Distance between Sensirion and Basic Stamp 2.

markuster

Hi,

Only to know the maximum length of the cable I could
use between the Sensirion sensor (code 28018) and the basic
stamp 2 module.


Thanks, Mark.

WBA Consulting

A lot farther than you might think. Look at post #9 on this thread where I was using 208 feet of Cat5 cable between a BS2 and SHT11. If you have issues with communication due to length (caused by slow rise times from capacitance in the wire), you can slow down the clocking of the SHT11. It does not care how slow you clock it, even a 1 hz clock rate will work. There are also more examples and notes on my page for my SHT11 module. Use the links at the top of that page and look at the code examples page. And lastly, if you do a search on the forums for "sensirion clock" you will find some other threads discussing similar questions.

markuster

Thanks Andrew:

It seems that the SHT11 you have is different to the Parallax Sensirion.
Perhaps for this reason you can use 208 feet of Cat5 cable.

Could you confirm please ?

Thanks, Mark

WBA Consulting

Yes and no. The SHT11 is exactly the same, I just added a few things in my form factor to "bulletproof" it's overall functionality to make it's use easier. You can do the same with the Parallax DIP8 version by adding an inline protection resistor for the clock line, a pull-down for the clock, and a filter cap for Vdd. For long distances, if you add a cap and the clock pull down, it should work the same as mine.