VBOX Sport Serial (RS232) Protocol

Standard channels examples

1. If only ‘sats’ and ‘speed’ are present the corresponding bit masks 0x00000001 and 0x00000010 would equate to the nnnn field equaling 0x00000011.
2. If ‘sats’, ‘time’, ‘latitude’, ‘longitude’, ‘speed’, ‘heading’, ‘height’, ‘vertical velocity’, ‘lat.acc.’ and ‘long.acc.’ are present then the nnnn field would equal 0x000003FF.

Extended channels examples

1. If only ‘battery time to empty’ is present the iiii field would equal 0x00000001.
2. If ‘battery time to empty’, ‘media capacity’, ‘media free space’ and ‘HDOP’ are all present, the iiii field would equal 0x00000071.

Note: Some bit flags are not used, while others are not available in production units.

Default channels

Fields List

Note that for clarity, the fields are colour coded: 

• The meta-data fields are Green.
• The standard channel fields are Blue.
• The extended channel fields are Purple.
• Any unsupported channels are uncoloured.

 

Code in default message format	Bytes	Description	Bit mask
$VBSPT$	7	Header $VBSPT$
,	1	Comma
nnnn	4	Standard Channel Flags 0x000003FF
iiii	4	Extended Channel Flags 0x00000071
,	1	Comma
s	1	Satellites Bits 0-6 are number of satellites used Bit 7 is set if the VBOX SPORT is using DGPS	0x00000001
ttt	3	Time Number of 10 ms ticks since midnight UTC	0x00000002
aaaa	4	Latitude (minutes * 100,000) Positive = North, Negative = South	0x00000004
oooo	4	Longitude (minutes * 100,000) Positive = West, Negative = East	0x00000008
vv	2	Speed Velocity in knots * 100	0x00000010
hh	2	Heading Degrees from true north * 100	0x00000020
eee	3	Height Altitude in metres WGS84 * 100 True signed 24 bit number	0x00000040
zz	2	Vertical Speed Vertical speed in m/s	0x00000080
xx	2	Long acc (GPS) Longitudinal acceleration in g * 100	0x00000100
yy	2	Lat acc (GPS) Lateral acceleration in g * 100	0x00000200
	4	Brake distance	0x00000400
	4	Distance In m * 128000	0x00000800
	4	Internal analogue 1	0x00001000
	4	Internal analogue 2	0x00002000
	4	Internal analogue 3	0x00004000
	4	Internal analogue 4	0x00008000
	1	Glonass sats	0x00010000
	1	GPS sats	0x00020000
	2	Yaw 0 value	0x00040000
	2	Yaw 0 LatAcc	0x00080000
	2	Yaw 0 Status	0x00100000
	2	Yaw 1 value	0x00200000
	2	Yaw 1 LatAcc	0x00400000
	2	Yaw 1 Status	0x00800000
	4	Velocity quality	0x01000000
	4	Temperature In degrees C * 100	0x02000000
	2	Buffer size	0x04000000
	3	Media Free Space (0xEF7FF – ((percent_free / 100) * 0xEF7FF))	0x08000000
	4	Event time 1	0x10000000
	2	Event time 2	0x20000000
	2	Internal voltage	0x40000000
	2	Battery voltage In mV	0x80000000
bb	2	Battery time to empty In minutes. TTE field from gas gauge. A value of 0xFFFF is shown if the battery is not discharging.	0x00000001
	2	Battery time to full In minutes. TTF field from gas gauge. A value of 0xFFFF is shown if the battery is not charging	0x00000002
	2	Battery charge when full In mAh. FCC field from gas gauge	0x00000004
	2	Battery current charge As a percentage of charge when full. RM field from gas gauge	0x00000008
mmmm	4	Media capacity In kb	0x00000010
ffff	4	Media free space In kb	0x00000020
dd	2	HDOP Value * 100	0x00000040
cc	2	Checksum CRC of message, See Note 1*

 

*Note 1

CRC Calculation example:

s[n] is a string containing the message

Polynomial:= 4129 (0x1021)

CRC:=0;

for Loop:=1 to Length(s) do

begin

Temp:=s[Loop];

CRC:= CRC xor (integer(Temp) * 256);

CRC:= CRC mod 65536;

for i:=7 downto 0 do

begin

if ( (CRC and 32768)=32768) then

begin

CRC:= CRC *2 ;

CRC:= CRC xor Polynomial;

end

else

begin

CRC:= CRC *2 ;

end;

CRC:=CRC mod 65536;

end;

end;

result:=CRC;

Troubleshooting

"I am only receiving a message containing '$VBSPT' from the VBOX Sport"

Please interpret the data as binary to resolve this issue. “$VBSPT” is a header and is in ASCII whilst the rest of the data is binary. Please see the section entitled: ‘Default message format’ at the top of this document for further information.