tutorials

Parts / Assembly - Black Box

This tutorial covers everything you’ll need to know about your Black Box data recorder. The Black Box will record everything you might want to know about your flight from pressure and temperature to position and altitude.

First up we’ll need to charge the unit

You can charge the unit using the mini USB port. This is for charging only, not for data transfer.

ChargingThe battery LED will either be red, amber or green based on its charge. You can find a detailed status sheet for the LED indicators here:

Black Box Folder

Next, insert a microSD card into the slot

Micro SD card

The holder is located quite far into the slot so you’ll need to push the card in with a small tip (like a small screwdriver). Make sure that it clicks into place.

Connect the external sensors

External Sensors

To turn on the Black Box

Push the yellow button on top. The unit will automatically start up and begin looking for satellites.

Turning on

The data LED will shine amber whilst the unit is powering up. Once it has started to record data, it will shine green.

Recording data

Once you’ve finished recording, press and hold the yellow button for 5 seconds.

The lights will flash for one final time and then the unit can be switched off at the side (by pushing the slider switch away from the wire).

The black box data

The data comes off the card in 4 different file types. Acceler, Atmos, Magnetom, Position. Each file number is continuous from the last (split up so that if the worst happens and you land in water corrupting the electronics or something similar, you’ll only ever lose the final data file).

The data from each file is as follows:

Acceler

Timestamp, X acceleration, Y acceleration, Z acceleration, board heaters on/off
The accelerations (as with any other directional data) align with the box as shown below:

Acceler

Board heaters are used to maintain the temperature of the circuits. We’ve included a check to see whether they were on (1) or off (0).

Atmos

The atmospheric data files contain; timestamp, circuit temperature (C), external temperature (C), pressure (mbar) and humidity.

Magnetom

The magnetometry data files contain; timestamp, X magnetometry, Y magnetometry, Z magnetometry, battery voltage.

Position

Position data files are in the form of two sentences of NMEA data. Simply put, this means that there are two lines of GPS data for each time stamp. These are $GPRMC and $GPGGA.

$GPRMC includes:

Time Stamp
validity (A-ok, V-invalid)
current Latitude (North/South)
current Longitude (East/West)
Speed in knots
True course
Date Stamp
Variation
East/West
checksum

$GPGGA includes

Time
Latitude (North/South)
Longitude (East/West)
Fix quality (0 = invalid, 1 = GPS fix, 2 = DGPS fix)
Number of satellites in view
Horizontal Dilution of Precision (HDOP) – the relative accuracy of horizontal position
Altitude (m)
Height of geoid above WGS84 ellipsoid (m)
Time since last DGPS updateGPS reference station id
Checksum

Looking at the data

You can download our black box data tool here. Simply download the files from your SD card to a computer, then run the data tool. Click the ‘choose data folder’ button and navigate to the folder containing the files. Click ‘process my data!’ and the tool will collate each of the files into a complete excel spreadsheet for easy viewing and prcoessing, as well as giving you some vital statistics from your flight.

This tool is in development and will be updated periodicaly to add more features. If there’s something you’d like to see, drop us an email and let us know!

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