The CalibrateDownPosition command is used to calibrate the fusion engine with the current down position. In order to map Neblina's XYZ frame of reference to a new frame of X'Y'Z', it is recommended that the user issues the CalibrateForwardPosition command first in the horizontal plane of X'Y'Z' and then we issue this command, while the device is placed downwards aligned with the Z' axis. It is notable that the CalibrateForwardPosition and the CalibrateDownPosition commands do not affect the raw sensor data readings from the Sensor subsystem, and it only affects the Fusion subsystem. The device has to be stationary when this command is issued, otherwise, the command will be rejected by Neblina, and an error packet will be responded to the host.


This command uses the Command-Ack protocol.


Byte Name C Type Value
0 Control Byte ( Packet Type (7:5) / SubSystem (4:0) ) uint8_t 0x41 ( 0b010 / 0b00001 )
1 Payload Length uint8_t 0
2 CRC uint8_t Calculated
3 Command uint8_t 0x1B


This command contains no payload.