Build Arduino DALI controller to wotk with Osram QTi DALI 4x14/24 DIM


We have some QTi DALI 4x14/24 DIM balasts and we want to build a DALI controller so we can program sequences with arduino to control the flurecent lights (decoration).

We have been fiddling with it and looking into the web to find schematics to do so with Arduino.

The main idea is to create a webinterface that controls the circuit via Arduino using the following library edinburghhacklab/dali. We think the Arduino circuit should control a 16V circuit in order to control the DALI balasts.

We have found this topic on the forum and there is a user saying:

NikWing: and another posting

I kicked the dali click board away and got me a small lab PSU, a 20 ohms resistor, an optocoupler and a transistor and connected all of that to the dali ballast

So is it possible to do it like this? What is the use for the transistor?

Thanks in advance!