Can I connect to a DALI network as a master node using an Arduino? I have googled a lot, and mostly every website you can link me I have already explored, some are outdated and don't work, others aren't clear in their documentation, and use equipment too expensive to run the risk of buying it and it not working.

https://github.com/edinburghhacklab/dali

https://github.com/sde1000/python-dali

https://github.com/krzychb/DimSwitch/blob/master/extras/pictures/PHILIPS-HF-REGULATOR-TOUCH-a-DALI%2018-58w-T8-%201-a-2-LAMPS.pdf

http://microcontrollershop.com/product_info.php?products_id=5384

Moreover, like any free protocol, you have to pay to access the DALI standard.

What can I do to control a network of connected DALI dimmable ballasts?
I have made a simple DALI controller with Arduino Nano. Maybe it will be useful for you. Look here: Simple DALI Controller