Wireless sensor

Hello all,

Hope you can help me with a project I am doing.

I have a very simple install with a PIR sensor to an Arduino UNO that triggers a video mapping in Isadora for a show.

I would like to replicate a similar install but wireless and using a RCWL-0516 microwave motion sensor. I am thinking in buying a MKR 1000 however the microwave motion sensor only works from a 4V DC input which the MKR 1000 does not provide.

My question is would a step up from 3.3V to 5V work?

I am new to Arduino and this might be a very basic question but I am just trying to have a bit of feedback from you guys before I purchase all the bits.

Thanks a lot in advance for any help you can give!!

Bests, Santiago

Santmart: ...sensor only works from a 4V DC input which the MKR 1000 does not provide.

It does provide 5V, from the 5V pin, if powered by USB. The sensor needs at least 4V, not exactly 4V. The output is 3.3V so can be connected directly to an input pin.

How do you plan to power the circuit?

How do you plan to connect it to the pc/Mac/laptop? If using serial cable, a mkr1000 seems overkill. A Nano or Pro Mini would be cheaper.

Hi Paul,

Sorry I should have said that my plan is to power it with a Lipo battery. The idea is that it all goes completely wireless. That's why I was thinking on the step up to go from 3.3V to 5V.


Li-po batteries are 3.7V, nominally, so you would want your boost module to take input directly from the battery, not from the 3.3V output of the Arduino. Doing that would put increased load on the Arduino's 3.3V regulator and more importantly, waste battery energy unessessarily.

Are you sure these modules will not work at 3.3V? Need to see a schematic of the sensor.

Found a schematic (rather blurred)

I was hoping to see a 3.3V regulator on the board, which could be bypassed. But it looks like the regulator is built into the main sensor chip.

Would 4xAA NiMH cells be an option instead of li-po? Not quite as compact, but would provide 4+V.

RCWL-0516 schematic.jpg

Clear schematic of the sensor and a lot more information here.

Everything in the sensor runs on 3.3V, so you could try applying voltage to the 3.3V output of the chip’s built in LDO regulator to power it. Let us know if this works.

Alternatively, use 3xAAA batteries to provide 4.5V and power the Arduino from the motion sensor’s 3.3V output.