Collective MPU

Introducing Collective Multi-Purpose Unit

We spent a bit more time on this than we would have liked to, but we were able to design a board that will cover a multitude of use cases. I’ll list the use cases, but direct instructions will be formulated later.

Set up as a bed presence or sofa presence sensor, you can attach up to 4 pressure sensors. If you’d also like to attach our wired motion sensors, you can do up to four with pressure using splits. (not covered here).
This gives you the ability to have more than enough coverage for a bed presence situation. Will you need that much? Probably not. But, it’s available and supported.

Set up as a garage door opener. You are able to control two garage doors with the CMPU which includes two wired contact sensors per door and two dry contact relays to control each door separately. Car presence is also possible, although it has not yet been fully tested. You would need one CMPU per double door for car presence. Cool stuff!

Just for @spelcheck , we also designed an application for a changing table. How convenient to connect a pressure sensor under the changing mat to trigger a light or baby friendly distractions when changing the little one. Middle of the night diaper dooties just got a bit easier when you don’t have to fumble with a light.

@markus 's favorite is water mains monitoring application. Turn the main valve on and off, report water pressure, flow, temperature. All of this is X’s 2. Wired leak sensors to forego the possibilities of a dead battery when it matters most. A great application to have for peace of mind.

You can also connect up to 4 motion sensors if you’re looking to master room presence. These sensors would work in tandem of each other to make sure your lights turn on. You could have them report as one sensor.

So, there are so many uses for this board that we haven’t thought of yet or haven’t done a kit for yet. Use case suggestions are welcomed, but when we begin sales, it’ll be very interesting to see what you make of these.

Now let’s get on to the specs:

  • Powered by 5v USB-C or micro USB depending on the ESP32 module used.
  • 4 digital only ESD protected 5v inputs.
  • 4 digital only ESD protected 5v outputs.
  • 3 analog inputs with 5.1k resistor pull-down*
  • 1 analog input with a selectable 5.1k resistor pull-down/pull-up/not connected*
  • 2 dry contact relays which have NO and NC (Normally Open/Normally Closed)
  • 4 x LED’s with the pins exposed can be used as separate 3.3v digital outputs. These are unsupported, but are there for the advanced user. The LED’s, can be used to indicate motion, or state. Rule driven. TBD
  • 4 x RJ12 connectors that will support CWPIR, CWCS, and CPS. And whatever else you can think to wire into them. Each has one digital input one digital output and an analog input/output*. It is also equipped with ground and 5v power. Total power draw is about 400 mA.
    *Analog input/output: output has limitations. This can also be digital input/output without ESD protection. Used under certain circumstances where ESD is not as important
  • The board is contained in a nice 45mm (1.76 in) x 143mm (5.62 in) x 29.5 mm (1.16 in) case to keep everything buttoned up.

The high precision resistors are not what you will find in your every day toolkit. +/- 0.1% accuracy

We are working on high resolution photos which will be posted in further updates in this thread.

We will post the specs for the CWPIR (Collective Wired PIR), CWCS (Collective Wired Contact Sensor), and CPS (Collective Pressure Sensor) in coming posts.


Very nice! Looks like a great companion to a DIY sensor I just set up here for testing.
I found a 24ghz radar 'human presence" sensor board that’s distance adjustable, wired it up to an esp running tasmota and it acts like a PIR that doesn’t time out just because you stopped moving


Hey, I want One of them :grinning:

1 Like

Forgive the ignorance is this something we will have to solder to? Or is this more of a plug and play kind of thing?

Former is bad for me, latter would be awesome.

For sure, so far it seems to be the ultimate solution to “room occupancy”
I’m planning on a full post once I get it sorted out and design a case to put it in, right now it’s just a couple boards & some wires hanging from the ceiling :joy: Not sure if the CMPU will have serial available to configure the sensor, but that’s just needed to set distance sensitivity. Supposedly these things even work behind walls, up to 9m range.

I ordered mine through mouser in the US.
They’re actually from a Chinese OEM originally, leapmmw, model HS2A43A. Looks like they have a few different models available on taobao apparently


It’s plug & play as a kit. Depending on which peripherals you want to connect to it. You can even connect the radar board if you wanted. Those will be defined over the next few days.


That’s lovely. Ty. Will these be released when core is or beforehand?

If before what do you recommend to control these ?

1 Like

The first ones will be connected to and ESP32 with Tasmota. They can run through node red. We will be offering an add-on Zigbee module that will be compatible with V1 CMPU down the road.

We will be releasing the CMPU soon. We’re finalizing a few things, but yah. Soon. I’ll post another announcement with details.


They are a lot of fun to mess with… I’ve had several set up around the house for a few months. But these are not the solution we all want sadly. They do go through walls, floors and ceilings, you can actually get up to about 15m range out of them, and as i discovered they can be triggered by a fly or sometimes even a gnat among other forms of interference that can trigger them. (i’m looking at you police speed trap that had my sensor going nuts all day)

There is a new sensor in development (not oh-la) Markus and I discussed that would be able to solve all the presence issues including number of people n a room position in the room and if they are standing sitting laying down etc. Maybe markus will have a few mins once he wakes up and can come give more details about it.

But back to the sensor your talking about, If you need to reduce the 360 detection a simple piece of aluminum foil will do the job of blocking detection in that direction. I’ve also pushed some of these chips as high as 7v without issue, however 1 of the 5 boards I had died out when the power went above 5.5v so YMMV.

If you get bored or are adventurous, you can stick one of these little suckers onto a servo and build an actual short range Doppler style system. I was actually using the doppler style setup at the back door for awhile to detect when someone was approaching and ring the doorbell automatically. I have another rigged up at the front door that is used to detect if any packages are left by the mail carrier.

There are a ton of fun sensors out there if you dont mind a bit of DIY… RF readers and chips can be a lot of fun.

Just do yourself a favor and don’t fall into the addressable Led decorating rabbit hole like i have :wink:


13 posts were split to a new topic: LED Rabbit Hole

Any update about mpu and/or other sensors?

It would be nice if the board could also supply 12v. This would allow the use of commercial sensors which have much better discrimination than the HA stuff.

Lol you guys need to quit teasing me and take my money!!



1 Like