Advanced
Serial Protocol
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Flags
16-bit Integer
Flag value
Desription
0, 1
Startup Gyro Calibration in progress
2
Startup Gyro Calibration complete
Integration Control Command
The Integration Control Command is sent in order to cause certain values being integrated on the navX-
sensor to be reset to 0.
Byte Offset
Element
Data Type
0
Action
Uint8
(
1
Parameter
Uint32
Integration Control Response
The Integration Control Response is sent in response to an Integration Control Command, confiming that
certain values being integrated on the navX-sensor have been reset to 0.
Byte Offset
Element
Data Type
0
Action
Uint8
(
1
Parameter
Uint32
Register Protocol
In addition to the streaming Serial protocol, navX-sensors may be accessed over the I2C and SPI buses,
using a register-based protocol. This page documents the register-based protocol used on both the I2C and
SPI bus.
Register-based protocol overview
Unlike the streaming Serial protocol, which periodically sends out updates messages whenever new data
is available, the register based protocol is a “polled” interface, in that the consumer of the navX-sensor
data (in this case referred to as a “bus master”) can request data from the navX-sensor at any time. At the
same time, when using the register-based protocol the bus master does not know when new data is
available.
To help this situation, a timestamp – which is updated whenever new data is available – is made
available. Therefore, the general approach to ensure each new data sample is retrieved is to regularly (at
the current navX-sensor update rate) retrieve both the timestamp and the data of interest), and if the
timestamp differs from the previous timestamp by the update rate as expressed in milliseconds, then the
data sample just retrieved is current, and no data has been missed.
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