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Chaining Sensirion SHT7x sensors?

E

Elias Aarnio

Jan 1, 1970
0
Hello,

I am looking forward to do some humidity monitoring with Sensirion
SHT75 sensors.

Has anybody any experience on how to chain several of these to a
single loop?

Any pointers to (preferably Linux) software.

I am aware of the Windows-software and schematics at
http://peterpolm.tripod.com/sht11/id1.html
 
C

Charles Edmondson

Jan 1, 1970
0
Elias said:
Hello,

I am looking forward to do some humidity monitoring with Sensirion
SHT75 sensors.

Has anybody any experience on how to chain several of these to a
single loop?

Any pointers to (preferably Linux) software.

I am aware of the Windows-software and schematics at
http://peterpolm.tripod.com/sht11/id1.html
You will probably have a problem. These units are address driven, but
IIRC, the address is set at the factory, and they are all the same
address. You need to have separate clock signals to each unit (or gate
the clock to each unit) to address multiple units on the same bus.
 
E

Elias Aarnio

Jan 1, 1970
0
Charlie,

Thanks for your advice

You will probably have a problem. These units are address driven, but
IIRC, the address is set at the factory, and they are all the same
address.

And the address is not user configurable, I guess... too bad. Well -
there is always the low end solution - using same amount of buses as
sensors.

I wonder how the Sensirion people have designed their evaluation kit that
seems to be able to handle up to 20 sensors? Separate interfacing
circuitry for each sensor?
http://www.sensirion.com/en/sensors/humidity/EK-H3.htm
 
C

Charles Edmondson

Jan 1, 1970
0
Elias said:
Charlie,

Thanks for your advice

Mon, 05 Apr 2004 12:45:39 -0700, Charles Edmondson wrote:




And the address is not user configurable, I guess... too bad. Well -
there is always the low end solution - using same amount of buses as
sensors.

I wonder how the Sensirion people have designed their evaluation kit that
seems to be able to handle up to 20 sensors? Separate interfacing
circuitry for each sensor?
http://www.sensirion.com/en/sensors/humidity/EK-H3.htm
They probably have a micro with separate buses to each sensor. You can
connect them all to the same data line, it is the clock that controls
the chip. Uses a little non-standard format on the interface, as well. :-('
 
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