start avnav

The -e option prevents the avnav_server.xml.ok from being loaded in case of an error. The key combination ^C aborts the running AvNav instance.

NMEA filter

Filters can be specified in various places to influence which NMEA data is allowed to pass through and which is not.

Comma-separated NMEA messages can be specified here. To make them independent of Talker IDs, the 2 characters after a $ are ignored.

A filter for $GPRMC looks like this: $RMC. If a ^ is placed in front of the filter, it is negated; thus, ^$RMC means: no RMC records. AIS data can be matched with the filter ! or !AIVDM.

Examples:

! - only all AIS messages
^! - no AIS messages
$RMC,$RMB - RMC and RMB records
!,$RMC - all AIS messages and RMC records
^$APB,^$RMB - no APB and no RMB records

BlackList

A blacklist contains the names of input channels (handlers) whose data should not be output on the respective interface. Multiple entries are separated by a comma.

Functional units (handlers)

Inside the configuration, there are entries for individual handlers.

Basically, there are 3 categories of such handlers:

Parts that may only appear exactly once, but must absolutely be in the avnav_server.xml
Parts that normally do not need to be in the avnav_config.xml, only if something special needs to be configured
Examples: AVNAlarmHandler, AVNChartHandler,...
Parts that can appear once or multiple times in the avnav_server.xml. These are primarily the input and output channels. If no such entry exists, the function is not available.

There are some properties that appear in multiple components; here is an explanation for them.

Name	Description	Example
enabled	Many handlers can be switched on or off on the Server/Status page using this parameter	on
name	Name of an input or output channel. This is displayed on the status page and can also be used in the blackList parameter for filtering	nmea0183tosignalk
filter	NMEA filter
readFilter	For combined readers/writers: Filter for the input side. See filter
blackList	List of channel names whose data should not be sent out. Observe spelling (capital L)	nmea0183tosignalk
priority (since 20220421)	All NMEA input channels have a priority field. This influences which value wins if the same values are decoded by multiple channels. The default priority is 50; it can be increased or decreased. The SignalK integration has a default priority of 40.	50

Below are the most important components with their parameters. If parameters are not described here but might appear in a template, they should be left as they are.

AVNConfig

Basic configuration and system time, Category 2 (1x, optional)

Name	Online	Description	default/template
settimecmd		A command called to set the system time. The parameter is a timestamp in UTC, as required for date -u	only set with the avnav-raspi package
settime (from 203304xx)	X	If on, set the system time (settimecmd must also be set)	on
maxtimeback	X	Maximum time the system time is set backward before all internal data is deleted (s)	5
systimediff	X	Maximum deviation of the system time from the GPS time before the system time is reset (s)	5
settimeperiod	X	Time (in s) before the system time is reset again	3600
ntphost (from 20220421)	X	An NTP server. This is queried if no valid GPS time is available and settime is active	pool.ntp.org
switchtime (from 20220421)	X	Time (in s) to wait at least after setting the time before switching from GPS to NTP or vice versa. This time is also used to wait for a valid GPS time after startup	60
expiryTime	X	Time (in s) for how long received NMEA data remains valid	30

AVNAisWorker

AIS configuration, Category 2 (1x, optional)

Name	Online	Description	default/template
ownMMSI	X	MMSI of your own boat, this is filtered out from the AIS data
aisExpiryTime	X	Time (in s) for how long received AIS data remains valid	1200

AVNDecoder

Decoder, Category 2 (1x, optional)

Name	Online	Description	default/template
decoderFilter	X	Filter for the decoder

AVNQueue

The internal NMEA queue. Category 2 (once, optional).

Name	Online	Description	default/template
maxList	X	Max. number of NMEA records in the queue	300
maxAge	X	Max. age (in s) of an entry in the queue. Older entries are deleted. This prevents data from being sent out too slowly.	3

AVNHttpServer

The internal HTTP server. Category 2 (once, optional).

