I want to controle several lamps via DMX. They need to be powered with 24V and the DMX signal also has to be 24V.
So i need to boost the 5V coming out of the Arduino somehow. I thought about using a N-MOSFET, but i dont know which one i should choose or whether there is a better solution. What do you guys think i should do?
the DMX signal also has to be 24V
Are you sure about this?
Yes any logic level FET will do.
DMX is RS485. 24V is not a normal part of that. It sounds to me it looks like you have lights that work similar to some scrollers. They have a 4 wire feed:
V+ for power
The DMX signals stay the same 2.5 V level.
Yes I'm pretty sure it needs 24V.
I want to control Color Kinetics (iColor Cove LT).
Somebody did something similar before: http://mit.edu/loganw/www/color_kinetics.html.
The author and me had some email contact where he also stated that the devices need 24V on the data port but I don't exactly know which lights he used.
The iColor Cove LT has 3 pins.
Do I have to consider anything special before buying MOSFETs?
There is nothing in those links that says the signal has to be 24V just the power supply.
It does say it uses the Color Kinetics full line of controllers, DMX 512 (RS485) compatible when
using Color Kinetics power/data supply, and Stand Alone.
So the question is do you have this controller? Or are you trying to make a DMX shield or exactly what are you trying to do?
i don't have on of these controllers. I want to create a board which controls the fixtures.
The site says:
To control Color Kinetics fixtures, I wrote a simple application for the Arduino microntroller to send DMX512 style serial messages, and a transistor connected to +24V to increase the voltages to levels accepted by the fixtures.
He confirmed that the data port needs 24VDC via email too but as i said i don't exactly know which fixtures he has. i asked him a few hours ago but he didn't reply yet. I could try out both voltages but i don't have an applicable power supply yet. Since shipping from electronic stores is a bit expensive here in germany i want to order an applicable MOSFET too so i don't have to order a second time :).
So do I have to consider anything special before buying MOSFETs?
Thanks for your help
Look at page 5 of the data sheet. They show the pinout of the 3 pin connector. It is NOT running DMX as it is understood by most people in the industry. It requires a controller that takes the balanced DMX/RS485 signal and unbalances it. The controller is also the PSU. The next step is to get a controller/PSU or figure out what is happening on the data line. It could be any thing from a 3.3V/5V TTL/CMOS signal voltage with the DMX packets intact to some sort of reformatted data packet at some odd voltage.
I could be wrong but I doubt the data signal is 24V, other wise they would get better distance.