raspi_temp_datalogger

This is an lite temperature datalogger for the Raspberrypi, it works with the Dalla ds1820 OnWire Sensors. Its tested with 3 Sensors, but it might be work with more than 3 ...

Hardware

The One Wire Data Line is Conected to GPIO4 (P1.7). Data is conected to VCC with an Pullup-Resistor(4k7).

Configuration of the OneWire KernelModul

Aktivate the Modul:

   pi@raspi:~$ sudo modprobe w1_gpio
   pi@raspi:~$ sudo modprobe w1_therm

Look if the Modul ist already loaded:

   pi@raspberrypi ~ $ lsmod
   Module                  Size  Used by
   w1_therm                2705  0 
   w1_gpio                 1283  0 
   wire                   23530  2 w1_gpio,w1_therm
   cn                      4649  1 wire
   snd_bcm2835            19889  0 
   snd_pcm                74834  1 snd_bcm2835
   snd_seq                52536  0 
   snd_timer              19698  2 snd_seq,snd_pcm
   snd_seq_device          6300  1 snd_seq
   snd                    52489  5 snd_seq_device,snd_timer,snd_seq,snd_pcm,snd_bcm2835
   snd_page_alloc          4951  1 snd_pcm
   evdev                   8682  0 
   joydev                  9102  0 
   pi@raspberrypi ~ $ 

-> It look that it is loaded right.

Looking for OneWire temperature Sensors:

  pi@raspberrypi ~ $ ls /sys/bus/w1/devices
  10-0008021dad2e  w1_bus_master1
  pi@raspberrypi ~ $

The Directory which starts with "10-" is the Sensor.

Read One Sensor:

pi@raspberrypi ~ $ cat /sys/bus/w1/devices/10-0008021dad2e/w1_slave
25 00 4b 46 ff ff 05 10 5d : crc=5d YES
25 00 4b 46 ff ff 05 10 5d t=18437
pi@raspberrypi ~ $ 

t=18437 means 18,437 Degree Celsius.

The Log Programm

compile the prgramm with make and run it with:

pi@raspberrypi ~ $ nohup raspi_temp_datalogger > logdata.csv &

The nohup output can be used in MsExel, LibreCalc, OoCalc or so on ...