Rocode >> Hobbies >> Sensors
1-wire Temperature Sensor and LED Display
I have updated my temperature sensor using 1-wire technology with a LED Display.
I use a DS9490R-P 1-Wire USB Adaptor from Hobby Boards.
I added a Digital Thermal Probe or Sensor DS18B20 from ebay for $3.
Using a new crimping tool, a RJ12 connector and 1 meter of flat telephone wire. I connected the wire to the RJ12 connector and then soldered the other end to the lead of the DS18B20.
I added a mini speaker from ebay for $4.
The temperature from the Thermal Probe is forward via Elvin notifications to the remote computer(s) running ticker or to remote LED display(s).
I have an hourly temperature report that is shown on the LED Display accompanied by a short audible message. Here is a video showing a temperature report at 3pm local time.
I installed owserver, owhttpd and owfs to my Fedora Linux computer.
I got them working using the follow instructions.
I put the 3 commands from the above page into a service file called /etc/rc.d/init.d/owfs.
This starts the 1-wire system on boot and creates a /1-wire directory on the filesystem.
I updated my /usr/local/bin/weatherchecker.sh script with code, to emit ticker and led display messages, as shown
I then added a cron entry to call this script each hour. i.e in /etc/crontab:
Here is how the Elvin notification looks on my Windows 7 desktop.
This says that the recorded temperature at 4pm on the 1st was 24.0 degrees celsius.
Here is a brief history of readings as stored in Sticker.
The 85.0 degree readings are an intermittent error that I now filter out.
Here in the script that calls espeak to synthesize any messages that accompany the LED display output.
A curfew is programmed between 10pm and 8am.