Raspberry Pi SHT25 Sensor Python Tutorial

About This Project:

SHT25 I2C Humidity and Temperature Sensor ±1.8%RH ±0.2°C I2C Mini Module. The SHT25 high-accuracy humidity and temperature sensor has become an industry standard in terms of form factor and intelligence, providing calibrated, linearised sensor signals in digital, I2C format. Here is the demonstration with a Python code using Raspberry Pi.

Step 1 : What you Need!!

1. Raspberry Pi

2. SHT25

LINK : https://www.controleverything.com/content/Humidity...

3. I²C Cable

LINK : https://www.controleverything.com/content/I2C-Cabl...

4. I²C Shield for Raspberry Pi

LINK : https://www.controleverything.com/content/I2C-Mast...

5. Ethernet Cable

Step 2 : Connections

Take a I2C shield for raspberry pi and gently push it over the gpio pins of raspberry pi.

Then connect the one end of I2C cable to SHT25 sensor and the other end to the I2C shield.

Also connect the Ethernet cable to the pi or you can use a WiFi module.

Connections are shown in the picture above.

Step 3 : Code

The python code for SHT25 can be downloaded from our github repository- ControlEverythingCommunity

Here is the link for the same :

https://github.com/ControlEverythingCommunity/SHT25/blob/master/Python/SHT25.py

We have used SMBus library for python code, we can install SMBus on raspberry pi by following the steps described here:

https://pypi.python.org/pypi/smbus-cffi/0.5.1

You can also get the code from here, its mentioned below :

# 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.
# SHT25
# This code is designed to work with the SHT25_I2CS I2C Mini Module available from ControlEverything.com.
# https://www.controleverything.com/content/Humidity?sku=SHT25_I2CS#tabs-0-product_tabset-2
import smbus
import time
# Get I2C bus
bus = smbus.SMBus(1)
# SHT25 address, 0x40(64)
# Send temperature measurement command
#		0xF3(243)	NO HOLD master
bus.write_byte(0x40, 0xF3)
time.sleep(0.5)
# SHT25 address, 0x40(64)
# Read data back, 2 bytes
# Temp MSB, Temp LSB
data0 = bus.read_byte(0x40)
data1 = bus.read_byte(0x40)
# Convert the data
temp = data0 * 256 + data1
cTemp= -46.85 + ((temp * 175.72) / 65536.0)
fTemp = cTemp * 1.8 + 32
# SHT25 address, 0x40(64)
# Send humidity measurement command
#		0xF5(245)	NO HOLD master
bus.write_byte(0x40, 0xF5)
time.sleep(0.5)
# SHT25 address, 0x40(64)
# Read data back, 2 bytes
# Humidity MSB, Humidity LSB
data0 = bus.read_byte(0x40)
data1 = bus.read_byte(0x40)
# Convert the data
humidity = data0 * 256 + data1
humidity = -6 + ((humidity * 125.0) / 65536.0)
# Output data to screen
print "Relative Humidity is : %.2f %%" %humidity
print "Temperature in Celsius is : %.2f C" %cTemp
print "Temperature in Fahrenheit is : %.2f F" %fTemp

Step 4 : Applications

SHT25 temperature and relative humidity sensor has various industrial applications like temperature monitoring, computer peripheral thermal protection and so on..