Cumulus

Current Hardware

What current hardware is available to run Cumulus?

Current hardware devices for Cumulus are the Nokia Internet Tablets N800 and N810 with OS2008 since 2008 and the N900 with OS2009 since 2010. Cumulus can be installed with the tablet package manager on these devices without flashing the Maemo OS against another one.

You do need a GPS unit to take full advange of Cumulus. This can be an internal or external GPS receiver. The Nokia Internet Tablet N810/N900 has already included a GPS receiver but the tablet can also be connected via USB or Bluetooth to an external GPS device.

Nokia N810 core features

The Nokia internet tablet N810 is the preferred device for Cumulus at the moment and has the following core features:

GPS devices

All GPS devices that provide a standard NMEA formatted data stream via a serial, USB or a bluetooth connection should be useable with Cumulus.

FAI loggers and advanced instruments

Most FAI loggers and advanced instruments like FLARM can be used with Cumulus as they output a NMEA formatted data stream just like a normal GPS does. Often these devices have only a RS232 interface whilst the Internet Tablet has an micro USB port. To connect both together you need a USB-RS232 gadget. A adapter with a Prolific PL2303 chip should work as stated in the tablet forum. For the connection you need a female A to male micro-A adapter. Furthermore you have to install the kernel modules pl2303.ko and usbserial.ko. They are needed to connect any gadget through USB with a cable USB to Serial.

Cumulus can take advantage of the additional information these devices supply beside the normal GPS data. The manufacturers often use proprietary NMEA sentences, not standard conform, to code such data in special messages. At the moment Cumulus can process and use the proprietary data sentences (pressure Altitude, STD Altitude, QNH, Wind, Variometer) of a Cambridge, LX, Volkslogger and FLARM device.

Confirmed to work with Cumulus are:

Other hardware?

If you have successfully ran Cumulus on other hardware than listed here, please let us know!

If you have knowleage about devices which provide additional information like Variometer, Wind, Presseure related Altitudes, ... and Cumulus should integrate them, please contact us. A format description and a ascii trace would be a good help for us.

Altitude errors & correction

Not all GPS devices use geoid correction. That is, they do not provide an MSL altitude when they should, but an altitude above an elipsiod that is an approximation to the real curvature of the earth. This introduces errors, that will show up as a relatively fixed error in the altitude Cumulus will return. Some devices do have this information, but don't take it into account when returning altitudes. See if the error goes away if you choose "HAE" (Heigt Above Elipsoid) instead of "MSL" (Mean Sea Level) for the altitude mode on the GPS tab of the settings dialog.

If this doesn't work, your device does not supply any correction information. If you have such a device, you can use this website to calculate the error for your region. Then, in settings dialog on the GPS page, choose the "user" setting for altitude and input the error calculated above as the "Altitude Correction". Cumulus should now report the correct altitude. Note that this error is dependent on your location, so don't assume it is accurate if you travel far away from the location the error was calculated for.

Note that making sure the altitudes are approximatly correct is important. If the altitudes are off, the arrival altitudes and thus the airfields in reach are not accurate for use!