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Hi, I'm curious if a simple USB toTTL RS232/UART (converted by MAX485 to RS485 balanced line) works with DMX fixtures. If yes, which is the speed of serial port, parity and stop bit to use?

If then I want to use Freestyler which USB adapter I have to choose, and I have also to choose the COM port. Thank you for answers

With the converter to convert from TTL level to RS485 level (I thought that was 5V) and to a balanced interface, I think that would be possible to then control DMX fixtures with it.

Not sure if that is possible with FreeStyler, but my understanding is that there are cheap DMX interfaces on the market that are no less and no more than simple straight forward RS485 interfaces, you will need to select a com-port for those in FreeStyler as well. So you'll need to try out some devices to select in FreeStyler where you can select a COM port with it* (Try Eurolite Dmx Usb Pro-512). Or one where you can select your FTDI device directly, instead of the com-port. (I remember Entec Open DMX is a FTDI device, so try that)

Some more info to read on this subject:
https://arcattack.com/dmx-over-rs485-with-an-arduino (I know you're not going to use an Arduino, but still this might contain usefull info).
https://electronics.stackexchange.com/q ... n-the-prot

Having said that, in my experience these type of 'dumb' DMX interfaces completly rely on the hosts performance (host: FreeStyler, your PC, your USB bus) to be able to run the DMX data correctly, fast enough (250kbaud(??)) and in time. That is hard enough on itself and maybe harder on your self-build thing. So maybe you should prepare on a complete unusable build and lost time.

* If a comport is a option to select with a device, then that does NOT necessarily mean that its a 'dumb' DMX interface like yours is. It might be, it might not. If it doesn't work, try another.

thank you, sorry I opened another topic, I forgot about that. I had a chance to pass by that shop which sells it, and wondering if worth to buy. You said me yes, it should work, so I can use it to test some fixtures.
And I guess you're right about stability, probably the best way to address fixtures is to keep stability, avoid lags and so on, COM port is asyncronus and drivers may address it not good, it's better to have a processor which precisely generate dmx pattern and in the spare time receive (from USB) and update the pattern.
I'll read your articles )

Probably is not worth to buy it