2014
Reading Temperature from TMP102 (Temperature
Sensor) using Raspberry Pi
Author: Praveen Kumar R
#9/3,Shree Lakshmi complex,2nd Floor,Opp,To Vivekananda Park,Girinagar,Bangalore-560085.www.tenettech.com
Introduction:
The TMP102 temperature sensor breakout from Sparkfun is an easy to use
thermometer that connects via I2C. This quick example shows how to use a TMP102
with Raspberry Pi and some simple Python code to get the current temperature.
Step 1:
Prerequisites
Run the following commands to install required packages:

sudo apt-get update

sudo apt-get upgrade

sudo apt-get install i2c-tools

sudo apt-get install python-smbus
Step 2:
Enabling I2c device in Raspberry Pi. Pi is ready to go with I2C as far as enabling the
hardware goes. You will need to open LX Terminal and enter the following command:
sudo nano /etc/modules

And add these two lines to the end of the file:

i2c-bcm2708

i2c-dev
#9/3,Shree Lakshmi complex,2nd Floor,Opp,To Vivekananda Park,Girinagar,Bangalore-560085.www.tenettech.com
Step 3:
Depending on your distribution, you may also have to edit a file which comes under

sudo nano /etc/modprobe.d/raspi-blacklist.conf
blacklist spi-bcm2708
blacklist i2c-bcm2708
Edit and comment the above two lines by putting a “#” infront of them
#blacklist spi-bcm2708
#blacklist i2c-bcm2708
Step 4:
Now add a new user to the i2c group:

sudo adduser pi i2c
#9/3,Shree Lakshmi complex,2nd Floor,Opp,To Vivekananda Park,Girinagar,Bangalore-560085.www.tenettech.com
Step 5:
Reboot the machine by sudo reboot

sudo reboot
Step 6:
Connections: (GPIO.BOARDSetmode)
TMP102
Raspberry Pi
GND
PIN 6
SCL
PIN 5
SDA
PIN3
V+
3.3v
ADD0
GND(PIN 9)
When connected as above, the TMP102 uses the I2C address 0x48. To confirm this, run
the following at the command line:

sudo i2cdetect -y 1
#9/3,Shree Lakshmi complex,2nd Floor,Opp,To Vivekananda Park,Girinagar,Bangalore-560085.www.tenettech.com
The resulting diagram should show the device at 0x48 by printing 48 in the
corresponding cell.
Code
import smbus
import time
bus = smbus.SMBus(1)
data = bus.read_i2c_block_data(0x48, 0)
msb = data[0]
lsb = data[1]
print (((msb << 8) | lsb) >> 4) * 0.0625
#printing the temperature value in
Celsius.
#9/3,Shree Lakshmi complex,2nd Floor,Opp,To Vivekananda Park,Girinagar,Bangalore-560085.www.tenettech.com
Execution of the code:
sudo python tmp102.py
Training
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Youtube channel
For queries: [email protected]
Contact: 080-26722726
#9/3,Shree Lakshmi complex,2nd Floor,Opp,To Vivekananda Park,Girinagar,Bangalore-560085.www.tenettech.com