The parameters cannot be changed within AvNav. In addition to the parameters for AVNHttpServer, there are some deeper entries that can repeat multiple times. Normally, no changes should be necessary here (Directory, MimeType).

Except for the HTTP port, no changes should normally be necessary.

Parameters for AVNHttpServer

Name	Description	default/template
httpPort	The port on which the HTTP server accepts requests	8080
httpHost	The bind address; you can restrict this to a specific network here	0.0.0.0

Parameters for Directory

These values are usually overwritten by the call (parameter -u for avnav) and should not be changed.

Name	Description	default/template
urlpath	The URL (without /)
path	The actual path on the system

Parameters for MimeType

Here, mime types are configured for file extensions. If your own application requires something special, you can add it here.

Name	Description	default/template
extension	File extension (e.g., .avt)
type	Mime type (e.g., text/plain)

AVNBlueToothReader

Reading from Bluetooth devices with serial profile. Category 3 (once possible, optional)
Only possible if the device has a Bluetooth device.

Name	online	Description	default/template
maxDevices	X	Maximum number of simultaneously connected Bluetooth devices	5
deviceList	X	Comma-separated list of Bluetooth device IDs. If set, only these devices will be connected.
filter	X	filter for NMEA data
name	X
enabled	X
priority	X

AVNSerialReader

Reading from serial devices. Category 3 (multiple, optional). This reader should only be used for devices connected directly via hardware (UART); for devices connected via USB, the AVNUsbSerialReader is responsible.

Name	online	Description	default/template
name	X	Channel name for use in a BlackList and for display	internally generated name
port	X	Device name, e.g., /dev/ttyAMA0
baud	X	Baud rate. If minBaud is also specified, this is the maximum baud rate used for automatic baud rate detection	4800
minbaud	X	Minimum baud rate used for automatic detection. If not set or 0, automatic detection is switched off
timeout	X	Timeout (in s) after which the device is closed and reopened without data	2
bytesize	X	Serial byte size	8
parity	X	Parity	N
stopbits	X	Number of stop bits	1
xonxoff	X	Usage of xon/xoff protocol (0: off)	0
rtscts	X	RTS/CTS usage (0: off)	0
numerrors	X	Number of errors after which the device is closed and reopened	20
autobaudtime	X	Time (in s) spent attempting to detect a newline in the data (during automatic baud rate detection)	5
filter	X	NMEA filter, see filter
enabled	X
priority	X

AVNSerialWriter

Output via a serial device. Also combined input and output. Category 3 (optional)
Only for direct serial devices, not for USB converters (use the AVNUsbSerialReader instead)

Name	online	Description	default/template
name	X	Channel name
combined	X	If "true", then both input and output simultaneously	false
readFilter	X	Filter for input direction. The parameter "filter" refers to the output direction!
blackList	X	blackList, comma-separated list of channel names whose data should not be output.
....		all parameters of AVNSerialReader

AVNUsbSerialReader

Handles serial devices connected via USB. Category 3 (once, optional).
This worker searches for all devices connected via USB. It attempts to open those with a serial profile, automatically set the baud rate, and then read NMEA data. Thus, such devices are usually recognized completely automatically by AvNav.
You can define rules for individual devices to treat them specifically. An ID that identifies the corresponding USB port is used for device identification. The easiest way to determine this ID is to watch the Connections Page while plugging in the device.

The parameters are divided into 2 parts:

Attributes for the entry itself
Subordinate entries of type UsbDevice

Example:

<AVNUsbSerialReader maxDevices="5" allowUnknown="true" baud="38400" minbaud="4800">
<UsbDevice usbid="1-1.2.1:1.0" baud="38400" minbaud="4800" filter="$RMC"/>  
</AVNUsbSerialReader>

Parameters for AVNUsbSerialReader

Name	online	Description	default/template
maxDevices	X	Maximum number of simultaneously connected USB devices	5
allowUnknown	X	Only if this entry is "true" are devices included that are not explicitly configured with UsbDevice	true
...	X	All parameters of AVNSerialReader except for port. These are set for devices that are not explicitly configured.

