DEMOAPEXSENSOR Freescale Semiconductor, DEMOAPEXSENSOR Datasheet - Page 9

• Manufacturer Part Number: DEMOAPEXSENSOR
• Description: BOARD DESIGN ALTITUDE PRESSURE
• Manufacturer: Freescale Semiconductor

Specifications of DEMOAPEXSENSOR

• Sensor Type: Accelerometer, Pressure, Water Level, Altimeter/Barometer
• Sensing Range: Multiple Ranges
• Interface: I²C, SPI, Analog
• Sensitivity: Multiple
• Voltage - Supply: 10 V
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: MPX2102, MPXV5004G, MPL115A2, MMA7361L
• Acceleration: 6 g
• Sensing Axis: Triple Axis
• Output Type: Digital
• Interface Type: I2C, SPI
• Operating Voltage: 16 V
• Operating Current: 10 mA
• Leaded Process Compatible: Yes
• Peak Reflow Compatible (260 C): Yes
• Rohs Compliant: Yes
• Silicon Manufacturer: Freescale
• Silicon Core Number: MPXM2102A, MPXV5004G, MPL115A2, MMA7361L
• Kit Application Type: Sensing - Sampling Kit / Related Components
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: MPL115A, MPXM102A, MPXV5004G

Altimetry
Barometer Compensated Pressure Output
Sensors
Freescale Semiconductor
1. Alti/Baro
2. Waterlevel
3. Inertial
4. Additional
1. Altimetry
a. MPXM2102A
b. MPL115A2
c. Experimental
UPorDN
Press
UPorDN
Press
‘b’
ENT
ENT
‘1’
1. Altimetry
a. MPXM2102A
b. MPL115A2
c. Experimental
Select the MPXM2102A,
option ‘a’ for higher resolution,
amplified pressure readings
for Altimetry.
MPL115A2
Press ADC
Temp ADC
ENTER for Coefficients
The values for the MPL115A
are shown here. To the left are
the Pressure and Temp ADC
values in their raw form in
HEX. To the right of them are
the shifted values displayed in
decimal.
Raw Values
74c0
6b40
Press
UPorDN
0467
0428
ENT
ENT
‘a’
Raw Value
0x017c1d
2(LP) value
0x017c1f
Note the way that the output is displayed. The Raw value of the
24-bit ADC value is displayed on the left. The bottom left has the
raw value after it passes two low pass filters in software. This value
is mores stable but takes longer to update.
On the right the Altitude is displayed. This is the pressure
converted to altitude in (m). The Pressure corresponding to the
ADC value is shown in the bottom right.
The board can be placed on the table. Note the Altitude
measurement as it stabilizes. Then raise it above your head as a
‘1m’ increase. The value should go up by 1m. Place on the table
again. It should drop to the original value. Place on the floor, it will
again decrement 1m. Note that ambient pressure from A/C units
can affect this value drastically.
6 Coefficients
ao = 3dc4
b1 = bd7a
b2 = c299
Values of the Coefficients are
shown here. These are used
for the next step in calculating
the compensated Pressure.
ALARM System
Enter your Threshold
Enter for Activation
Continued from the MPL115A
compensated Barometer
section above. Press UP and
DN to set the Alarm Threshold
in increments of 0.25kPa.
Press ENT to activate the
Alarm
0.50
c11 = f8a0
c12 = 2flc
c22 = 0dc0
95.365
Altitude
Pressure
459m
ENT
ENT
kPa
kPa
Compensated Pressure
PComp
Altitude = 365 m
Compensated Pressure is
displayed. This is with an
accuracy of ±1kPa.
Press ENT to continue to the
Alarm section.
ALARM sounds when
Threshold is reached
Press.
ALARM
Alarm is now Active. Note the
outputs of the current Pressure
in kPa, and the Alarm
Threshold point. Once
crossed, the red LED will flash
as the buzzer sounds. Try
activating by pressurizing the
MPL115A. This can be done
with a plastic syringe with
rubber tubing at the end to
make an air tight fit.
=9778
96.574
97.324
kPa
AN3956
ENT
kPa
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