how to connect sht71 with ni pci 6221

[khairulazharthajmy]

hi...i'm khairul azhar.a student.my final project is to control Air Cond blower by using temperature and humidity as data reference.How i can connect my SHT71 with DAQAssistant NI PCI 6221?

[MattBradley]

Is this the sensor you're using?

http://www.sensirion.com/en/01_humidity_sensors/05_humidity_sensor_sht71.htm

It looks like it has its own digital interface.  You will have to hookup two digital lines on the 6221 to the SHT71.  In terms of communicating, you will have to right some low level drivers.  There are some C examples on the website that should be useful, but you will have to translate them to LabVIEW.

[khairulazharthajmy]

which menas i can't connect sht71 directly to NI PCI 6221 even it has digital input port?can u give me the URL to the example u said?thank you

[Dennis_Knutson]

Matt gave you the URL. Why don't you just go there and look? The sample code link is right along with the rest of the app notes.

You can connect the sensor to the 6221 but what you will have to do is duplicate the communication protocol that is described in the datasheet. That means providing SCK and sending and receiving data per section 3 of the datasheet. It says that the interface consists of static logic so you don't have to worry about running the digital I/O at any specific frequency.

[khairulazharthajmy]

Thank You

[MattBradley]

Thank you Dennis.  Couldn't get back here earlier (on Friday, I teach class at the local JC).