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Biamp Cornerstone

Using an input for a movement sensor (PIR)

You can one of the inputs on any of the Impera controllers to trigger any action from the activity of the movement sensor.

The 3rd party movement sensor sold by Biamp is a Normally Closed version meaning that when activity is detected, the contacts are opened.

So in Biamp Project Designer you should remember to set the "Movement when" to HIGH

Below is a diagram that shows the wiring to make it work with our PIR sensor.

First, you start in System and insert a Movement sensor (PIR) from the Biamp->Digital inputs/Outputs category.

Using an input for a movement sensor 1.png

Then you go to Feedback and define the actions you will need the controller to perform when either detecting movement or as often used when no movement is detected for an amount of time!

Use the "Press button" action to press the power off for example.

Using an input for a movement sensor 2.png


Remember that the GPIO input is looking for voltages above or below the following thresholds:

  • Input trigger low: < 1VDC
  • Input trigger high: > 4VDC

When in doubt, use a multimeter to measure the output of the switch or sensor and document the findings. Then connect the switch or sensor to the GPIO and take the measurements again. In some applications, the sensor output may not pull the circuit down below the 1VDC threshold. If this is the case, a resistor can be added to the circuit in series or parallel with the sensor. Measure and test until expected functionality is achieved.

24VDC is a common sensor logic output used as the 'High' output of sensor; when connected to the GPIO of an Impera controller, the 'Low' output may only pull down to 3VDC. This will not pull down far enough to trigger the 'Low' so applying a 4.7k or 10k ohm resistor to the circuit will change the measured 'High' and 'Low' to operate within the proper range.

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