HP203B Datasheet, PDF (6/18 Pages) List of Unclassifed Manufacturers – PRECISION BAROMETER AND ALTIMETER SENSOR

DataSheet
HP203B
4.2.1 Soft Reset the Device
.SOFT_RST (0x06)
Once the user issues this command, the device will immediately be reset no matter what it is
working on. Once the command is received and executed, all the memories (except the NVM) will
be reset to their default values following by a complete power-up sequence to be automatically
performed.
4. 2.2 OSR and Channel Setting
.ADC_CVT (010, 3-bit OSR, 2-bit CHNL)
This command let the device to convert the sensor output to the digital values with or without
compensation depends on the PARA register setting. The 2-bit channel (CHNL) parameter tells the
device the data from which channel(s) shall be converted by the internal ADC. The options are shown
below:
00: sensor pressure and temperature channel
10: temperature channel
The 3-bit OSR defines the decimation rate of the internal digital filter as shown below:
000:
OSR = 4096
011: OSR = 512
001:
OSR = 2048
100: OSR = 256
010:
OSR = 1024
101: OSR = 128
Setting the CHNL bits to the value of 01 or 11, or the OSR bits to the values of 110 or 111 will lead
to failure of conversion.
4. 2.3 Read the Temperature and Pressure Values
READ_PT (0x10)
The temperature data is arranged as 20-bit 2’s complement format and the unit is in degrees
C.Temperature value is stored in all 24 bits of OUT_T_MSB, OUT_T_CSB and OUT_T_LSB. The 4
most significant bits of the 24-bit data is useless, while the 20 least significant bits represent the
temperature value. The user shall convert this 20-bit 2’s complement binary value into an integer, and
then divide the integer by 100 to obtain the final result.
The pressure data is arranged as 20-bit 2’s complement format and the unit is in Pascal. Pressure
value is stored in all 24 bits of OUT_T_MSB, OUT_T_CSB and OUT_T_LSB. The 4 most significant
bits of the 24-bit data is useless, while the 20 least significant bits represent the pressure value. The
user shall convert this 20-bit unsigned binary value into an integer, and then divide the integer by 100
to obtain the final result.
For Example :(Temperature)
Hex v alue
OUT_T_MSB
0x000A5C
0x00
0xFFFC02
0xFF
OUT_T_CSB
0x0A
0xFC
OUT_T_LSB
0x5C
0x02
Dec v alue
26.52
-10.22
For Example :(Unsigned data pressure)
Hex v alue
OUT_ P _MSB
0x018A9E
0x01
OUT_ P_CSB
0x8A
OUT_ P_LSB
0x9E
Dec v alue
1010.22
4. 2.4 Read the Temperature and Altitude Values
.READ_AT (0x11)
The temperature data is arranged as 20-bit 2’s complement format and the unit is in degrees
C.Temperature value is stored in all 24 bits of OUT_T_MSB, OUT_T_CSB and OUT_T_LSB. The 4
most significant bits of the 24-bit data is useless, while the 20 least significant bits represent the
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