Instructions

6 Reading digital output data
The sensor generates fully calibrated and temperature compensated digital pressure values
which is available for the user to read through host controller. Sensor must be interfaced
to the host controller via I
2
C interface. For details about I
2
C interface, refer to chapter 4 .
Once the host controller (master) sends the start condition and data direction bit as READ
(R/W=1), the sensor starts transmitting the pressure (2 bytes) and temperature (2 bytes)
data. Pressure data is transmitted in 1
st
and 2
nd
bytes as a 15 bit information. Temperature
data is then transmitted in the following two bytes (3rd and 4th) as a 15 bit information. New
Pressure and temperature data is generated every 2.2 ms. The sensor will continue to send
the alternating pressure and temperature values as 15-bit information until it is deactivated
by a STOP condition from the host controller.
Figure 9 shows the reading operation the master and the slave device (sensor).
S
Slave address
+ Read
ACK Data Data NACKACK
Transmission from master to slave
Transmission from slave to master
S
P
ACK
NACK
START condition
STOP condition
Acknowledge
No acknowledge
Host controller reading multiple data bytes from the sensor (slave)
PDataACK DataACK
P
H
P
L
T
H
T
L
P
H
Pressure high byte (MSB)
P
L
Pressure low byte (LSB)
T
H
Temperature high byte (MSB)
T
L
Temperature low byte (LSB)
1
st
2
nd
3
rd
4
th
Figure 9: Reading output data with I
2
C interface
The sensor response time is about 2.2 ms, meaning it sends a new set of
pressure (2 bytes) and temperature (2 bytes) data every 2.2 ms. With the I
2
C
clock frequency of 400 kHz, the exchange of the 4 data bytes containing the
current pressure and temperature values takes about 80 µs.
Differential Pressure Sensor, Part Nr. 25131308xxx01
User manual version 1.0 © August 2019
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