your position is our focus
5.4 Testing of LEA-4R/TIM-4R Designs
The
GPS
functionality
should
be
checked
as
outlined
in
Section 5.3
.
!
Note
When
testing
the
design
ensure
that
no
GPS
signals
are
being
received.
Failure
to
do
so
can
eventually
result
in
operation
errors.
5.4.1 Direction
Signal
This
input
shall
be
set
once
to
high
level
and
once
to
low
level.
In
both
states
the
software
parameters
are
read
back
with
the
UBX-NAV-EKFSTATUS.
The
direction
flag
shall
read
FWD_HIGH
=
1
(forward)
for
a
high
level
at
the
FWD
input
and
FWD_LOW
=
-1
(backward)
for
a
low
level
at
the
FORWARD
input.
5.4.2 Speedpulse
Signal
A
rectangular
waveform
with
2kHz
frequency
shall
be
fed
into
the
SPEED
input.
The
result
can
be
read
back
with
the
UBX-NAV-EKFSTATUS
message.
The
number
of
speed
pulses
during
the
last
update
period
divided
by
the
duration
of
the
last
update
period
shall
correspond
to
the
input
signal
frequency.
Period
s
Speedpulse
f
in
=
5.4.3 Gyroscope
(Rate)
Input
Three
different
DC
voltages
1.0
V,
2.5
V
and
4.0
V
shall
be
applied
to
the
rate
input
(input
of
the
A/D
converter)
and
the
measurements
will
be
read
out
with
the
UBX-NAV-EKFSTATUS
message.
The
voltage
applied
to
the
rate
input
can
be
measured
using
the
‘mean
gyro’
value
from
the
UBX-NAV-EKFSTATUS
message
multiplied
with
5
V/(2
16
-1)
=
76.2951e
-6
V
or
read
directly
from
the
message
output.
76.2956µV
*
mean_gyro
V
gyro
=
!
Note
The
rate
input
can
only
be
tested
if
an
A/D
converter
is
connected
to
LEA-4R/TIM-4R.
5.4.4 Temperature
Sensor
The
temperature
measured
by
the
temperature
sensor
connected
to
the
LEA-4R/TIM-4R
shall
be
read
with
the
UBX-NAV-EKFSTATUS
message.
The
measurement
tolerance
is
in
the
order
of
about
±5°.
5.4.5 Erase
Calibration
To
erase
the
calibration
send
a
CFG-EKF
command.
LEA-4R
/
TIM-4R
-
System
Integration
Manual
/
Reference
Design
Product
Testing
GPS.G4-MS4-05043
Page 34