Parameters for UsbDevice

Name	online	Description	default/template
usbid	X	USB port identification e.g. "1-1.2.1:1.0", required
type	X	Type of device: reader, writer, combined, ignore. Set to ignore if the device should not be used	reader
...		all parameters of AVNSerialReader if type = "reader" (except port, which is set internally)
...		all parameters of AVNSerialWriter if type is combined or writer (except port, which is set internally)

AVNUdpReader

Opens a UDP port and processes incoming data. Category 3 (optional, multiple).

Name	online	Description	default/template
name	X	Channel name for use in blackList and in the display	internally calculated
port	X	UDP port
host	X	Bind address for the port. This allows limiting reception to localhost, for example.	0.0.0.0
minTime	X	If set: waiting time (in s) before another data record is received. This can be used to limit the data rate.	0
filter	X	Filter for NMEA data
enabled	X
priority	X
stripLeading	X	Remove all characters before $ or ! in a line.	off
joinMulticast	X	Joins a Multicast group, enabling the reception of multicast messages.	off
multicastAddr	X	Multicast address. This enables the reception of multicast messages on this address.	224.0.0.1

AVNUdpWriter

Sends NMEA data via UDP. Category 3 (optional, multiple)

Name	online	Description	default/template
name	X	Channel name	internally calculated
port	X	UDP target port	2000
host	X	UDP target address	localhost
filter	X	Filter for NMEA data sent
broadcast	X	Must be set to true if data should be sent as a broadcast	false
blackList	X	BlackList for channel names whose data should not be sent
enabled	X

AVNSocketWriter

An output that waits for connections on a port and outputs NMEA data to them (TCP server). Category 3 (multiple, optional).

Name	online	Description	default/template
name	X	Channel name	internally calculated
port	X	The listener port
address	X	If set, bind to this address (otherwise any: 0.0.0.0)
filter	X	Filter for NMEA data
read	X	If true, data is also read from the socket	false
priority	X	Only if read is active
readFilter	X	If reading, NMEA-Filter for the input direction
blackList	X	BlackList: Comma-separated list of channel names for which no data is output
minTime	X	Minimum time (in s) between 2 sent messages. This can be used to limit the data rate.	0
avahiEnabled	X	If switched on, the service is advertised via avahi as _nmea-0183._tcp	off
avahiName	X	The name for the Avahi service	avnav-server
enabled	X
sendOwn	X	send received data on the same connection	off

AVNSocketReader

An input that connects to a TCP server and reads data from there (TCP client). Category 3 (multiple, optional)

Name	online	Description	default/template
name	X	Channel name	internally calculated
port	X	TCP port to which a connection is established
host	X	TCP target address to which a connection is established
timeout	X	Connection timeout in s	10
minTime	X	Minimum time between 2 received messages	0
filter	X	Filter for NMEA data	empty
writeOut	X	send NMEA data on this connection	off
writeFilter	X	Filter for sent NMEA data	empty
blackList	X	Comma-separated list of source names whose data is not sent	empty
enabled	X
priority	X
stripLeading	X	Remove all characters before $ or ! in a line.	off
sendOwn	X	send received data on the same connection	off

AVNNmea0183ServiceReader

This handler is very similar to the AVNSocketReader. However, instead of configuring host and port, the name of the service is configured here. AvNav searches the network for MDNS/Bonjour/Avahi services of type _nmea-0183._tcp. If the entry is made via the web interface, AvNav offers a list of found services for selection. With this handler, a connection can be re-established even if, for example, IP addresses change.

Name	online	Description	default/template
serviceName	X	The name of the service (AvNav offers a list)	--
timeout	X	Connection timeout in seconds	10
minTime	X	Minimum time between 2 received messages.	0
filter	X	Filter for NMEA data	empty
writeOut	X	send NMEA data on this connection	off
writeFilter	X	Filter for sent NMEA data	empty
blackList	X	Comma-separated list of source names whose data is not sent	empty
sendOwn	X	send received data on the same connection	off
name	X
priority	X
enabled	X

AVNBME280Reader

Reader for the BME280 sensor via I2C. Category 3 (optional)
Writes MDA and XDR data sets.
Only visible if the python3-smbus package is installed.

