NI DAQ6009 with sensor and LabVIEW

[Ails26]

I am using the NI DAQ6009 and I trying to attach a four sensitive resister sensor to it. I have placed a resistor in the circuit so the voltage divider rule is applied but I am unsure which channels to use? At the moment I have the 5Volts on the digital side connected to the sensor and resistor. I have the GND from the digital connected to the first GND channel on the analogue side and the other end of the sensor resistor wire attached to Ai0 is this correct??

Please help

thanks

[Joel_G]

Hi,

Please could you attach your code?

Thanks,

Kind regards,

[Ails26]

I am very new so my code is very basic!! wen I press on the Force sensitive resistor the signal cannot be seen on the waveform graph when no pressure is applied the graph has lines going everywher. I was trying to get the waveform graph to be on the correct scale so you can see when the sensor is pressed.

I hope you can help me i'm really trying to grt used to programming but i'm very bad

[Joel_G]

Hi,

I think you may have wired the sensor in slightly wrong, please refer to the wiring diagram below for reference.

You can adjust the scaling of the graph by right clicking on it and selecting properties, then going to the scales tab, unticking autoscale and entering your desired min and max values. You can also double click on the min and max values on the front panel to change them.

Kind regards,

[Ails26]

I have been trying all wknd and an the sensor is working and have attached a pic of how i attached the wires to see is it done correctly. I was wondering is it possible to have a max and a min line on the graph when the program is running! the aim is that when the ampliture goes over 5 then a massage will pop up on the user interface saying to much pressure applied! Is this possible to do?

Thanks

[Ails26]

Sorry the PIC

[Joel_G · Accepted solution]

I'm afraid I don't see your picture, I'm not sure if it attached correctly. However I think the reason you aren't seeing accurate measurements is that you're doing a resistance measurement with the DAQ assistant but you should be doing a voltage measurement.

The task you mention isn't too difficult, you just need to compare your signal to your thresholding values using the comparison pallette (Functions >> Programming >>Comparison from the block diagram) and then use the output of this to cause a dialog box to pop up (perhaps using a case structure).

To draw the two threshold lines on your graph you could just have another signal which is constant at the value of your threshold and output it to the graph as an additional channel, you can have multiple signals on the same graph using the merge signals function.

Good Luck,

Kind regards,