I'm having a problem with this circuit. I am trying to get an LED wash light circuit to be remote controlled via DMX512. The problem is, after I found the circuit for the RS485 (which will deliver the DMX signal to my LED circuit) my professor told me that there's no time to make it and that I should just buy it. I couldn't find a descent one to buy. I am also not sure if I should connect the LEDs with parallels or using a darlington pair? ! I have attached the circuitry for the RS485. Also, the options I have to connect the LEDs, not even sure which Microcontroller is the best for them. Any help? It's also 5 - 9 LEDs.
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I really need the help on the best method to design the LED circuit, since my previous one was rejected by my advisor. Also, can I please get a website link that I can buy a read RS485 from? any help with the LED circuit would be appreciated.

 

Hello,

It looks like you got the schematic from this page:
http://www.hoelscher-hi.de/hendrik/english/led.htm
On the bottom of the page there are some ideas how to connect the leds.

Bertus

 

If you want to make something, I would suggest a PIC. Code to receive DMX can be found here:-
http://www.qsl.net/n5tle/dmx2avc.asm
You could adapt this code.

Couple the DMX (which is RS485) to the PIC like this:-
http://www.qsl.net/n5tle/dmx2avc.pdf
Look at the connections around IC2.

I would control the brightness of the LEDs using PWM. Fairly easy to do in PIC software. Some PICs have a limited number of PWM peripherals built in.

The simple way to drive the LED would be a logic-level MOSFET and a series current limiting resistor to control LED current.

 

Bertus, Yes I got it from there. Unfortunately I was asked not to do it, and to buy a ready RS485 (do you have any idea where to buy a good one?). I have looked at the bottom of whereas the 3 circuits, I just couldn't figure which was suited until I first find the new RS458 I'm about to buy. Thank you for your help.

JDT , I will defiantly have a look at those sites. I really appreciate your help. Thanks a million.

 

Hello,

DMX is a communication standard that uses RS485 to transport the data.
You will need to decode the data to drive the leds.
Do you want to have a ready made system for that or do you want to make a system yourself?

The page I gave you before is for making the system yourself.

Here are some shops where you can buy ready made system for some big bucks:
http://www.showcasetechnologies.co.uk/
http://www.ledridge.co.uk/shop/category/rgb-controllers/rgb-flexi-ribbon-dmx-reciever/

Bertus

 

Will this help ?

http://www.amazon.com/Velleman-DMX-Controlled-Relay-Kit/dp/B001IRQHKG