Name	online	Description	default/template
name	X	Channel name	internally calculated
addr	X	I2C address of the sensor	0x77
interval	X	Time between 2 NMEA data sets in s	5
writeXdr	X	Write XDR if true	true
writeMda	X	Write MDA if true	true
namePress	X	XDR transducer name for air pressure	Barometer
offsetPress	X	Add this value (in hPa) to the measured pressure	0
nameHumid	X	XDR transducer name for humidity	Humidity
nameTemp	X	XDR transducer name for temperature	TempAir
enabled	X
priority	X

AVNBMB180Reader

Reader for the BMP180 sensor via I2C. Category 3 (optional)
Writes MDA and XDR data sets.

Name	online	Description	default/template
name	X	Channel name	internally calculated
addr	X	I2C address of the sensor	0x77
interval	X	Time between 2 NMEA data sets in s	5
writeXdr	X	Write XDR if true	true
writeMda	X	Write MDA if true	true
namePress	X	XDR transducer name for air pressure	Barometer
offsetPress	X	Add this value (in hPa) to the measured pressure	0
nameTemp	X	XDR transducer name for temperature	TempAir
enabled	X
priority	X

AVNSenseHatReader

Reader for the "SenseHat" add-on board via I2C. Category 3 (optional)
Writes MDA and XDR data sets.
Requires the python3-sense-hat package.

Name	online	Description	default/template
name	X	Channel name	internally calculated
interval	X	Time between 2 NMEA data sets in s	5
writeXdr	X	Write XDR if true	true
writeMda	X	Write MDA if true	true
namePress	X	XDR transducer name for air pressure	Barometer
offsetPress	X	Add this value (in hPa) to the measured pressure	0
nameHumid	X	XDR transducer name for humidity	Humidity
nameTemp	X	XDR transducer name for temperature	TempAir
nameRoll (from 20220421)	X	XDR transducer name for roll	Roll
namePitch (from 20220421)	X	XDR transducer name for pitch	Pitch
enabled	X
priority	X

AVNTrackWriter

Writing tracks in GPX format and a simple ASCII format. Category 2 (once, optional)

Name	online	Description	default/template
interval	X	Minimum distance in s between writing 2 entries	10
mindistance	X	Minimum distance in m between 2 track points	50
trackdir	X	Directory for tracks	/tracks
cleanup	X	Maximum length of the internally stored track in hours. Track data continues to be written to files, but the app can receive a maximum of this time (backwards) as a track.	25
writeFile	X	Write a track file. If switched off, recording only in memory.	on

AVNRouter

Managing routing data (waypoints, routes, anchor alarm). Calculation of data for autopilots. Category 2 (once, optional).

Name	online	Description	default/template
name	X	Channel name (used for AP data)	internally calculated
routesdir		Directory for routes	/routes
interval	X	Interval (in s) between RMB data sets	5
computeRMB	X	Calculate an RMB data set when a waypoint is active	true
computeAPB	X	Calculate an APB data set	false
useRhumbLine	X	Use the rhumb line mode for routes	false
nextWpMode	X	Selection of the next waypoint advance mode in a route (late, 90, early)	late
nextWpTime	X	The waiting time after the waypoint alarm (in seconds) until advancing to the next waypoint (only nextWpMode = early)	10

AVNNmeaLogger

Writes NMEA logs into the track directory. Category 3 (once, optional).

