I have created a Multi sensor PIR including a dallas temp measurement and LDR light measurment. For the PIR I wanted to use the Original PIR but it got "destroyed" during my investigation. The Pir runs on two AAA as I have removed the voltage regulator on my arduino pro mini.

It is unfortunately not a full How-To yet. But basically the IKEA PIR is ready for operation.

• The PIR Runs on 3 Volt. There is a power regulator (U1). I am going to keep the 3 AAA batteries so I keep the regulator on the board.

• I have removed the resistor (R17) and attached two wires to both the Original ends on the board. The one closest to the BISS0001 is your PIR signal. 3V when high and 0V for low. The other wire can be used to control the lights on the board. The wire is connected to the Q1 NPN transistor. Basically 3V high is on and 0V is off. But maybe you will also be able to dim the lights.

• You also need to remove Resistor R11. The Original value is about 620 K and this will result in 30 seconds of ON after triggering. I have replaced it with 100 K and now it is about 5 seconds, a further reduction whill shorten this time lineair. So 10K = 0,5 sec. The PIR itself is retriggered.

• With resistor R10 is controlling the time that the PIR cannot be triggered after a trigger. It is now approx 10K = 0,5 sec. So no need to change.

• You need also to remove the photodiode on the front. Otherwise the PIR is only triggered when it is dark.

• The powerconsumption of the PIR when not triggered is approx. 60 uA and when triggered 160 uA. So this is about the same as the standard PIR's. When the lights are activated the consumption is about 36 mA.

• The PIR (without the hood) is quite sensitive. Even the slightest movement is already triggering the PIR.

After I have bought some new one I will try to make a how to....

@scalz @tbowmo Looking forward to see you results! Now that my prototype is finished of course I am going to buy some more as well. Here "only" €4,99 for an item

I now have a fresh supply of Molgan to be modified. And I will post my modification of the existing board soon. Status I can now use the input of the existing PIR signal. And I have discovered that by sending out a high or low on one of the arduino pins I can switch the existing LED on / off. Of course I can use a relay function to control but as it is running on batteries the sensor has to sleep. I was thinking of sending out a parameter (true / false) which enables the sensor to activate the LED on a trigger of the PIR. How could I send over this parameter? Any (creative) idea's as the sensor is sleeping most of the time?

Now I am thinking of it, could it be possible that such a value is read by the sensor when the sensor is getting out of the sleep function.

@tomkxy You can change the sensitivity of the PIR. You have to change the value or R15. See here for a datasheet of the BISS001
But I do not know whether you should increase or decrease it...?
If you did not modify your PIR then the PIR will stay high for 30 SEC. What is the period between the false triggers?
Could it have to do with powering your sensebender from the powersource within the PIR and not directly from the battery?

@dpcr Nice adjustment of your Original code. Based on your Original version I have started coding as well as I like the simpleness of just adding a sensor to the meter without taking care of the direct position.
My current code can be found at github via the following link:

https://github.com/rspaargaren/Read_Gasmeter/blob/Workinprogress/Read_Gasmeter.ino

Basic differences are:

• I have removed the fram reference but this could be added again if you use it.
• I have added a different setup sequence for fixing the top and bottom. In my case it waits until four changes in direction have occured. So no direct gas flow have to flow after a restart.
• The number of pulses between a change in direction is fixed independent of a change in top or bottom. So in my case every half a cycle will give ten pulses and a full cycle 20 pulses.
• The results are submitted to the gateway after a intervall but also after half a cycle.
• The top and bottom is checked after each cycle. So in case of major difference the interval is changed.
• During normal run, the reading of the y value is executed within the loop. So basically the arduino has time to do some other stuff as well in between the readings.

The code is currently working but requires some clean up. Also I would like to make an option to store the values at the gateway and maybe change the hardware to an ESP version so I can have multiple ways of output. Like MQTT.
This is the current output in Grafana:

I am migrating step by step from pimatic to Hass. I still think pimatic is a lot easier to setup and to make rules, etc.. But the community behind hass is big and the ammount of items which can be controlled is huge. The mysensor part is not optimal I am using the MQTT gateway and hope some further development is made.

@ricmail85 @Yveaux basically mine was shortcut by testing Some connection which I should not have Done....

@ricmail85 hi iT has been a while ago but as far as I recollect I had the same problem with one of my sensors ...

In normal situation the sensors gives a high signal for approx 30 sec.

In the bricked PIR I have replace the pir board by a cheap and modified pir from Ali.

@pihome Hi i am powering it with adapter. So no batteries used.

@Ed1500 The amplitude is quite simple it is just measuring the (max) top and (min)bottom if the direction of your signal changes.This is quite consistent during the readings and if due to temperaturen or whatever cause it is changing the max and min are adjusted. However the period / frequency of the curve is not consistent as this is directly related to the consumption.
I think the linear approach to the curve is already quite accurate. But if you have a better routine in mind I love to hear. Basically I just have to adjust the array in which the different steps are calculated.

I like the idee of having a dedicated attiny as I know from my sketch that in case of high volume the changes is the y are quite fast and the is (almost) no time to communicate with the gateway etc.

@dpcr the more steps you choose of course the more accurate it gets. At this moment I have divided the Total cycle in 20 steps. I have made this a parameter in my code.

@Ed1500 The magnetometer is picking up a change in the magnetic field. Normally the sensor itself is moving and so changes in x,y and z etc can be detected. In case of the gas meter the sensor is stationary but the change in magnetic field due to the rotating magnet on the dial is detected. This will give you a snow wave.

I presume In case no magnet still small changes can be detected due to rotating parts within the meter.

@zboblamont That is a quite nice price indeed.

@jumping No I do not. Basically I use my gateway to store and retrieve the pulse value.

@dpcr Hi, I need to recalibrate to see if the reading is still OK. Somewhere during a total reset I have lost track. But it is on my to do list to get everything up and running again.
As far as I could recollect an overshoot had no influence on my code as the number of pulses for a total cycle is consistent within my code.

On the Y reading from the sensor I do have a running average smoothing.
Basically every cycle is splitted into rising and falling part. Each splitted into a fixed number of steps. Based on the current reading of y the number of pulses is calculated within that step. So the amount of pulses within a rise or fall can never be more than the number of steps within that cycle.

I am thinking of making the code more simple and only give a pulse on the changes and maybe one in the middle. That would give me about 4 pulses per cycle.