KNX with micropython

[dschwert]

Yes, I want to use and ESP8266 and directly read/write to the bus.

What dou you mean with "direct"? You always need a physical layer interface. The easiest is a TPUART like NCN5120.
Or do you plan for something like selfbus?

[bmx]

@henfri is writing about ESP8266 so he might want to send and receive via WiFi to KNX on an IP Router or knxd operated Raspi...

[dschwert]

Well, IMHO that's about the opposite of "direct".

I have never used KNXd. Isn't it backwards compatible to eibd?

Using a normal IP Router is probably not the most clever idea, as these usually have a very limited number of concurrent connections.
When I started with KNX five years ago, I had the impression that in the DIY community there were more eibds than IP routers.

[henfri]

Hello,

yes, with directly connecting to KNX I mean without and KNXd/eibd via multicast (port 3671). This is only requires a KNX Router(*), nothing else. Every ESP8266 in the same network can -without further hardware- communicate with KNX this way.

When communicating via TCP/port 6720, one needs a knxd/eibd. This is what your second library does, isn't it?

When I started with KNX five years ago, I had the impression that in the DIY community there were more eibds than IP routers.

I do have one today. But I don't want to rely on it. Maybe in 10 years I prefer not being a sysadmin of my home anymore and buy a true knx-router. That's why I am hesitant of using the communication.

What dou you mean with "direct"? You always need a physical layer interface.

Yes, and that would be Wifi -builtin into the ESP.

Well, IMHO that's about the opposite of "direct".

What? Let's be precise:
3671/multicast is direct and KNX standard
6720/TCP is not
Do you agree?

I have never used KNXd. Isn't it backwards compatible to eibd?

I know of nothing that does not work with KNXd but did work with eibd. But the confguration is different.

Using a normal IP Router is probably not the most clever idea, as these usually have a very limited number of concurrent connections.

You need to distinguish:
There are "KNX/IP Routers" (=routing=multicast) and "KNX/IP Interfaces" (=tunneling=unicast). Some Routers also offer tunnels as well thus acting as interface.

Port 3671 ist multicast and has no limitation of connections.

(*)If -and only if- no KNX router (but just a KNX IP-Interface or an KNX-Serial Interface or whatever) is available, one can turn this into a KNX router with knxd/eibd

[dschwert]

When communicating via TCP/port 6720, one needs a knxd/eibd. This is what your second library does, isn't it?

Correct.

Personally, I don't find the Wifi approach very attractive. I would not want to have more than one or two devices connected via Wifi. E.g. I would not want to replace my 1-Wire and window contact interfaces with ESP modules and their power supplies. For more complex things, I'm fine with running Python on the Raspberry as there I have the usual infrastructure including debugger.

When looking at the libraries you have listed, it should be doable to port one to Micropython or have a look at them to learn for your own implementation. As I don't have an ESP, I don't know whether uasyncio supports networking and could directly replace asyncio.

Regards,
Dietmar