Raspberry pi Temperature Sensor Howto

System

– Get a good SDCARD, any SDHC 16GB Class 10
– Get an Image
I have choosen the Raspbian

– Image to sdcard:
gparted /dev/sde
delete all
write
add fat32, write
dd bs=4M if=2014-01-07-wheezy-raspbian.img of=/dev/sde

Temperatur-Sensor

– Install WiringPi & gpio

git clone git://git.drogon.net/wiringPi
cd wiringPi
./build uninstall
./build
- Test gpio
gpio -v
gpio readall

vi /boot/config.txt 
dtoverlay=w1-gpio,gpiopin=4,pullup=on

vi /etc/modules
w1-therm
w1-gpio pullup=1

 

reboot

 

wiring diagram:

Resistor: 4,7k

 

Sensor:
something like:
cat /sys/bus/w1/devices/10-000802c2dceb/w1_slave

will output:
2d 00 4b 46 ff ff 03 10 dd : crc=dd YES
2d 00 4b 46 ff ff 03 10 dd t=22562

write a bash script:

#! /bin/bash
tempread=`cat /sys/bus/w1/devices/10-000802c2dceb/w1_slave`
temp=`echo $tempread | egrep -o '.{5}$'`
temp2=`echo "scale=2; $temp / 1000" | bc`

echo $temp2

will output:
22.68