Name	online	Description	default/template
maxfiles	X	Number of files (1 per day) kept	100
filter	X	Filter for NMEA data	"$RMC,$DBT,$DBP"
interval	X	Minimum time in s before a set of the same type is written again	5
enabled	X

AVNImporter

Imports charts that still need to be converted. Category 2 (once, optional)

Name	online	Description	default/template
filesettle	X	Time in s waited after finding a file in the import directory before the converter starts	30
dirsettle	X	Time in s waited after finding a directory in the import directory before the converter starts	10
scanInterval		Time (in s) between 2 automatic scans of the import directory. 0: no automatic scan (triggered when uploading)	0
enabled	X

AVNWpaHandler

Configuration of external WLAN connections to the Raspberry Pi. (Legacy: not for versions after Debian Trixie). Category 3 (once, optional)

Name	Description	default/template
wpaSocket	The control connection to wpa_supplicant	/var/run/wpa_supplicant/wlan-av1
ownSsid	Own SSIDs; these are hidden	avnav,avnav1,avnav2
firewallCommand	If configured, external access can be enabled via a WLAN	sudo -n $BASEDIR/../raspberry/iptables-ext.sh wlan-av1

AVNCommandHandler

Executing commands, e.g., for alarms. Category 2 (once, not necessary).

The AVNCommandHandler itself has no parameters. However, various commands can be configured and then addressed by name. The default configuration is:

<AVNCommandHandler>
<Command name="sound" command="mpg123 -q" repeat="1"/>
</AVNCommandHandler>

Parameters for Command

Name	Description	default/template
name	Name of the command
command	Command to be executed
repeat	Number of repetitions	1

AVNCanboatHandler

This handler controls the connection to canboat. When starting AvNav on older images (< trixie), it is checked whether canboat-rust is installed or only canboat. If only canboat is available, the configuration for canboat must partially take place outside of AvNav (see the legacy documentation). In this case, the default for the canboatType parameter is set to legacy.

In the AvNav interface, some parameters are hidden in this case – these are marked with an *.

Name	Description	default/template
canboatType	`rust` or `legacy`. This value cannot be changed in AvNav (only in avnav_server.xml).	rust
canboatKind *	The parameter --kind for canboat	socketcan
canboatDevice *	The parameter --device for canboat. The value depends on the kind, e.g., can0
canboatParam *	Free parameters for canboat
canboatNMEA *	Open a connection and receive NMEA0183 data	on
nmeaPort *	The port used for NMEA0183 data	2607
filter *	An NMEAfilter for the received NMEA0183 data.
readN2K	Open a connection and read NMEA2000 data directly in JSON format.	off
port	The port for the NMEA2000 JSON connection	2598
autoSendRMC	If not 0, AvNav generates RMC data sets if no such sets are already present in the NMEA data	5
timeInterval	Time interval in seconds for reading time from NMEA2000. This is also the interval for the generated RMC data.	0.5
timePGNs	The PGNs used for time	129029, 126992
priority	The priority for the injected data. Data received via readN2K uses priority + 1	40

AVNAlarmHandler

Management of alarms. Category 2 (once, not necessary).

The default configuration is:

<AVNAlarmHandler>
<Alarm name="waypoint" category="info" repeat="1"/>  
 <Alarm name="connectionLost" category="info" repeat="1"/>
<Alarm name="anchor" category="critical" repeat="20000"/>
<Alarm name="gps" category="critical" repeat="20000"/>
<Alarm name="mob" category="critical" repeat="2"/>  
</AVNAlarmHandler>

Starting from version 20220421, existing alarm entries in avnav_server.xml should be deleted unless a special command is to be entered there.
This allows sounds to be defined via sound selection for the category.

If special commands are to be triggered with alarms, these can be explicitly set in the avnav_server.xml.

<AVNAlarmHandler>  
 <!-- legacy way of configuring alarms - still supported but not recommended, use category at least and optionally parameter -->
<Alarm name="gps" category="critical" command="gpsAlarm" parameter="$BASEDIR/../sounds/anchorAlarm.mp3" repeat="20000"/>  
 <!-- with the next line we configuer a special command that will be called when we receive a "sinking" notification from SignalK  
 the sound is determined by the category - and this is also the parameter that the command will receive -->
<Alarm name="sk:sinking" command="sinkingAlarm" category="critical" repeat="2"/>  
</AVNAlarmHandler>

Parameters for Alarm

Name	Description	default
name	Name of the alarm	empty, required
category	Category (info, critical)	empty
command	Command to be executed (must be configured in AVNCommandHandler)	empty
autoclean	Switch off the alarm when the command has finished	off
sound	The name of a sound file – if specified, this is used (relative names refer to the internal sound directory or the user directory). If not set, the sound is determined from the category or, if not set, from the 'parameter'	empty
repeat	Number of command (and sound) repetitions	1
parameter	If specified, this parameter is passed to the command. If neither sound nor category are set, the name is interpreted as the path to a sound file.

