Registered: 1446907247 Posts: 11
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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 And I had a couple of these laying around: 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: 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 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 (okok, it was the first broken transceiver chip in 10 years or so..) 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 .. 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 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