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First LED project, help needed

Posted: Mon Dec 15, 2014 2:47 am
by The Midi Thief

I finally got around to order the last pieces to my LED kit. It doesn't quite work yet, so let's see if I can explain enough what I'm doing in order to get some help. I connected everything and what actually took me the longest was getting my Enttec DMX USB Pro up and running on my new machine.

Full view:
    1. I managed to get my LEDs (bright white, SMD 3528) to light up to what seems to be 50% brightness (at start they blink once at 100%). The LEDs do not respond to my DMX commands and they are lit when they shouldn't be.
    2. Shows the power supply and the DMX decoder connection.
    3+4. The power supply
    5. DMX Decoder, power connected.
    6. DMX Decocer, Channel 1 connected. I could potentially have switched the cables here since there is no way to know what the positive pole is. It's a water proof strip so the end of it is covered with white plastic. I just assumed that the red cable is positive.
    7. DMX settings in MadMapper
    8. Fixture setting sin MadMapper


    9. So I'm not exactly sure what is going on. I have a couple of things I'm unclear about. The setup of the Enttec DMX USB Pro was nothing but straight forward. I checked for old drivers and then used Enttec PRO Manager to install the new ones and update the firmware.
    10. I needed to use FTDI Driver control to shut the driver on and off. It seems it needs to be off when configuring the Enttec device but on when running Madmapper or else it won't show up in Madmapper. This could be a reason why it's not communicating with the DMX decoder?

I tried the "DMX Send" settings Enttecs PRO Manager and I got some reaction when 10th "FUN" switch on the Showjockey DMX decoder was in the upper position and I disabled/enabled the output in the PRO Manager, the LED strip blinked once in full bright intensity. Also, the Enttec device often blinks. According to the manual it means it is receiving data. However, if I turn off Madmapper it will still blink. I'm not sure what is going on there.

Can anyone spot anything I'm doing wrong?

Re: First LED project, help needed

Posted: Mon Dec 15, 2014 9:27 am
by .lov._

the positive/negative poles are important on the strip. You should be able to identify it, since that should be printed on the strip on every cut marks - check the attached picture. SMD3528 strips - usually - "negative controlled" which means they handle the PWM signal on the negative pole. So, the positive part should be attached to Vout, and the negative should be attached to CH1 on the DMX decoder.

In MadMapper, use "Pixel L" instead of "Pixel RGB", since you handle only 1 channel. (But that probably not the root of any issues).

The blinking you discovered over 50% of brightness probably happening because of power problems. How long is your strip? You always need to handle electronic things with strips like current, power, voltage drop. The SMD3528 strips power consumption is 4,8W/m (P). The voltage is 12V (U). From that, you can calculate the current (I) with this formula: I = P/U, so I = 4,8W/12V which is 0,4A/m. If you connected a 5m long strip, then the current will be (4,8W*5)/12V = 2A. With DMX decoders, you should now what is the max current it can handle per (DMX)channel - if that is not printed in the device, you should ask the manufacturer. I am not totally sure about this, but as far I remember the Showjockey DMX decoder can only handle 1A per (DMX) channel, so probably this is the root of the problem. You really should carry about this, because if you "send" more power/current to a device which it cannot handle, it can harm the device or even you! Disclaimer: I am not an electronic engineer, so I am could be wrong on this.

Regarding the problem you cannot control the strips. Best if you try to send from the Enttec Pro manager first to CH1. On the DMX decoder you should only enable "1" on the DIP switch. Make sure you connected the DMX out of the Enttec device. So, if you are able to control the strip from the Enttec PRO Manager, than the setup is correct, and that point you can try with MadMapper - in other words, first make sure everything is correct, then try to control that via MadMapper.

Generally, I would prefer Art-Net nodes instead of USB DMX dongles. Much less headache especially when you need more than one universe, no drivers needed, works everywhere, etc.

Hope this helps!

Re: First LED project, help needed

Posted: Tue Dec 16, 2014 3:13 am
by The Midi Thief
Thanks for great help (as always)! I have cut down the LED strip to a 30cm piece. The fist good 50 cm of the LED strip is unmarked but further up I found the positive/negative marks. I was using the positive pole for VOUT as I thought.

I first got it working in Modul8 but with the 1st dip switch in the wrong position. So then I figured out that the dip switches are upside down compared to the chart in MadMapper. So once I flipped all the switches on the Showjockey DMX Decoder, everything started to work properly. It's not all that easy with a Chinese device without manual :wink:

The Showjockey device is actually 3A per channel, so I should be able to control my whole roll of LED. But great to school me on math, I need it.

All right, time for a dicso nap. Pun intended. Peace out.

Re: First LED project, help needed

Posted: Tue Dec 16, 2014 8:33 am
by .lov._
Cool, glad you figured it out! BTW, the upside down DIP Switch is pretty common unfortunately, sorry for not mention it earlier! Anyway, happy blinking :wink:

Re: First LED project, help needed

Posted: Tue Dec 16, 2014 9:05 pm
by te-c
If you have any trouble with parts from showjockey they help you very fast and kind. They are really great!

Re: First LED project, help needed

Posted: Tue Feb 03, 2015 12:44 pm
by Chancedo1
Any specifications you can recommend if I would buy a new Mac Pro?
More Money to spend in CPU, GPU or RAM?