Parameters for AlarmHandler

Name	online	Description	default/template
infoSound	X	Name of an MP3 file for the sound in the info category. Can be selected from a list of built-in sounds and files in the user directory (uploadable via the download page)	waypointAlarm.mp3
criticalSound	X	Name of an MP3 file for the sound in the critical category. Can be selected from a list of built-in sounds and files in the user directory	anchorAlarm.mp3
defaultCommand	X	Command for alarms that do not have an explicitly defined command. This command must be configured in AVNCommandHandler.	sound
stopAlarmPin	X	Only on Raspberry Pi: If set (board numbering), a low on this GPIO pin turns off alarms. Starting with version 2025xxxx, there is a separate plugin "resetAlarm"; configuration must be performed there. An existing setting is migrated during installation.	empty

AVNPluginHandler

Management of plugins. Category 2 (once, optional).
The AVNPluginHandler manages plugins, which can be installed in different directories. There are 3 directories where plugins are searched:

builtin: /usr/lib/avnav/server/plugins
system: /user/lib/avnav/plugins
user: $DATADIR/plugins

In addition to the parameters for the plugin handler itself, the respective plugins can expect parameters. The name for the plugin results from the category and the plugin directory. Example:

<AVNPluginHandler>
<builtin-canboat enabled="true" allowKeyOverwrite="true" autoSendRMC="30" sourceName="canboatgen"/>
</AVNPluginHandler>

Parameters for AVNPluginHandler

Name	Description	default/template
builtinDir	Directory for built-in plugins, cannot be changed	/usr/lib/avnav/server/plugins
systemDir	Directory for plugins installed as separate packages	/usr/lib/avnav/plugins
userDir	Directory for user plugins	$DATADIR/plugins

Parameters for builtin-canboat

Name	online	Description	default/template
enabled	X	Only active if true	off
allowKeyOverride	X	Must be set if date and time are to be read from canboat	off
port	X	canboat json port	2598
host	X	Host for the n2kd	localhost
autoSendRMC	X	If no RMC is seen in the NMEA data stream for this time (in s), but valid position data + time from canboat are available: send RMC (is important for date/time on NMEA0183)	0 (off)
readPos	X	Read position from PGN 129025 and COG/SOG from PGN 129026	on
sourceName	X	Channel name used for RMC	plugin-name
timeInterval	X	Minimum time between 2 NMEA2000 time values before they are saved (seconds)	0.5
timePGNs	X	PGNs used for setting the time	126992,129029

Parameters for system-resetAlarm (only with the avnav-raspi-base package)

Name	online	Description	default
gpio	X	GPIO pin (board numbering) where a button to reset alarms is connected	--
lowActive	X	If set, the input is L-active, i.e., alarms are reset with a low at this input	true
pullUpDown	X	If set, a pull-up or pull-down resistor is activated for the input so that only an external button needs to be connected.	true

AVNChartHandler

Management of charts. Category 2 (once, does not have to be included)

Name	Description	default/template
period	Time interval between 2 read processes for the chart directory (seconds)	30
upzoom	Number of zoom levels above the highest available level	2

AVNUserHandler

Management of user files. Category 2 (once, does not have to be included)

Name	Description	default/template
interval	Time interval between 2 read processes for the directory (seconds)	5

AVNImagesHandler

Management of user images. Category 2 (once, does not have to be included)

Name	Description	default/template
interval	Time interval between 2 read processes for the directory (seconds)	5

AVNUserAppHandler

Management of the configured UserApps. Category 2 (once, does not have to be included)

This handler is somewhat special. Initially, no configurations can be found here, but configurations can be created via the WebApp. Manual changes are not recommended.

