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pi:temperature

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Temperature sensors

18B20 (digital)

Wiring:

  • Waterproof:
    • Red: 3.3V
    • Yellow: 4.7 k pull-up (5.1k fine) and gpio pin nominated in /boot/config.txt
    • Black: ground
  • Kit module:
    • 1 (labelled -): ground
    • 2: 3.3V
    • 3 (labelled S): 4.7k pull-up and signal

At the end of /boot/config.txt (replace 21 with pin number):

dtoverlay=w1-gpio,gpiopin=21

Save and reboot.

ls -l /sys/bus/w1/devices

Grab its address (format 28-xxxxxxxxxxx). Read the temperature with

cat /sys/bus/w1/devices/28-[address]/w1_slave

The numerical value after t= is the temperature in thousandths of a degree C.

pi/temperature.1512309556.txt.gz · Last modified: 2019/11/07 17:58 (external edit)