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Flarm

Cumulus can be connected with a Flarm device and is able to process the the proprietary sentences emitted by that device. It displays the most important and one selected object at the map. Furthermore a radar view display is provided with all received Flarm contacts.

Warning

Please note, that Cumulus does not warn you of dangerous objects as Flarm it does. Cumulus is not a replacement of Flarm, it is only an addition to it!

Flarm connection

Flarm devices have only a bidirectional serial RS232 interface. Cumulus can be connected with a Flarm device via this interface or by means of a RS232-USB gadget. That all depends on the available hardware of your PDA. The use of an USB connection requires that the USB port supports the OTG (On-the-go) mode. That is ensured for the Nokia Internet Tablets N8x0 but not for the N900 model.

Flarm configuration

To get the specific Flarm data, you have to enable the NMEAOUT option in the FLARM setup menu. Activate the sending of GPRMC, GPGGA, GPPSA, PGRMZ plus FLARM proprietary sentences. As transfer speed you should select 57.6 kBaud. Cumulus sends no initialization data to Flarm. Therefore you must setup the Flarm device by using an initialization file flarmcfg.txt, contained on a micro SD card and put into your Flarm device before power on or by using the Flarm Tool on a PC. See FLARM DATA PORT SPECIFICATIONS for more information, to find at www.flarm.org.

Cumulus GPS settings

Select in the Settings/GPS menu a serial, bluetooth or USB device according to your available hardware and set the transfer speed to 57600. Futhermore use as Altitude Reference the entry Pressure. That ensures, that the data of the pressure sensor are taken as altitude. Calibrate the delivered altitude to the expected altitude by using the altitude dialog. It can be opened by tipping on the altitude display in the map view.

Flarm radar view

You can open the Flarm radar view by tipping on the Track (Trk) display in the map view. The view consist of an inner and outer circle and a cross in the center. The upper end of the vertical line points to 12 o'clock. In the left upper corner you can see the current selected display scale and at the right side of the window you have the following buttons for operation from top down:

Scale: Pressing the zoom button toggles between three different scales (0.5, 1.0, 6.0 Km), displayed in the left upper corner.
List: Pressing the list button opens a new window with a list overview about all just received Flarm contacts.
Time: Pressing the time button toggles the refresh of the radar view between 1, 2 and 3 seconds. Default is 2 seconds. The refresh rate has also influence on the processor load and the object selection.
Aliases: Pressing the monkey button opens a new window with a table overview about your defined Flarm alias names.
Close: Pressing the close button returns to the map view.
Flarm objects are displayed at the radar view in different shapes according to their delivered information.

Square: If no track information is available the Flarm object is drawn as square.
Arrowhead: If track information is available the Flarm object is drawn as arrowhead, where the tip points into the move direction.
Objects are drawn in different colors according to their assigned alarm level and depending on their selection. The used colors are:

Black: The alarm level of the object is no.
Orange: The alarm level of the object is important.
Red: The alarm level of the object is urgent.
Magenta: The object has been selected by the user. In this case the alarm level of the object is not considered.
If you tip on a Flarm object in the radar view, you can get displayed additional information, if they are available. All information are drawn in the color magenta. These are:

Flarm identifier: The identifier of the selected Flarm object is displayed in the lower left corner as 6-digit hex value. If an alias name has been defined for the Flarm identifier, that name is taken in place of.
Distance: The distance to the selected Flarm object is displayed in the lower right corner of the window.
Vertical separation and climb rate: The vertical separation to and the climb rate of the selected Flarm object are displayed in the upper right corner of the window.

Flarm list view

Pressing the list button in the radar view opens a new window with a list overview about all just received Flarm contacts. The following information can be displayed:

Flarm identifier: The identifier of the Flarm object as 6-digit hex value. If an alias name has been defined for the Flarm identifier, that name is taken in place of.
Distance: The distance to the Flarm object from the own position.
Vertical separation: The vertical separation to the Flarm object above or below the own position. Can be positive or negative.
Relative bearing: The relative bearing to the Flarm object as arrowhead.
Ground speed: The ground speed of the Flarm object.
Rate of climb: The rate of climb of the Flarm object. Can be positive or negative.
A certain entry in the list can be selected by tipping on it. If you press then the Select button, the window is closed and you will return to the radar view. The additional data of your selected entry are displayed now here. A made selection can be reset by pressing the Unselect button followed by the Close button.

Flarm alias list

Pressing the monkey button opens a new window with a table overview about your defined Flarm alias names. An 6-digit Flarm hex identifier can be replaced by a more speaking name. The length of an alias name is limited to 15 characters. To add a new alias name, press the Plus button. That appends a new row with two columns at the end of the table. Enter in the left column the Flarm identifier to be translated and in the right column your desired alias name. An existing entry can be changed by clicking on the cell to be modified. Note! If you add several times the same Flarm identifier in the table, only the last entry is saved. If you want to remove one or more entries, select them and press the Trash button.

Leave the window with the Ok button to store your made changes or with the Cancel button to discard all.

You have the possibility to select one row in the table and to leave the window with the Ok button. The selected Flarm object will become your new selection in the radar view. To make a deselection of a selected object in the radar view, go into the alias window, do nothing select and return via Ok to the radar view.

Flarm alias file

The content of the Flarm alias table is stored in a file with the name cumulus-flarm.txt. The file name is hard coded and the file is stored in the user's Data Directory.

The file format of the Flarm alias list is very simple. A comment line starts with a hash mark or a dollar sign at the most left position and ends with the new line sign. A valid entry has the following format:

<Flarm-Id> '=' <Alias-Name>

Example:

# Flarm alias file, comment line
$ another comment line
ABCDEF=My best friend
Note, that white spaces are not allowed on both sides of the equal sign!

Flarm data up-to-dateness

Flarm data olden very fast, especially if the objects do circle. Flarm normally sends every second data about the objects in view. But if a Flarm contact leaves the receiver range, never new data about it will arrive Cumulus. To clean the collected data, all Flarm contacts are removed regularly, which were not updated within three seconds.

The data in the Flarm list view are updated only every three seconds to reduce the processor load.

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