KNX connector Implementation (usermod)

[Alex0176]

Is your feature request related to a problem? Please describe.
The featurerequest is primary for use WLED via KNX Bus or better the Presets for KNX Group Addresses.

Describe the solution you'd like
There is a git project for use KNX and can be used for set the KNX Address and send and receive data from/to KNX Bus with a ,,Bus Koppler" (bus coupling unit, i.e. a bus connector). In this Video (german) you see whats needed for KNX and the wireing:
https://www.youtube.com/watch?v=KtBNI-xF23w

the KNX lib can be downloaded here:
https://knx-user-forum.de/filedata/fetch?id=1549797

• So you can select presets via Group Adresses
• Send % values via KNX (for example for garage doors or water filled or temp

Describe alternatives you've considered
In WLED is needed to:

• Implement the KNX Lib.
• Add a enable KNX with the KNX Adress (this must be the same like a Dummy device in ETS)
• Add a possibility for Group Addresses for sending and receiving the values.

Values:
Send to KNX: actual preset, on/off WLED (for Powersupply)
Receive from KNX: set preset, set % value (for special effects)

Additional context
Add any other context or screenshots about the feature request here.

Thank you for your ideas for making WLED better!

Maintainer update
KNX seems to be a standard bus for industrial sensors and actuator (similar to I2C, but bigger, longer cables, etc) for building automation systems. Ready made libraries to handle the low-level communication are availeable.

According to wikipedia https://en.m.wikipedia.org/wiki/KNX

KNX devices are commonly connected by a twisted pair bus and can be modified from a controller.

KNX is not based on a specific hardware platform and a network can be controlled by anything from an 8-bit microcontroller to a PC, according to the demands of a particular building. The most common form of installation is over twisted pair medium.

A KNX installation always consists of a set of devices connected to the bus or network. Device models vary according to node roles, capabilities, management features and configuration modes, and are all laid down in the profiles. There are also general-purpose device models, such as for bus coupling units (BCUs) or bus interface modules (BIMs).

Devices may be identified and subsequently accessed throughout the network either by their individual address, or by their unique serial number, depending on the configuration mode. (Unique serial numbers are allocated by the KNX Association Certification Department.) Devices can also disclose both a manufacturer specific reference and functional (manufacturer independent) information when queried.

KNX can link up to 57,375 devices using 16-bit addresses.

[Aircoookie]

This is a good idea and would be best implemented as a WLED usermod by a knowledgable user with a KNX system :)

[Alex0176]

i think the parts todo: ( i can read C/C++, but i have no knowlage in this)

• add knx lib
• add on init file (i dont know where to find) if knx is enabled set the correct physical adress to the knx lib.

if (knx ==true) {
    KnxTpUart knx(&Serial1, "x.x.x"); // "x.x.x" should be the stored physical adress in cfg.cpp
    Serial1.begin(19200, SERIAL_8E1)
    knx.uartReset();
}

• add the information into the preset.cpp (for save/load the settings)
• add enable knx and physical adress to cfg.cpp
• modify the html templates
• make a thread loop for the knx part and fire up events on the correct lines of code to knx, if its enabled.
  for example in present.cpp (hopefully thats the correct point)

... applyPresent(.....)
if(knx ==true && presentGroupAdd!=null){

bool success = knx.groupWriteBool("x/x/x", index);
.....

in the settings.html add the line:
<form action="/settings/knx"><button type="submit">KNX Setup</button></form>

add a new settings_knx.html file (only for the enable and physical adress or with group address settings to write or read)
it depends if everything with knx should be on one point. I dont know how to read out the existing presents, so i can not make a example.

The html_settings.h have to be autogenerated again.

[Alex0176]

Today i had 2 hours time and check out the usermod v2 example and i make a few things, but i dont know how i can add config fields to define the group address directly at the presents in the webinterface (for now i make a possibility of 50 presets hardcorded and i dont know how to compile the staff.

i get everytime a missing
#include <KnxTpUart.h>
^
compilation terminated.

