Hola,
Buscando información sobre un sensor de temperatura y humedad, el SHT11, encontré esto en el foro
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1229870415/0
Dice que cambiando la pulsación se puede alargar hasta 40 metros. Yo necesito alargar 1.5 metros, todavía no he conseguido que me funcione.
I found another problem of the library and the answer.
When you connect the SHT-xx to arduino via a short cable(about 10cm), the library works fine.
But if you hook up the sensor with very long cable, you will get corrupted data.
The reason is that, the default clock pulse width is too short for the long cable.
You can easily fix the problem by only modifying two lines in the library file.
at hardware/libraries/Sensirion/Sensirion.cpp file,
before:
Code:
#define PULSE_LONG delayMicroseconds(3)
#define PULSE_SHORT delayMicroseconds(1)
after:
Code:
#define PULSE_LONG delayMicroseconds(300)
#define PULSE_SHORT delayMicroseconds(100)
With this fix, I can get correct data with using a 40 meter cable! Probably I can use more long cables.
Though I have not found the best width of the pulse, 300 and 100 usec delay doesn't cause any problems.