# Looking for help on the motion sensor problems

**URL:** <https://discourse.processing.org/t/looking-for-help-on-the-motion-sensor-problems/34090>\
**Category:** Electronics (Arduino, etc.)\
**Created:** [December 13, 2021, 3:58am UTC](https://discourse.processing.org/t/looking-for-help-on-the-motion-sensor-problems/34090 "2021-12-13T03:58:30Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![kathy123td](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/kathy123td/32/15236_2.png) [@kathy123td](https://discourse.processing.org/u/kathy123td)\
**Post date:** [December 13, 2021, 3:58am UTC](https://discourse.processing.org/t/looking-for-help-on-the-motion-sensor-problems/34090/1 "2021-12-13T03:58:30Z")

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Hello, I replace a PIR Motion Sensor according to the[6 steps](https://www.kynix.com/Blog/6-Steps-to-Install-Motion-Sensor.html) in my phone.  
I followed the schema reported of product introduction and steps in the posted url, but it does not work, it gives me values not consistent with the movements.  
I am not so good in electronics, so I don’t know how to proceed.

The signal produced by the PIR is 0V when there is no motion, and 12V when some motion is sensed.  
I also tried to connect the signal produced with a series of two resistors: 14Kohm and 10Kohm. And then to the ground. In this way, the potential difference between the 10Kohm resistor and the ground should be 5 volts when some motion is sensed. Anyway it does not work!

Can anyone help me?

![image](https://canada1.discourse-cdn.com/flex036/uploads/processingfoundation1/original/2X/1/199ccfdc3e1f62568659076329ef867b3606e488.png)

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<div class="post-metadata">

**Author:** ![jafal](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/jafal/32/19112_2.png) [@jafal](https://discourse.processing.org/u/jafal)\
**Post date:** [December 13, 2021, 4:44am UTC](https://discourse.processing.org/t/looking-for-help-on-the-motion-sensor-problems/34090/2 "2021-12-13T04:44:05Z")

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Hi

Read the Data sheet and pins configuration for your module in general the output must be TTL not 12 volt this voltage refers to power supply

 ![Screenshot_2021-12-13-06-38-56-829](https://canada1.discourse-cdn.com/flex036/uploads/processingfoundation1/original/2X/b/b3787c23a37ef39019fd0392011f7748fc8ee123.jpeg)  
 ![Screenshot_2021-12-13-06-39-21-644](https://canada1.discourse-cdn.com/flex036/uploads/processingfoundation1/original/2X/6/6c4fa4b479e20ed4cbf830d0473ff368a6be0b44.jpeg)

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**Author:** ![glv](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/glv/32/18785_2.png) [@glv](https://discourse.processing.org/u/glv)\
**Post date:** [December 13, 2021, 11:10am UTC](https://discourse.processing.org/t/looking-for-help-on-the-motion-sensor-problems/34090/3 "2021-12-13T11:10:04Z")

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Hello,

What PIR are you using?

> [@kathy123td](#):
>
> The signal produced by the PIR is 0V when there is no motion, and 12V when some motion is sensed.

A simple voltage divider is _ **one way** _ to do level translation.

_ **If you are using a 12V system** _ with a _ **12V signal output** _ then you will need to drop the 12V output to 5V input to Arduino (this may be 3.3V on some Arduinos) as you have done with your voltage divider.

12V \* 10 /(10+24) ohms will give you 5V.

The circuit diagram that you provided is _ **missing a common ground** _ from the PIR to the ground of the Arduino.

> [@kathy123td](#):
>
> I also tried to connect the signal produced

This suggests that you may have initially tried something else; you may have damaged the Arduino or the input if you connected 12V directly.

I suggest that you test the Arduino inputs with 5V to see if they are working.

`:)`