BMP180 Bosch Sensortec, BMP180 Datasheet - Page 15

• Manufacturer Part Number: BMP180
• Description: Specifications: Lead Free Status: Lead Free ; RoHS Status: RoHS Compliant
• Manufacturer: Bosch Sensortec

BST-BMP180-DS000-07 | Revision 2.3 | May 2011
© Bosch Sensortec GmbH reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such as copying and passing on to third
UT = MSB << 8 + LSB
UP = (MSB<<16 + LSB<<8 + XLSB) >> (8-oss)
X1 = (UT - AC6) * AC5 / 2
X2 = MC * 2
B5 = X1 + X2
T = (B5 + 8) / 2
B6 = B5 - 4000
X1 = (B2 * (B6 * B6 / 2
X2 = AC2 * B6 / 2
X3 = X1 + X2
B3 = ((AC1*4+X3) << oss + 2) / 4
X1 = AC3 * B6 / 2
X2 = (B1 * (B6 * B6 / 2
X3 = ((X1 + X2) + 2) / 2
B4 = AC4 * (unsigend long)(X3 + 32768) / 2
B7 = ((unsigned long)UP - B3) * (50000 >> oss)
if (B7 < 0x80000000) { p = (B7 * 2) / B4 }
X1 = (p / 2
X1 = (X1 * 3038) / 2
X2 = (-7357 * p) / 2
p = p + (X1 + X2 + 3791) / 2
else { p = (B7 / B4) * 2 }
parties. BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.
Note: Specifications within this document are subject to change without notice.
read reg 0xF6 (MSB), 0xF7 (LSB), 0xF8 (XLSB)
read out E
read uncompensated temperature value
display temperature and pressure value
write 0x34+(oss<<6) into reg 0xF4, wait
read uncompensated pressure value
write 0x2E into reg 0xF4, wait 4.5ms
read reg 0xF6 (MSB), 0xF7 (LSB)
from the E
8
) * (p / 2
11
Calculation of pressure and temperature for BMP180
calculate true temperature
2
/ (X1 + MD)
calculate true pressure
PROM registers, 16 bit, MSB first
Read calibration data
4
AC1 (0xAA, 0xAB)
AC2 (0xAC, 0xAD)
AC3 (0xAE, 0xAF)
AC4 (0xB0, 0xB1)
AC5 (0xB2, 0xB3)
AC6 (0xB4, 0xB5)
MC (0xBC, 0xBD)
11
13
MD (0xBE, 0xBF)
MB (0xBa, 0xBB)
B1 (0xB6, 0xB7)
B2 (0xB8, 0xB9)
16
8
2
16
PROM of the BMP180
)
Start
12
12
2
)) / 2
)) / 2
15
4
Figure 4: Algorithm for pressure and temperature measurement
16
11
15
(16 bit)
(16 bit)
(16 bit)
(16 bit)
(16 bit)
(16 bit)
(16 bit)
(16 bit)
(16 bit)
(16 bit)
(16 bit)
Data sheet
BMP180
example:
AC1 =
AC2 =
AC3 =
AC4 =
AC5 =
AC6 =
B1 =
B2 =
MB =
MC =
MD =
UT =
oss =
= oversampling_setting
(ultra low power mode)
UP =
X1 =
X2 =
B5 =
T =
B6 =
X1 =
X2 =
X3 =
B3 =
X1 =
X2 =
X3 =
B4 =
B7 =
p =
X1 =
X1 =
X2 =
p =
1171050000
-32767
-14383
27898
23843
32741
32757
23153
33457
70003
74774
69965
-2344
-1601
-7859
-8711
6190
2868
4743
2399
2810
3466
408
150
422
717
-72
56
57
59
4
0
1
C code function:
bmp180_get_cal_param
bmp180_get_ut
BMP180_get_up
BMP180_get_temperature
temp in 0.1°C
BMP180_calpressure
press. in Pa
type:
short
short
short
unsigned short
unsigned short
unsigned short
short
short
short
short
short
long
short (0 .. 3)
long
long
long
long
long
long
long
long
long
long
long
long
long
unsigned long
long
long
long
long
long
long
long
Page 15
Bosch Sensortec