Data Sheet

UM7 DATASHEET
Rev. 1.6 – Released 1/10/2016
25
The NMEA sensor packet contains gyro, accelerometer, and magnetometer data measured by
the sensor. Because all the needed data will not fit into a single packet, this packet will be
transmitted three times, once for each sensor.
PACKET FORMAT
$PCHRS,count,time,sensor_x,sensor_y,sensor_z,*checksum
e.g. $PCHRS,1,105.015,-0.9987,-0.9987,-0.9987,*79
PACKET FIELD DESCRIPTION
Field
Description
$PCHRS
Header field, always precedes the attitude packet
count
e.g. 1
This flag can be 0, 1, or 2. If 0, then the packet contains gyro data. If 1, then
the packet contains accelerometer data. If 3, then the packet contains
magnetometer data.
time
e.g. 105.015
This field can be up to 13 digits long. There will always be 3 decimal digits.
If no GPS is connected, this represents the amount of time in seconds since the
sensor was last turned on. If GPS with PPS is properly connected, this is
synchronized to UTC time of day.
sensor_x
e.g. -0.9987
This field can be up to 11 digits long. On accel and mag data, there will always
be 4 decimal digits. On gyro data, there will always be 2 decimal digits.
This represents sensor data as specified in the ‘count’ field above. Gyro data is
in degrees per second. Accelerometer data is in gravities. Magnetometer data
is unit-norm (unitless).
sensor_x
e.g. -0.9987
This field can be up to 11 digits long. On accel and mag data, there will always
be 4 decimal digits. On gyro data, there will always be 2 decimal digits.
This represents sensor data as specified in the ‘count’ field above. Gyro data is
in degrees per second. Accelerometer data is in gravities. Magnetometer data
is unit-norm (unitless).
sensor_x
e.g. -0.9987
This field can be up to 11 digits long. On accel and mag data, there will always
be 4 decimal digits. On gyro data, there will always be 2 decimal digits.