AVNAvahiHandler

Controls the registration of AvNav with Avahi (MDNS/Bonjour).

Name	online	Description	default/template
serviceName	X	The name that becomes visible in Tools. This is not the host name that you use in avnav.local!	avnav
maxRetries	X	Number of repetitions if the selected name is already taken. Repetitions append a "-nn" suffix to the name.	20
timout	X	Timeout when connecting to the avahi daemon (in s)	10
enabled	X

AVNSignalKHandler

For a description, see the SignalK documentation.

Description of functional units (Android)

Some parameters appear in multiple handlers:

Name	Description	default
enabled	activates/deactivates this handler	depends on handler
name	name for the handler. This can be used in blacklists.	empty
port	TCP or UDP port
filter/readerFilter/ sendFilter	This is an NMEA filter. Here it can be defined which NMEA data is passed through. Multiple filters are separated by a comma (,). For data sets starting with the dollar sign ($), the next two characters are ignored (the Talker-Id). A filter for all RMC sets looks like this: $RMC. For all AIS data: !. All RMC and RMB sets: $RMC,$RMB. If the filter should be negated, a ^ must be placed in front of the expression. ^$RMB,^$APB	empty
blacklist	a comma-separated list (,) of names. NMEA data from these sources are not sent out.
priority	If this handler reads (or generates) data, it is potentially read by the decoder and written to AvNav's internal memory. If multiple handlers provide the same data (e.g., position), it must be decided which should be written to the internal memory. This setting is used for this. Data with higher priority wins.
queueAge	AvNav has an internal queue that picks up received data and passes it on to the outputs. If an output is too slow, it may not be able to forward all incoming data immediately, and they remain in the queue for a longer period. If the data is older than the time set here (in ms), they are deleted from the queue.	3000

The existing "handlers" and their parameters are described below. Only the specific parameters are described.

Decoder

Parameter	Description	default
ownMMSI	own MMSI, this is hidden in the AIS display	empty
posAge	allowed age for the GPS position (in sec); after this time, the entry is deleted if no new GPS data has been received	10
nmeaAge	allowed age for NMEA data (in sec) that does not contain position data	600
aisAge	allowed age for AIS data (in sec)	1200

Route

Parameter	Description	default
computeRMB	generate NMEA-RMB data sets when routing is active.	on
computeAPB	generate NMEA-APB data sets when routing is active	on
useRhumbLine	set the routing mode to rhumbLine	off
nextWpMode	set the mode for waypoint advancement - late/early/90	late
nextWpTime	in "early" mode, the time (in s) after the waypoint alarm until advancing to the next waypoint	10

Track

Parameter	Description	default
interval	Interval (in sec) for writing the track as a "gpx" file.	300
distance	Minimum distance (in m) before a new track point is written	25
minTime	Minimum time (in sec) before a new track point is written	10
length	Length of the displayed track in hours (h).	25

Logger

NMEA-Logger

WebServer

Parameter	Description	default
port	the TCP port on which the server accepts connections.	8080
external	If active, other devices can also connect (otherwise only on the own device). Note: This parameter should be enabled with caution and only in trusted networks. There is no further protection within the app!	off
mdnsEnabled	makes the service known via "mDNS" (Bonjour).	on
mdnsService	The name under which the app is accessible via mDNS/Bonjour.	avnav-android

InternalGPS

The GPS of the device.

MDNSResolver

The handler for resolving and advertising "mDNS" (Bonjour/Avahi) services.

Remote Channel

The handler for remote control.

