Best posts made by jimmyjames

I have been playing around with these Fl5150 with success. I've been using the DAC on ESP32 and an Op Amp and I can dim it up and down with an arduino sketch and also with home assistant via ESPhome. It's a work in progress at the moment but here is the Schematic https://easyeda.com/james_6977/fl5150-dimming-with-dac
I intend on improving it to a more usable and safer point. In this version only 1 dimmer will work properly(it works good though, will turn off and you have good control over the level) if you try and use both there is some interference that makes them both not work properly.
I've ordered a I2C DAC which would need a Op amp as it can sink to ground unlike the ESP32 DAC (I think??) and a I2C digital isolator so that I can try separating the 240v from the MCU and then 1 x MCU could potential control a number of dimmers, in my case 4 inside a control box I've made up.

The Dual Op amp in this board I've made up, sinks the current that the FL5150 puts out of the DIM control pin to ground and ensures that the voltage at the DIM control pin remains at what ever the ESP32 DAC is producing on GPIO 26 and feeding into the OPamp non-inverting input.

@boozz Basically it comes down to the final application, and was just letting others know that, it is important to consider what will go where, how it will get used.
With the schematic in it current form, 240v and the 5v side is not galvanically isolated, which is ok, as long as everything remains inside an insulated or earthed enclosure, and only 240v wires go in and out. That means you should not add external sensors or switches to the ESP32, which although they will work will be referenced to neutral or possibly line, which could create a potential hazard. I was considering using a I2c isolator to keep the ESP32 galvanically isolated from the FL5150 dimmer circuit, I have ordered the parts to try it too, the only downside is then you need a power supply for the ESP32 and isolated one and another power supply for the I2C isolator on the FL5150dimmer side as it uses upto 6mA 5vdc and the DAC use 1mA so that is inconvenient.
I have a video of the lasted dimmer i've tried: https://youtu.be/bXHvo86CJp4