Sign up Calendar Latest Topics
 
 
 


Reply
  Author   Comment  
timoldenb

Registered:
Posts: 11
Reply with quote  #1 
Hello from Switzerland..

I recently moved to another place and during the clean up, I found some old PCBs ..
The first was a design for a friend who loves LED bars and wanted to use some cheap
ones on stage with DMX. (Front side, left: MCU, crystal, DMX transceiver and voltage
regulator, even power supply connector and rectifier for "dumbest user" usage. Bottom
side, right: the FET to drive two LED bars, RGB with common ground. I think the "common
V+" version is somewhere around here too..)

So in short terms: This PCB has a dip switch for DMX address, and the original software
I wrote controls two LED bars, with 4-channel-mode. LED 1 -> dmx_address and LED 2 ->
dmx_address + 4

dmx_int_640.png 

And I had a couple of these laying around:

ftdi_640.png 

Some FTDI-type USB to serial (in fact: all important FTDI-pins are available on the header) adapter.


So I soldered the parts, put all things together, wrote some new firmware for the first PCB and this
is what came out of a two to three hour work:

test_1_640.png 

Top right: The FTDI Interface. Plus SN75176 to convert the 5V serial signal from the FTDI to
RS485 / DMX signal.

Top left: The assembled DMX-Led-Interface. In fact, it was for those rather dumb, voltage controlled
RGB-Bars, but I had two pins for status LED on the board, so I used one of them to pin-toggle the
WS2812b "protocol". With the old firmware, I could control 2 voltage controlled RGB LED/Led Bars,
with this new firmware, I can control up to two lines of WS2812b .. and a combination of both,
controlling voltage-controlled RGB LEDs (like those high power 3W or 10W) and two lines of WS2812b,
would be possible too.. I just don't have some RGB leds here right now [wink]

test_2_640.png 

So I connected the FTDI to the Intel NUC of one of my Artemis consoles, this time used as a server, just for
the quick test. Everything worked. Not quite out of the box, I had some problems while writing the firmware,
in fact it was a broken SN75176 transceiver.. I wondered why the DMX board did not receive any serial/dmx
data, searched for software or pebkac reasons and the last thing was to change the dmx transceiver chip,
which solved the problem. Lesson learned: If dealing with rs485, always have spare transceivers ready [wink]
(okok, it was the first broken transceiver chip in 10 years or so..)

test_3_640.png 

These WS2812b stripes are quite bright. Each LED chip consumes about 70mA if fully powered up, so this
stripe of 30 LEDs would consume 2.1A .. the onboard regulator provides about 1A .. so I think if I would
provide more power, the LEDs would be much brighter.

The first picture with the white LEDs is value=5 in dmxcommands.xml, the second picture with blue
light is original (I think value=200?) dmxcommands.xml ..

test_4_640.png 

As a last "test" I taped the LED stripe to the console monitor (DELL E2014T with touchscreen).


It is not the first time I used this setup. This time (because of some .. erm.. backup issue..) I
had to rewrite the dmx-pcb firmware from scratch (okok, the dmx receiving codes where kept),
but my bridge components where used 3 times at a local event - http://www.npl.ch . The site
is german only, but I think you'll figure out your way to the picture gallery.

npl 39.1 - first time I've ever seen Artemis SBS. npl staff had a two bridge setup, we had a lot
of fun.

npl 43.2 - second time I brought my stuff.. I asked for a joystick for helm, they put one up. Btw,
I am the guy on picture 9 with the "s+" and the tablet ..

npl 47.1 - only few images, this was the event with LED stripes .. At the beginning, they said "It's
to bright, less brightness to the LEDs, please" .. instead of altering the dmxcommands.xml, I just
put in a factor in the firmware to adjust the brightness [wink]

The pictures on npl.ch are not really Artemis-specific, there are only few pictures, but you can
imagine how well the reception is. I was not there the last two events, and I am not the person
who brings the "normal" setup. I just added some stuff on 43.2 and 47.1 - and will perhaps on
the next event in 2016 ..

---

I think I will take the time to design a single PCB with FTDI for DMX input from Artemis or similar
software, a DMX output, some WS2812b control lines.. to reduce this 3 pcb monster to one single
PCB..

I once experimented with the Artemis Network Protocol and a microcontroller with ethernet port ..
That was before "Data console" - Perhaps I can revive these experiments. Something involving
a small LiPo, WLAN, MCU and LEDs, powered by the LAN protocol, not DMX .. or even both? Well,
many possibilities..


Greetings from Switzerland,
Tim

Previous Topic | Next Topic
Print
Reply

Quick Navigation:

Easily create a Forum Website with Website Toolbox.