How to Interface small radar with GPIO

[camillerufu]

Hello,

I want to interface small "Radar motion detector" with Raspberry Pi GPIO input.
The hardware interface is :
Pin / Colour / Description / Function
1 / Black / GND / Ground, Reference potential
2 / Brown / OUT / Open Collector output
4 / Red / VCC / Operating voltage 8 ... 15V
Documentation writes : "The open collector transistor output connects against ground on recognizing movement. ".
How to connect this small board to raspberry in order to read periodically the output event ?

Complete documentation is on :https://shop.bb-sensors.com/en/Motion-b ... ation.html

Best regards

[joan]

You will need an external power supply.

Connect the ground of the external power supply to the Pi.
Connect the output to any spare GPIO, set the GPIO as an INPUT and enable the internal pull-up to 3V3.

The GPIO will read 1 when no object is detected and will read 0 when an object is detected.

[camillerufu]

Hello,
You mean to connect the ground of the external power supply (8-12 V DC) which power the Radar module, to one of the Pi GPIO Ground pin (for exemple GPIO pin #9) ?

This will put the both system (external power supply ground and GPIO ground) to the same level ? there is no problem ?

Best regards ?

[joan]

Hello,
You mean to connect the ground of the external power supply (8-12 V DC) which power the Radar module, to one of the Pi GPIO Ground pin (for exemple GPIO pin #9) ?

This will put the both system (external power supply ground and GPIO ground) to the same level ? there is no problem ?

Best regards ?

To get a signal from the device you need to connect the ground of the device to a Pi ground and the out pin of the device to a Pi GPIO.

The grounds of the device and external power supply will be the same. Use whichever grounds are most convenient.