Java Libraries to Use for Serial and USB Devices

Development
21

It is intended to be used as integration plug together with PCHK software which translate bus level telegrams to text protocol handled by OH-LCN integration.

@Fischert implemented raw binding which was able to switch inputs/outputs over USB and without PCHK. Not sure where his work ended.

22

Hello Łukasz,

My LCN-binding is directly using the bus-protocol, but I never tested it with USB, only with serial port-communication.

I’m using it with Openhab 2.0 since a long time, open issue furthermore is the shutter-implementation. I tried to realize a time based position-automation, but the current implementation of that functionality is not good enough.

Best regards
Thomas

23

Thomas,

I haven’t yet started implementing OpenHAB. I have been waiting to make sure there is a reasonable chance of success before buying the Raspberry Pi and going down the rabbit hole.

Is your LCN-binding available to download once I decide to jump in?

Thanks,
Matt

24

Hi Matt,

I can send you the binding, that‘s no problem.

But as I mentioned:

  • I‘ m using the serial connector (LCN-PK), I never tested it with the USB Connector (LCN- PKU)
  • I developed the binding some time again - for Openhab-2.0. I don‘t know if something has to be adapted for 2.5.

Regards
Thomas

25

The manufacturer of LCN strongly discourages accessing the LCN bus directly via serial connection.

Using LCN-PCHK or LCN-PKE is the recommended way. These softwares contain important timings like appropriate inter-frame gaps and also rate-limits in case a third-party software like OH runs crazy to guarentee a still functioning bus. Accessing the bus directly has impact to collision detection and can therefore cause lost frames.

Just for clarification, there is an LCN binding for openHAB 2 & 3, which is part of the official distribution.

Disclaimer: I’m a former employee/developer of the manufacturer company and I’m the author of above binding.

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26

Technically speaking this is what ebus binding does thanks to https://github.com/csowada/ebus. @csowada implemented bus collision detection, handling of escape symbols and all other low level stuff. All possible with serial port.
There are other solutions such domiq mentioned above, which is attached directly to bus. Without the need for a connection license. Things you mention have impact on the complexity of integration thus also the costs of its development to achieve stable work over time.