Controlling Sensor Through Labview: Role of Diode?

[georgeh]

Can you guys look at the attached file. I have a sensor hooked up to a plug box. My question is, i am suppose to control the sensor through labview. My question is, how does the diode play a role? I would technically send the commands to the 1st input right? and if i wanted to read data, i could rea dit off the output, where the diode sends the voltage to?
Or am I getting this wrong?
thank you in advance.

 

[berkeman]

Do you have specs on the sensor? The hookup doesn't make sense to me at first glance. Is that meant to be a stiff 5V rail there? What about the ground and other connections?

 

[georgeh]

Do you have specs on the sensor? The hookup doesn't make sense to me at first glance. Is that meant to be a stiff 5V rail there? What about the ground and other connections?

I do have specs on it. This is just a small diag. I have it hooked up to some other hardware and it is grounded btw.link:
http://www.sensirion.com/images/getFile?id=25

 

[berkeman]

I do have specs on it. This is just a small diag. I have it hooked up to some other hardware and it is grounded btw.link:
http://www.sensirion.com/images/getFile?id=25

The thumbnail drawing seems wrong now. Look at the hookup diagram in Figure 2 in the datasheet. You communicate with this sensor with a serial interface, SCK and SDATA. From Labview, you will either need to define a serial interface model (I don't know if one exists already in Labview), or you will need to bit-bang two digital lines to emulate the digital master. Since the serial interface has only one SDATA line, you need to be able to switch from driving to just reading (Tri-State the output at times when the sensor is supposed to send data back).

 

[georgeh]

The thumbnail drawing seems wrong now. Look at the hookup diagram in Figure 2 in the datasheet. You communicate with this sensor with a serial interface, SCK and SDATA. From Labview, you will either need to define a serial interface model (I don't know if one exists already in Labview), or you will need to bit-bang two digital lines to emulate the digital master. Since the serial interface has only one SDATA line, you need to be able to switch from driving to just reading (Tri-State the output at times when the sensor is supposed to send data back).

Yeah. I am looking at figure two. I am bit banging the sensor. I am emulating the sck and writing to data port and reading off it using a connector box via L.V.

 

[berkeman]

Yeah. I am looking at figure two. I am bit banging the sensor. I am emulating the sck and writing to data port and reading off it using a connector box via L.V.

So is it working now?

 

[georgeh]

negative sir.

 

[berkeman]

Don't call me sir. I work for a living. (quiz question -- what movie is that from?)

Well, what's not working? Are you seeing the correct SCLK and SDATA waveforms like in the datasheet, but the RX data coming back is wrong? You're using the hookup diagram from the datasheet and not the one with the diode that you drew at the top of the thread, right? Do you have any way to post a plot of what your SCLK and SDATA look like?