TcpReader

Parameter	Description	default
ipAddress	The IP address or the hostname for the server to be contacted. This can also be an mDNS name such as avnav.local.	---
port	The IP port to which a connection should be established.	---
sendOut	If active, NMEA data is also sent. Otherwise, only received.	off
readTimeout	Mark the connection as inactive if no data has been received after the set time (sec).	10
writeTimeout	Close the connection if an NMEA data set could not be written within the set time (sec).	5
connectTimeout	Timeout for connection establishment (in sec, 0 = System-default)	0
closeOnTimeout	Close the connection and open it again if readTimeout is reached.	on
stripLeading	removes all characters in a received line before a ! or $	off

TcpWriter

A TCPWriter provides NMEA data to other applications.

Parameter	Description	default
port	The port on which the server accepts connections	---
externalAccess	If active, other devices can also connect. Otherwise, only apps on the same device can connect.	off
writeTimeout	Close the connection if an NMEA data set could not be written within the set time (sec).	5
readData	If active, AvNav also receives NMEA data via an established connection	off
stripLeading	removes all characters in a received line before a ! or $ (only if readData is active)	off
sendOwn	Send data received on the same connection (only visible if readData is active). Normally you should not turn this on because it is very easy to create loops.	on
mdnsEnabled	advertise the service in the network via mDNS (type: _nmea-0183._tcp)	off
mdnsService	The name under which this server is accessible via mDNS

UdpReader

A UDP reader receives data from other apps/systems.

Parameter	Description	default
port	the UDP port on which data is received	---
externalAccess	if active, data from other devices can be received, otherwise only within the same device.	off
readTimeout	show the connection as inactive if no data has been received for the set time (sec).	10
stripLeading	removes all characters in a received line before a ! or $	off

Important note: Due to restrictions of the Android system, UDP messages to a broadcast address cannot be received if the device goes into standby mode (screen off). Messages sent directly to the device's IP address continue to be received even in standby. If such broadcast UDP senders are to be used, the device must remain active. You can, however, use the button in AvNav to dim the backlight and reduce power consumption. See also GitHub Issue #510.

UdpWriter

A UDP writer sends NMEA data via UDP to another app.

Parameter	Description	default
ipaddress	the IP address or the hostname of the target computer. An mDNS name like "avnav.local" can also be used.	---
port	The target port to which data should be sent	---
broadcast	Send the data as a broadcast; the IP address must then be a valid broadcast address.	off

NMEA0183Service

An NMEA0183 service works essentially like a TcpReader. However, the target address and port are not specified here. Instead, the name of a (mDNS) service (type: _nmea-0183._tcp) is selected from a list of available services. If, for example, a SignalK server or an AvNav server (> 20210415) is present in the network, they announce their NMEA outputs in the network in this way.
The advantage is that even when changing the network, access will normally work again, and connections can be automatically re-established.

Parameter	Description	default
service	the name of the service (selection from the list of found ones)	---
sendOut	send NMEA data on this connection
readTimeout	Mark the connection as inactive if no data has arrived after the set time (sec).	10
writeTimeout	Close the connection if a sentence could not be written within the set time (sec)	5
connectTimeout	Timeout for connection establishment (in sec, 0 = System-default)	0
closeOnTimeout	Close the connection and open it again if readTimeout is reached.	on

UsbConnection

AvNav becomes active when a USB device is connected if this is activated in the settings. It is therefore useful to start AvNav first and then connect the USB device. The device can then be configured directly so that AvNav is always allowed to access it. AvNav will then immediately start the dialog for configuring the device.

Parameter	Description	default
device	The connected USB device, more precisely: the connection of the device, selection from a list	---
baud rate	The baud rate	9600
flowControl	none	xon/xoff
sendOut	send NMEA data on this connection	off
readTimeout	Mark the connection as inactive if no data has arrived after the set time (sec).	10

Bluetooth

For connecting to, for example, a Bluetooth GPS. The device must first be connected via the Android device's Bluetooth settings ("pairing").

Parameter	Description	default
device	The Bluetooth device. During setup, all devices that are already known are offered; only then is an attempt made to reach the device.	---
sendOut	send NMEA data on this connection	off
readTimeout	Mark the connection as inactive if no data has arrived after the set time (sec).	10