In Visual Studio with PlatformIO

Can anyone compile it for me or help me with my questions?

extract this to the usermod directory:

compile options: -D USERMOD_KNX

in the usermods_list.cpp you have to add:

#ifdef USERMOD_KNX
include "../usermods/KNX-Presents/knx-presents.h"
#endif
:
KNX-Presents.zip

void registerUsermods()
{
#ifdef USERMOD_KNX
usermods.add(new KNXPreset());
#endif
:
:

[Alex0176]

i got now a link error, but i'am not able to fix this. i think there is a issue with casting the serial port to a stream.

Can anyone help me in this case?

/../../../xtensa-lx106-elf/bin/ld.exe: .pio\build\d1_mini\src\usermods_list.cpp.o: in function `_GLOBAL__sub_I_physicalAddress':
usermods_list.cpp:(.text.startup._GLOBAL__sub_I_physicalAddress+0x2b): undefined reference to `KnxTpUart::KnxTpUart(Stream*, String)'
collect2.exe: error: ld returned 1 exit status
*** [.pio\build\d1_mini\firmware.elf] Error 1

KNX-Presents-a0.0.2.zip

[blazoncek]

Please use WLED forum or Discord for help and support questions.

[h1ghb1rd]

@Alex0176 Have you made any progress on this?

[Alex0176]

@h1ghb1rd Have you made any progress one this?

i dont know why it does not compile ... and noone like to help me in this case.

[softhack007]

Today i had 2 hours time and check out the usermod v2 example and i make a few things

Welcome to the world of WLED development :-)
Not to spread frustration, but I'd encourage you to spend more time on the task. 2 hours is surely to little time to even understanding the basic.

---

#include <KnxTpUart.h>
^
compilation terminated.
undefined reference to `KnxTpUart::KnxTpUart(Stream*, String)'
collect2.exe: error: ld returned 1 exit status

This looks like platformIO cannot find a library that provides KnxTpUart.h. which library do you want to use?

This library looks similar to what is missing: https://github.com/majuss/KnxTpUart

To use it, add a line majuss/KnxTpUart to global lib_deps
https://github.com/Aircoookie/WLED/blob/74156b7ed8a1449ed459baeb7934debb53a19665/platformio.ini#L149-L160

---

add the information into the preset.cpp (for save/load the settings)
add enable knx and physical adress to cfg.cpp
modify the html templates

Actually you don't need to fiddle with set.cpp + cfg.cpp and html templates, if you want to add your own usermod settings section. This can be done from inside the usermod, using the standard JSON API.

https://github.com/Aircoookie/WLED/blob/74156b7ed8a1449ed459baeb7934debb53a19665/usermods/EXAMPLE_v2/usermod_v2_example.h#L187-L197

If you need a full example, take a look at the boblight usermod
https://github.com/Aircoookie/WLED/blob/74156b7ed8a1449ed459baeb7934debb53a19665/usermods/boblight/boblight.h#L307-L351

[Alex0176]

KnxTpUart.h

Hi, the libs are included in the ZIP File, and i dont get this kind of compile error.

I get in the Version KNX-Presents-a0.0.2.zip the error /../../../xtensa-lx106-elf/bin/ld.exe: .pio\build\d1_mini\src\usermods_list.cpp.o: in function _GLOBAL__sub_I_physicalAddress':
usermods_list.cpp:(.text.startup._GLOBAL__sub_I_physicalAddress+0x2b): undefined reference to KnxTpUart::KnxTpUart(Stream*, String)' collect2.exe: error: ld returned 1 exit status *** [.pio\build\d1_mini\firmware.elf] Error 1

So its not a libary problem, more a linker or add cpp problem. i dont know - i am not a c programmer, so its hard for me to figure out whats exacly the problem right now.

[softhack007]

So its not a libary problem, more a linker or add cpp problem. i dont know - i am not a c programmer,

Actually it is a library problem, as the linker does not find the library where the class KnxTpUart is implemented.

This typically happens in platformIO if you manage to feed it with a header file, but did not use the proper way of importing an external library into platformIO. The usual way to do so, is by using lib_deps and pointing to a github repository that provides the library. Please try to understand my above answer fully, as I already explained how it might be solved.

[Alex0176]

i dont know how i can configure this - so i hope anyone other with C knowlege can work on it. i can tast and help with the logic