12-03-2008 10:45 AM
I am interested in using a wireless switch to indicate whether a device is holstered/unholstered. I found the following switch which I think would meet my needs. http://www.walgreens.com/store/product.jsp?id=prod3447901&CATID=304722&skuid=sku3446744&V=G&ec=frgl_559044&ci_src=14110944&ci_sku=sku3446744
How do I tap into the on/off state of the light receiver and input that data into labview? Obviously when the switch is on, the receiver circuit outputs a voltage. How can I measure this voltage & input it into labview? What data acquisition card do I need and is there anything else I need to convert this voltage/lack of voltage into something the daq can read & understand?
Thank you.
-Adam
12-03-2008 10:56 PM - edited 12-03-2008 10:59 PM
Hi Adam,
I like the way you think! I once modified a cheap programmable appliance timer to switch AC based on a parallel-port output pin (using LabVIEW, of course.)
I expect if you crack-open and probe-around in the "light receiver" you'll find some TTL level signal that indicates whether the light is on or not. BE CAREFUL to identify and stay-away-from the AC side of things!!! Also, while probing, be very very careful not to accidentally short-together any signals - especially neighboring pins on ICs.
If you're lucky, you'll be able to (find and) wire such signal to a PC parallel-port input without affecting the operation of the light.
I think appropriate voltages for the parallel port are 0-5V DC. If you find a signal in the -12 to +12V range, consider using a COM port instead.
You can find examples on this forum to use VISA to read parallel port signals or COM port signals.
Luck/Cheers!