Filtering signal to prevent flickering of the output.

[darrencgray]

Hello

I am using Labview 2010 and a usb 6008 DAQ to acquire two signals from  a 555 timer circuits with LDRs and  I am measuring them and comparing them. The idea is that when one of them is greater than the other I will generate an output. My problem is that even though I have allowed for +- 10 tolerence , I am still getting a flickering output once the treshold has been exceeded. Can someone give me any ideas because maybe I am approaching this completely the wrong way. The VI I have attached is using a simulate signal tool to represent my input signal.

Bye

[Andy.G]

Hello Darren,

I presume that the 555 timers are producing the signal for a light source and that the LDR are triggered off that source? Are the LDRS completely shielded from alternate light sources? What output are you generating? Can I see the code you are using for the acquisition on the DAQ side?

[darrencgray]

Hello

The 555 timer circuits are producing the signal to be compared with each other and motors will turn depending on which on has the greater frequency. The output I am generating is for driving stepper motors hence the reason for producing the pulse in the case structure.

Thank you

[Andy.G]

Hello Darren,

Is there any reason you haven't considered SoftMotion for your application? As far as exactly what you are trying to achieve with the timers Im still a bit lost as to what the problem is? What behavior are you seeing that is unexpected? So from what I gather is that you are measuring two frequencies and trying to establish which one is greater? I have written a VI to show you a simple yet effective way of doing just that. I have modeled it appropriately for the up and coming red nose day. Please see attached code. Enjoy!