Adaptability of DALI Click Board for DALI Power Supply 18V DC, 250mA
There shouldn't be any reason for damage to occur if this is connected correctly. The DALI PSU is current limited so it will not be damaged even if the DALI line is short circuited. The DALI Click board is bipolar due to the bridge rectifier so polarity doesn't matter. The DALI TX and RX signals are pulled to Vcc on the DALI Click board so you need to connect the Vcc of that to your STM32 board Vcc. The opto coupler current maximum shouldn't come into it. The receiver side opto LED is in a current limiting circuit that has been designed for the DALI supply voltage range. The transmitter side opto transistor won't see the DALI PSU current because it will flow through the FET when it is on, not through the opto transistor.