Datasheet

ICP-10111
Document Number: DS-000177 Page 16 of 31
Revision: 1.3
PROPERTY
VALUE
Name
CRC-8
Width
8 bits
Polynomial
0x31 (x
8
+ x
5
+ x
4
+ 1)
Initialization
0xFF
Reflect input
false
Reflect output
false
Final XOR
0x00
Examples
CRC(0x00) = 0xAC
CRC(0xBEEF) = 0x92
Table 16. ICP-10111 I
2
C CRC Properties
5.9 CONVERSION OF SIGNAL OUTPUT
Pressure measurement data is always transferred as 4 8-bit words; temperature measurement data is always transferred as two 8-
bit words. Please see section 5.5 for more details.
Temperature measurement values t_dout are linearized by the ICP-10111 and must be calculated to °C by the user via the following
formula:
T = - 45°C +
175°C
2
16
× t_dout.
For retrieving physical pressure values in Pa the following conversion formula has to be used:
P = A +
B
C + p
dout
,
where p_dout is the sensor’s raw pressure output. The converted output is compensated for temperature effects via the
temperature dependent functions A, B and C. Besides the raw temperature output t_dout, the calculation of A, B and C requires to
access calibration parameters OTP0, OTP1, OTP2, OTP3 stored in the OTP of the sensor. Read-out of OTP parameters is described in
section 5.10.
Full sample code for calculating physical pressure values is given in section 5.11. The general workflow of the conversion is done by:
1) Import class Invensense_pressure_conversion
2) Read out values OTP0, …, OTP3 and save to c1, …, c4
3) Create object name for an individual sensor with parameter values c1, …, c4
name = Invensense_pressure_conversion
([c1,c2,c3,c4])
4) Get raw pressure p_dout and temperature t_dout data from the sensor as described in chapter 5.5.
5) Call function get_pressure:
name.get_pressure(p_dout, t_dout)
The sample code from section 5.13 gives an example of this workflow.