OpenCPN

Simple gauge instrument

Simple gauge instrument

A circular instrument displaying a single numerical value. Allows to select formatting and unit conversion from the SI units used by Signal K to usual units used in navigation. Multiple visual styles are available to cover absolute and relative directions, scalar values and proportions/percentages.

Table 2. Configuration parameters
Parameter Description Example

Name

Name of the instrument

Time from primary GPS

Title

Title of the instrument to be displayed

GPS Time

Timeout

Timeout in seconds. If the set numeber of seconds passes since the last update for the Signal K key displayed by the instrument pass without receiving an update, the value is considerd timed out and is replaced by dashes.

3

SK key

Fully qualified Signal K path to the value displayed by the instrument

vessels.urn:mrn:signalk:uuid:76bb2350-c92e-4e47-b3c3-e12273f21155.environment.depth.belowTransducer

Gauge type

Type of the gauge

Table 1. Gauge types

Relative angle

Displays angles relative to the boat (-180-180 degrees), eg. apparent or true wind. The RAD → DEG transformation has to be used to convert the Signal K data from Radians to degrees.

Direction

Displays angle (0-360 degrees), eg. COG, heading or true wind direction. The RAD → DEG transformation has to be used to convert the Signal K data from Radians to degrees.

Percentile

Percent value (0-100%). The ratio → % transformation has to be used to convert the Signal K data to percent.

Adaptive range indicator

Arbitrary numerical value with adaptive range. The instrument scale is dynamically updated based on the received data.

Fixed range indicator

Arbitrary numerical value with fixed range. The instrument scale is static and set based on the minimal and maximal value set for the Zones. In case the actual value is out of the range, the needle is not displayed (but the numerical value in the center of the gauge is.)

Format

Format of the displayed number.

Supported formats

  • 9.9

  • 9.99

  • 9.999

  • 9

  • 009

  • 009.9

  • 09.9

  • 09.99

  • 009.99 If displaying a sign in front of the number for negative values is undesirable, select the format marked by ABS, eg. ABS(009).

Transformation

Function to be used to convert the value from the SI unit used by Signal K to human readable form

Supported transformation functions

  • None

  • RAD→DEG

  • m/s → kn

  • m/s → km/h

  • m/s → mph

  • m → feet

  • m → fathoms

  • m → NMi

  • Kelvin → Celsius

  • Kelvin → Fahrenheit

  • ratio → percent

  • Pa → hPa

  • Pa → kPa

  • Pa → MPa

  • Pa → atm

  • Pa → mmHg

  • Pa → psi

  • Hz → RPM

  • RAD/s → Degrees/min

Zones

Value zones used to trigger visual alarm (Changing the colors of the instrument if the displayed value is within a zone). Refer to the detailed documentation.

Data smoothing

Degree of data smoothing. The value between 0 and 9 configuring how smooth the transition between values received from the data stream should be.

O means no smoothing, the latest value received from the data stream is directly displayed.

Values between 1 and 9 regulate how aggressive the smoothing algorithm is.

1 means the latest received value has 90% influence on what is displayed, 10% the earlier values. Lower values are suitable for data possibly changing fast in real world and the sensors with steady output, like depth.

9 means the latest received value has only 10% influence on the displayed value and 90% the earlier values. This makes the transition between values very smooth, not fluctuating wildly, but means a signifiant delay in reaching close to the actual value received from the sensor. Higher values are suitable for data not changing fast in real world and coming from sensors suffering big fluctuation coming from boat movement and other factors, for example wind strength and direction.

1

Instrument size

Diameter of the instrument on screen

100

Title size

Font size of the instrument Title

10

Needle color

Color of the instrument needle

Rim color

Color of the rim of the instrument

Port color

Color of the port part of the rim for realtive angle gauge type

Starboard color

Color of the starboard part of the rim for realtive angle gauge type

Dead angle

Color of the dead angle (unsailable) part of the rim for realtive angle gauge type

Dial color

Fill color of the gauge dial

Title color

Color of the title text

Value color

Color of the displayed numerical value

Tick color

Color of the tick lines

Dial values

Color of the numerical scale values displayed next to the tick lines

Normal color

Text color of the value part of the instrument when the value is within an alert zone

Alert color

Text color of the value part of the instrument when the value is within an alert zone

Warning color

Text color of the value part of the instrument when the value is within a warning zone

Alarm color

Text color of the value part of the instrument when the value is within an alarm zone

Emergency color

Text color of the value part of the instrument when the value is within an emergency zone

Border color

Color of the border of the instrument