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Getting a different sensor ID with 1 wire plus

1633 Views - Created 29/09/2016

29/09/2016

Posted by:
sam

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I am using the 1 wire pi plus board to connect DS18B20 sensor to pi. I have followed the instructions to  Install OWFS and Python-OW from your website and made the connections as below

OW is connected to 

VDD from sensor to 5V on the board

GND from sensor to GND on the board

DQ from sensor to OW on the board

I am reading temperature and the sensor ID is 28.FF10B7A11504

But when I connect the same sensor and read the sensor ID using W1-GPIO and W1-therm I get 28-0415a1b710ff

The DS18B20 sensor is supposed to have a unique ID then why I am getting two different sensor ID?

Is my connection Correct?

Thanks

29/09/2016

Posted by:
andrew

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Location:
United Kingdom

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Hi

Your connection between the DS18B20 and the 1 Wire Pi Plus is correct.  I am not sure why the ID is showing differently on python-ow and W1-GPIO, it could possibly be that the two libraries interperate the ID in a different way.  If you can read the ID and temperature using the 1 Wire Pi Plus then the sensor is working correctly.

AB Electronics UK Tech Support

19/10/2016

Posted by:
sam

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Quote from andrew
HiYour connection between the DS18B20 and the 1 Wire Pi Plus is correct.  I am not sure why the ID is showing differently on python-ow and W1-GPIO, it could possibly be that the two libraries interperate the ID in a different way.  If you can read the ID and temperature using the 1 Wire Pi Plus then the sensor is working correctly.

Thanks. I want to connect 25nos DS18B20 sensors to 1 Wire Pi Plus. The total distance is 50m.

what type of cable should be used, Cat5? 

I found the following explanation on wire connection "data & ground using one twisted pair and power & ground using a second twisted pair." is this correct?

19/10/2016

Posted by:
andrew

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Location:
United Kingdom

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Cat 5 cable should work fine for connecting your sensors using the way you described.

AB Electronics UK Tech Support

04/11/2016

Posted by:
RockyFath

Last edited: 25/01/2017

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Location:
UK

Hi..i am a new suer here. I am also not getting why the ID is showing differently on python-ow and W1-GPIO, it could possibly be that the two libraries interperate the ID in a different way.  If you can read the ID and temperature using the 1 Wire Pi Plus then the sensor is working correctly.

pcb assembly shenzhen

Rocky

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