Controlling devices in KNX network by phone App via Arduino

Good day friends,
I would like to start a project for controlling by phone App of my curtains motors which are presently controlled by KNX controllers and KNX switches in different rooms. Such ready devices exist but the cheapest I found cost above 550 EUR. Furthermore it has not skills for Alexa.

Well, I found in internet many topics how to connect Arduino to KNX network, record the telegrams from switches and then send same telegrams to the controllers for imitation of switches actions. The easiest and cheapest interface from serial to KNX bus is by Siemens KNX buss coupler. That is the easier part for me.

However I have no experience how to control Arduino from Phone App via WiFi or Zigbee. I also have not experience in programming for Android or iOS phones. May somebody help in that?

welcome to the forum!

It seems like this is a very difficult project considering your experience and knowhow.
You first need to understand and implement knx protocol, learn basics of rs485, ethernet, arduino language and android environment.
I suggest you start with something easier first and then move on to more complicated projects.

Hi Watcher, thanks for your answer.
Well , I do not think I am so green :grin:
I am Electrical and Electronic Engineer with 40 years experience. But I started to work recently especially with Arduino. RS422 and RS458 are my favorite protocols :grin:

I already did successfully one small project with Arduino Uno, INA226, ADS1115, LSM11 lambda sonde and K type thermo couple for display of O2 content and temperature of exhaust gases of pellet boiler. It works well but I did not published it yet. The code need some refining just to look more beautiful. Just received the aluminium box in which I intend to install it.

I found cheap KNX to UART interface by Siemens (25 EUR). Reading and recording of telegrams from my devices in KNX network is not a problem. Then I can send them in KNX network by Arduino and simulate pushing of curtain KNX switches. I do not want to pay 1000 EUR for ETAS software for finding group and individual addresses of my devices. It is enough to record the telegrams that they send and then simulate them by Arduino.

The missing part is controll of Arduino from app. I am still investigating but looks like Nano IoT can do it via Arduino cloud and Alexa skills. There are some complications with short and long press of the KNX buttons which I still did not find yet how to do it from Alexa. Unfortunately nobody wants to help. So I was forced to go for a deep research. But that Is good for ganing knowledge.

sorry if i underestimated your experience.
I am also an engineer but have no experience with knx. I use a different BMS protocol called hdlbus which is open. I managed to make my own devices based on custom arduino boards with this.