Sensirion sht7x labview

[GHernandez]

Thanks for the upload. I am trying to test it on a PCI-6033E but i keep getting zero. I'll recheck the connections, I am not sure if this sensor is broken either. May also be that.

[MarioLutz]

Connect the clock line to port0.0 and the DATA line to port0.1 or like you want. No connections to other ports.
Then select in the SubVI "DAQ Initialize 2" these ports/pins and make sure for reading and writing data line there is the same port.
I forgot to take care of the error from the "s_softreset" There is an boolean output indicating an error from the reset of the sensor.
May you look at this. If there is an error for resetting the device cannot control the data line or it is broken. If you have an oscilloscope you can check the line. I also did this. The sensor was not able to pull down the line to ground (only half voltage) while connected to two ports from the previous configuration.

[GHernandez]

 Thank you very much. The 1st sensor I was trying was not working. I plugged in a second one and it worked!!
thanks a lot.

[chiryu]

I am trying to operate SHT15 sensor with NI card 6229 and labview 8,

and have just found that the software "SHTxx_driver-new.llb" uploaded

here by MarioLutz looked very helpful!

However, it didn't work properly for me; both humidity and temperature

readings are 0. Though the sensor seems to be acknowledging properly.

Can someone kindly look at the figure and give me an advice?

[MarioLutz]

I had the same picture like you on my oscilloscope . The Ack of the Sensor can not pull the line to ground (only half voltage).
Do you use only one digital port for reading and writing the DATA line like me? Maybe try to connect a pullup-resistor (4.7k-10k) from +5V to the DATA line.

[MarioLutz]

New connection diagram

SHTxx                              DAQ
______                          ___________________
GND   |-------------------------|   GND                       |
5V      |-----+------------------|  +5V                         |
CLK    |-----|-------------------| writing digital port 1    |
DATA  |-----|----------+-------| r/w digital port 2        |
______|     |           |       |___________________|
                +--###--+
                   Resistor

[chiryu]

Thank you very much for the advice. I use only one digital port for reading and writting the DATA line as you did.

I have just tried 10k pullup-resistor but still am not successful. I agree that we need the pullup-resistor, but I believe the high acknowledge voltage is another issue (Pullup-resistor cannot lower the voltage).
If you would let me know your idea again, I would really appreciate it.

[MarioLutz]

I did a very poor error handling.

In the main.vi remove everything except the DAQ_initialize, s_softreset and DAQ_close. Then connect a boolean indicator to the output of s_softreset. If the bool is true, the DAQ-card can not see the answer of the sensor. Then you can look with the oscilloscope again.
I know the problem that the pullup-resistor do not solve the problem with the ground problem. Try to increase the time (millisecond timer)
and make sure the pins/ports you use are correct in the DAQ_initialize.vi.
Sorry, this is all i can tell you. So for me and the other one its working with the same daq card family.

If you know C language and a little microcontroller programming you can look at the sample code from Sensirion. I use the code for the driver.
link: http://www.sensirion.com/images/getFile?id=92

Bye

Message Edited by MarioLutz on 08-08-2006 11:50 PM

[apauaie]

I managed to get the driver(SHTxx_driver_new) to work with SHT15 with NI Card 6229.... What i did is simply connect DATA line to another digital IO(ex: P2.0)... I got the same signal as chiryu before but after i connect DATA to a dummy line, i manage to get proper ack signal.....I don't know what happen but it definitely works....I think.... It's giving me 62% humidity and 23 for temperature.... seem about right.....Let me know if it works for you chiryu....

[sedao]

I have SHT75 and LV 8.0 with DAQ usb-6009. The code given by MarioLutz has been tested and worked properly. Right now I am thinking to reduce the resolution (Temp to 12bit and RH to 8bit) and get higher DAQ sampling rate.
Can anyone modify this code for me please?