Status messages

Implemented by status & control module

Used for custom telemetry messages generated by the DroneBridge modules or plugins.

Difference to communication messages/protocol:

• Higher update rates (several times/second)

• No guaranteed delivery/No response

• Shorter

Received by status module on ground station via long range link (embedded in raw protocol)

UAV-RC status update message

Sent by control module on AirPi ~5Hz

Description	Values	Details
RSSI RC on UAV	signed little-endian (?)	1 byte
received RC packets/s	unsigned little-endian	1 byte
AirPi CPU usage [%]	unsigned little-endian	1 byte
AirPi CPU temp [°C]	unsigned little-endian	1 byte
AirPi low voltage	unsigned little-endian	1 byte
unused	unsigned little-endian	1 byte

AirPi low voltage = 1 if low.

Messages sent by status module to a ground control station (app)

DroneBridge system-status message

This frame is generated and sent by the status module as a UDP packet to port 1608. It is 20 bytes long and has the following structure:

Description	Values	Details
Identifier	$D	2 bytes
Message ID	1	1 byte
Mode	UTF-8	1 byte
Received RC packets/s	unsigned	1 byte
RSSI drone (RC)	signed	1 byte
RSSI ground station (video)	signed	1 byte
Damaged blocks (video)	unsigned little-endian	4 bytes
Lost packets (video)	unsigned little-endian	4 bytes
Video bit rate Kbit/s	unsigned little-endian	4 bytes
Voltage status	bit 0: GNDPi; bit 1: AirPi	1 byte

Voltage status:

• bit 0: if set GNDPi is on low voltage

• bit 1: if set AirPi is on low voltage

DroneBridge RC-status message

Gets the RC-Channel values from the control module (ground station). The values are in between 1000 and 2000. These are the values right before they get transformed to DroneBridge RC protocol so calibration issues can be detected!

Description	Values	Details
identifier	$D	2 bytes
message id	2	1 byte
ch1	unsigned little-endian	2 bytes
ch2	unsigned little-endian	2 bytes
ch3	unsigned little-endian	2 bytes
ch4	unsigned little-endian	2 bytes
ch5	unsigned little-endian	2 bytes
ch6	unsigned little-endian	2 bytes
ch7	unsigned little-endian	2 bytes
ch8	unsigned little endian	2 bytes
ch9	unsigned little endian	2 bytes
ch10	unsigned little endian	2 bytes
ch11	unsigned little endian	2 bytes
ch12	unsigned little endian	2 bytes
ch13	unsigned little endian	2 bytes
ch14	unsigned little endian	2 bytes

Messages received the by status module coming from a ground control station (app)

DroneBridge RC-overwrite message

Allows to overwrite the channel values sent by DroneBridge RC via the control module. Can be used by head trackers etc.. Not intended to be used for regular control of the UAV. Please modify the implementation of the control module for that purpose.

Description	Values	Details
identifier	$D	2 bytes
message id	3	1 byte
ch1	unsigned little-endian	2 bytes
ch2	unsigned little-endian	2 bytes
ch3	unsigned little-endian	2 bytes
ch4	unsigned little-endian	2 bytes
ch5	unsigned little-endian	2 bytes
ch6	unsigned little-endian	2 bytes
ch7	unsigned little-endian	2 bytes
ch8	unsigned little endian	2 bytes
ch9	unsigned little endian	2 bytes
ch10	unsigned little endian	2 bytes
ch11	unsigned little endian	2 bytes
ch12	unsigned little endian	2 bytes
ch13	unsigned little endian	2 bytes
ch14	unsigned little endian	2 bytes

Channels set to zero will be ignored. Overwrite is only valid for 100ms. To overwrite channels for a longer period of time the update frequency of the RC-overwrite message must be >10Hz. Values must be between 1000-2000.