-
Notifications
You must be signed in to change notification settings - Fork 2
/
altitude.py
60 lines (49 loc) · 1.91 KB
/
altitude.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
# Distributed with a free-will license.
# Use it any way you want, profit or free, provided it fits in the licenses of its associated works.
# MPL3115A2
# This code is designed to work with the MPL3115A2_I2CS I2C Mini Module available from ControlEverything.com.
# https://www.controleverything.com/products
import smbus
import time
# Get I2C bus
bus = smbus.SMBus(1)
# MPL3115A2 address, 0x60(96)
# Select control register, 0x26(38)
# 0xB9(185) Active mode, OSR = 128, Altimeter mode
bus.write_byte_data(0x60, 0x26, 0xB9)
# MPL3115A2 address, 0x60(96)
# Select data configuration register, 0x13(19)
# 0x07(07) Data ready event enabled for altitude, pressure, temperature
bus.write_byte_data(0x60, 0x13, 0x07)
# MPL3115A2 address, 0x60(96)
# Select control register, 0x26(38)
# 0xB9(185) Active mode, OSR = 128, Altimeter mode
bus.write_byte_data(0x60, 0x26, 0xB9)
time.sleep(1)
# MPL3115A2 address, 0x60(96)
# Read data back from 0x00(00), 6 bytes
# status, tHeight MSB1, tHeight MSB, tHeight LSB, temp MSB, temp LSB
data = bus.read_i2c_block_data(0x60, 0x00, 6)
# Convert the data to 20-bits
tHeight = ((data[1] * 65536) + (data[2] * 256) + (data[3] & 0xF0)) / 16
temp = ((data[4] * 256) + (data[5] & 0xF0)) / 16
altitude = tHeight / 16.0
cTemp = temp / 16.0
fTemp = cTemp * 1.8 + 32
# MPL3115A2 address, 0x60(96)
# Select control register, 0x26(38)
# 0x39(57) Active mode, OSR = 128, Barometer mode
bus.write_byte_data(0x60, 0x26, 0x39)
time.sleep(1)
# MPL3115A2 address, 0x60(96)
# Read data back from 0x00(00), 4 bytes
# status, pres MSB1, pres MSB, pres LSB
data = bus.read_i2c_block_data(0x60, 0x00, 4)
# Convert the data to 20-bits
pres = ((data[1] * 65536) + (data[2] * 256) + (data[3] & 0xF0)) / 16
pressure = (pres / 4.0) / 1000.0
# Output data to screen
print "Pressure : %.2f kPa" %pressure
print "Altitude : %.2f m" %altitude
print "Temperature in Celsius : %.2f C" %cTemp
print "Temperature in Fahrenheit : %.2f F" %fTemp