I need two contacts .... for a Catflap . Idea?

if ( cats > 1 ) || ( wild_animal ) {
	problem.state = huge
} else {

I’ve seen commercial cat doors that read the rfid chip many pet owners embed under the skin of the pet. I bet someone has posted a “look what I built” DIY article on HackADay or the like. :slight_smile: I don’t know how easy it is to read them with DIY readers though so a tag on a collar might be an option. Though anyone with cats will know that it isn’t always that easy to keep a collar on a cat.

But back to the OP, @Topsurfer, how are you using the two contacts?

I would imagine that any of the door/window sensors would work. If you have power nearby or are up for building a complete DIY system with a case, wiring up reed senors to ESP8266s or RPis is about as easy as it gets for the DIY front.

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If going the DIY and no power close by, use 22 gauge twisted pair (or two pair if needing two sensors) shielded wire. Assuming no huge interference you can have the reed switch and Esp/RPI located on different ends of the home. I use a similar setup with a reed switch and the only modification needed was to add a small decoupling capacitor to prevent false triggers.

Probably what I should have done, but I can say that I get good connection/reception on two reed sensors on a run of about 40 feet with speaker wire (it’s what I had). The garage controller is on one side of the garage and the sensors are on the other, 12 foot ceilings with a bump out in the ceiling I needed to go around makes for a pretty long run.

I don’t have a capacitor but I do have a resistor. No false triggers so far.

The finished product. Expensive.
The flap reads common ID chips implanted in the animal for access control.
(I have the cheaper dumb non-communicating version to keep out the local Tom, our two queens use it reliably, battery life is good)

This is the smarter version, which requires a separate “hub” to talk over WiFi to the app.
App allows individual cat control, scheduled in or out times, and reporting.
I don’t know of an API.


My guess is the flap uses zwave or similar, hence the hub. I wonder if it is hackable to avoid the hub.

You could add contacts to the dumb version, to determine in / out, but I can’t see any ready means to get at the ID of the “user”.
You ‘program’ it by by pressing a button and, uh, “introducing” the cat to it. That’s fun, if a little bloody for the instructor.

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[joking] quick, hide this post with this Cat Flat Connect… my wife will read the forum and I will be in trouble… I can already hear her say “this is a real Home Automation device that you should have installed… not the other DIY crap” ! :slight_smile: [/joking]

Nice, but too expensive…

I have build in two contacts inside the Catflap axis, so if the Catflap open more than 60 degress in direction outside contact A is closed, when Catflap open more than 60 degress in direction inside contact B is closed.

And yes, I know the RFID solution, but actual not a topic: I will use my “unsecure” solution.

I check the ZD2102, there is the option to use a second contact, but I on a german page I read the second contact will not trigger a second event, use the same “way” as the first contact (parallel switch).
But I need two different signals …
Or is the info wrong? Here is a PDF, maybe you can read is “correctly”. (Update: Link fixed, thx)

I have a Devolo Homecontact, which has a Alarm contact (tamper) and brightness.
From Alarm switch I never see a entry in log (Devolo LED goes red), and the brightness is send not very often (I thought I can use the brightness sensor as signal for the 2nd contact, connect a resistor to the brightness sensor (=verby bright=contact 2 is closed) …) (Hint: DoorContact is send immediately).

So if you you know a “normal” door contact which send quickly Alarm info I can try to use this contact outside as 2nd contact.
Or when the brightness is send in real time I can also try to use this modefied “signal” …

From what I understand from this discussion here: [SOLVED] Vision Door/Windows sensor zd2102 open/close and tamper are not triggered to different events - #106 by 5iver is that:

The second (external) contact on the specific device (WADWAZ-1) has a separate sensor_binary channel and it should trigger independently of the main sensor_door channel.

You can ask @5iver and/or @Doc about this since they have been using this specific setup with 2 contacts.

Ps: Your pdf is not uploaded

When using the WADWAZ-1 as a door sensor, I configure the Item to use the alarm_entry channel. When using the WADWAZ-1 as a leak sensor (using the external switch), I configure the Item to use the sensor_binary channel. One unfortunate functional gap is that the sensor_binary channel needs to be linked to the BASIC CC, but @chris decided to remove polling for the BASIC CC, so the channel does not get polled. :frowning_face: This “feature” also rendered the scene_number channel useless in most (all?) Leviton dimmers and switches. :sob:

I only have WADWAZ-1s, but I believe that all of the devices in the table Angelos linked to in the second post can use external switches connected to terminal posts inside the device with a knockout in the cover. They are all the some device, except some have zwave plus, so the behavior of the external switch could be different. I only added the channel to the WADWAZ-1, so if you can verify that your device has the terminal posts, then add the channel in the db. If you have trouble, just let me know which device, and I will add it for you.

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Do I missunderstood it, or is the result that the status from second contact will not be send in realtime to openHAB? At the end I need two contacts which are sending every change in real time (as the original door contacts are doing)

The device will report the external switch in realtime through the sensor_binary channel, but the binding will not poll this channel. This really shouldn’t effect your application though.

The simplest (and easiest) solution would be a ESP8266 with two contacts running Tasmota. If you configure the contacts as switches you will get a near instantaneous MQTT message to openHAB.

ESP8266 will/can be a solution, but no experiance how to program these (naked) boards.

What about the sonoff basic parts (and yes, they have inside EPS8266 I think), as I saw now they also have 4 GPIO’s inside.
I also flash my first to Tasmota including MQTT …

Can I use two of these GPIOs for my catflap-contacts, and two to connect two LED’s (status, if cat is in (green) or out (red)) ?
(I still have these LED’s on my Raspberry, connected on two GPIO’s there)

I recommend buying an ESP8266 development board, it comes with header pins, resistors, diodes,etc… installed on the board. A USB cable is used to program and power the unit.

If you’ve flashed tasmota to a Sonoff device, then flashing firmware to an ESP is done the same way, except you use the USB cable. Personally, I like to use Esp Easy firmware on all my ESP devices but you can use what you like.

I have a mixture of Sonoffs and ESP8266 IoT relays. The sonoffs are good but, increasingly, you need to solder a PCB header to the board whereas a Nodemcu/Wemos board can be programmed and powered by USB. You could probably use a Sonoff Dual for your application

I only have 230V in the near, so USB power will be not an advantage …

But still unshure if the four provided GPIO’s from the “sonoff basic” can be used for this case:
2x as output to connect two LEDs
2x as input for the two contacts

(the relay function will be gone, no problem. And connect cable on the plumb or circuit board will also not a problem!)


Search google, you may find a tutorial for hacking the Sonoff to add addition GPIO pins.

Now I order the Device WADWAZ-1. In germany it’ s selled i.e. from Schwaiger, called “ZHS09” (Type-ID: 2001/0106). This is also labeled as a zwave PLUS -device.

Scott give me (great!) support here to bring this device to work with two contacts.
I will provide a short “how to” if we finished, hopefully soon and successfully.

A little more detail… the Vision ZD2102-5 does have contacts for an external switch. The manual provides the details. After some testing, we’ll get the device db updated.

After few testings it seems that the external contact from the “Schwaiger ZHS09” is connected to the reed contacts! Also Scott is thinking now so.

So not independently as it looks! So not usable :frowning:
The Schwaiger is a “zwave plus” device, and can it be that all zwave plus devices has no second contact?
Maybe one can give me a hint what battery powered device (which is available in germany, ie. amazon.de) has a “real” second contact.