Print PDF
Favorite
Email
Step 4Make the sensors and the network
When wiring up your 1wire network, you wan to use cat 5 network cables.
I have had some bad experiences using other cables, and with combining different types of cable.
When running over cat5, the 1wire bus can have quite long cables.
In one weatherstation setup, I run a 30 meter cat5 from a technical room with a Linux computer and up to the roof. On the roof, the cable is split into 3 5-15 meter long cables with a sensor at the end of each one. This setup works flawlessly. The 1-wire network is quite robust.
Making the sensor:
You want to make the sensor both waterproof, and rigid.
1)
Cut a Cat 5 cable to the desired length.
2)
De-insulate the sensor end.
Cut off 3 of the 4 pairs, leaving the green/whitegreen one.
3)
Slide a small shrink tube over the green wire.
4)
Solder the green wire to the middle pin of the DS1820
5)
Pull the the shrink tube up, so it covers all the metal of the middle leg and the metal of the wire connected to it. Then heat it with a lighter or heat gun to shrink it in place
6)
Solder the white/green wire to the two other pins.
7)
Put a larger shrink tube over the sensor and the cable.
See the picture.
Then heat it gently with a lighter to shrink in place.
You don't want to set the thing on fire, just hold the flame 4-10mm away from the shrink tube.
8)
Put your sensors wherever you want to have them, connect to the rs232 interface and plug into your computer.
I have had some bad experiences using other cables, and with combining different types of cable.
When running over cat5, the 1wire bus can have quite long cables.
In one weatherstation setup, I run a 30 meter cat5 from a technical room with a Linux computer and up to the roof. On the roof, the cable is split into 3 5-15 meter long cables with a sensor at the end of each one. This setup works flawlessly. The 1-wire network is quite robust.
Making the sensor:
You want to make the sensor both waterproof, and rigid.
1)
Cut a Cat 5 cable to the desired length.
2)
De-insulate the sensor end.
Cut off 3 of the 4 pairs, leaving the green/whitegreen one.
3)
Slide a small shrink tube over the green wire.
4)
Solder the green wire to the middle pin of the DS1820
5)
Pull the the shrink tube up, so it covers all the metal of the middle leg and the metal of the wire connected to it. Then heat it with a lighter or heat gun to shrink it in place
6)
Solder the white/green wire to the two other pins.
7)
Put a larger shrink tube over the sensor and the cable.
See the picture.
Then heat it gently with a lighter to shrink in place.
You don't want to set the thing on fire, just hold the flame 4-10mm away from the shrink tube.
8)
Put your sensors wherever you want to have them, connect to the rs232 interface and plug into your computer.
| « Previous Step | Download PDFView All Steps | Next Step » |
In non-parasitic mode (2 more components required) 10 or 12 would be quite happy. With a separate 5 volt PSU, several thousand.