Film-Tech Forum ARCHIVE: DoReMi Serial and Arduino

This is topic DoReMi Serial and Arduino in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Max M. Fuhlendorf (Member # 6342) on 08-15-2018, 09:01 PM:

Hello.

I work in a theatre with manual light switches, and want to automate them. There is no budget for professional equipment, so I thought I could try my hand using automation cues from the server (an old Doremi DCP-2k4) and an arduino with dimmers/relays to control the lights.

I was thinking of using the GPO lines to control the arduino board, but the manual says it requires a Dolphin card, which is not installed. The manual says nothing of the motherboard serial RS232 port, does it work?

I'd love to hear your opinions.

Posted by Marcel Birgelen (Member # 6801) on 08-15-2018, 11:45 PM:

If there's no Dolphin board installed, how exactly do you connect the projector to the DCP-2K4?

The Serial implementation is extremely straight forward and it's only one-way communication.

First you add a new serial device in the CineLister software, where you specify the serial port (usually just one, unless you connect USB to Serial devices), speed, data bits, stop bits, parity, etc.

You also specify the Message Type, which can be either a fixed length or one with an end-of-message delimeter like the end-of-line character.

Once you've configured the device, you can send simple, ASCII encoded messages over serial to it in any automation cue.

So, if you connect an Arduino to it, you simply open the port at the correct settings with the correct speed and you can implement a simple Serial.read() loop to fetch the input and parse commands you defined yourself.

Posted by Carsten Kurz (Member # 5396) on 08-16-2018, 05:05 AM:

There are many Ethernet-Relay boards available on the D.I.Y. market.
Of course, RS232 with an Arduino is possible as well.

However, all Classic DCP2000/2K4 servers with Built-In MediaBlocks and and thus Dolphin 1.0/1.2 do have their own GPIOs on a DVI-connector. It's very easy to attach relays and switches to it. It may be, though, that your Doremi has been converted to a ShowVault with an IMB in the projector - then the Dolphin card is gone, and you may use the GPIOs on the IMB (dual RJ45 connectors). The use of both is well documented in the Doremi field installer manuals.

Maybe you can show us a picture of the rear end of your Doremi. The DVI/GPIO connector is located above the dual HD-SDI connectors. It looks like a DVI port, but it's just the connector, the pinout is completely different from DVI.

- Carsten

Posted by Dennis Benjamin (Member # 1137) on 08-16-2018, 05:44 AM:

quote: Carsten Kurz
Maybe you can show us a picture of the rear end of your Doremi.

My teenage self just wants to laugh at this. [Wink]

Posted by Dave Macaulay (Member # 813) on 08-16-2018, 06:02 AM:

Yes, serial works. You create a serial device in device manager, the port settings are there. Then you create macros that send text to the device.
I assume you have a server that the media block has been removed from? They should either have the Dolphin card - with GPIO connector - or a PCIe connector for an IMB in a projector. You do need one or the other of these media block options to get video on screen.
I have avoided using GPIO because a Jnior is easier in most applications. Serial is useful for the occasional thing that wants it.

Posted by Max M. Fuhlendorf (Member # 6342) on 08-18-2018, 05:36 PM:

Yes! You were all right [Big Grin]

, the IMB is installed in the Barco with a PCIe connector to it. I didn't recognize the connector at first:

And what you guys said about the serial comms is just what I wanted to know, that you can send serial commands via the RS232 port. It is not well documented in tha paper manual I have here, I just downloaded a PDF copy. I will tinker with this and if/when I get around to actually building it, I will post some pictures here.

Thanks guys for all the help <3

Posted by Stephan Shelley (Member # 8587) on 08-18-2018, 06:09 PM:

You can also use the GPO on the IMB to do it like you originally planed.

Posted by Carsten Kurz (Member # 5396) on 08-18-2018, 08:32 PM:

There are 4 inputs and 4 outputs on the IMB, each on an RJ45 socket (GPI/GPO). They are optoisolated, so you don't risc much on the precious IMB. The ShowVault field installer manual has circuit diagrams and basic schematics on how to use them. You can also buy cheap relay boards from ebay (those dedicated to Arduino or Raspberry PI projects), so you can get started for just a few bucks with some dumb on/off relays.

- Carsten

Posted by Marcel Birgelen (Member # 6801) on 08-19-2018, 03:28 AM:

You should also refer to the manual of the Doremi ShowVault and not the DCP-2K4.

This machine might have started as a DCP-2K4, but it's technically now a ShowVault.

In there, you'll also find the pinout of the GPIO ports in the manual of the IMB.

Posted by Pete Naples (Member # 761) on 08-19-2018, 10:42 AM:

If you do use the GPIO on the IMB, and it doesn't work. Don't necessarily blame yourself.

There are some out there with components missing which prevent the ports working. A colleague found this out after scratching his head for a long time on one job.
Presumably so few people use GPIO form the IMB nowadays that Dolby have never bothered with a Field Bulletin or recall.

Posted by Gordon McLeod (Member # 33) on 08-19-2018, 12:48 PM:

If entering serial commands do it in hex not asci as the carriage return that they have doesnt always work

Posted by Marcel Birgelen (Member # 6801) on 08-19-2018, 04:26 PM:

I usually put the carriage return in the message format. That usually works, even with ASCII messages.

Posted by Carsten Kurz (Member # 5396) on 08-19-2018, 07:38 PM:

It's very easy to test the ports for function with an Ethernet cable cut into two halves, and a basic multimeter. The built-in GPOs can very easily be addressed using the macro editor. If, for some reason, they shouldn't work, serial is your next step.

- Carsten

Posted by Max M. Fuhlendorf (Member # 6342) on 01-29-2019, 08:44 AM:

quote: Carsten Kurz
It's very easy to test the ports for function with an Ethernet cable cut into two halves, and a basic multimeter. The built-in GPOs can very easily be addressed using the macro editor. If, for some reason, they shouldn't work, serial is your next step.

- Carsten

Thanks, I already did that, and I have all the components I'll need: the IMB board is working perfectly. One question: if I use the GPO outputs to drive a common 5V relay directly, can I just connect it or do I need to add some resistors in series?

Posted by Carsten Kurz (Member # 5396) on 01-29-2019, 09:13 AM:

You should probably not drive a 'simple' relay directly. Even if the IMB itself is protected through the optocoupler, it may blow the secondary component of it, and the GPO may become disfunctional. Use at least a flyback diode.
There are many cheap relay boards available on ebay and amazon for Arduinos, Raspberry PI, etc,, and most of them offer optocoupler or at least transistor input stages. Use one of these. Very often, they can be bought for less than a single basic relay costs locally.

https://www.ebay.com/itm/5V-1-2-4-6-8-Channel-Relay-Board-Module-Optoco upler-LED-for-Arduino-PiC-ARM-AVR/401237960337?hash=item5d6ba56691:m:mzkfWblEtqpHZfTceI9Bh9A:rk:1:pf:0

The IMS1000 manual has GPIO circuits that will help you (from page 290):

https://www.mteworld.com/content/IMS1000_User_Manual_002949_v1_4.pdf

It shows direct connection of a basic relay coil as a GPO example and gives tech specs, but I would still avoid to do it that way. The circuit diagram also shows self-resetting fuses for every GPO, but, still...
Just buy one of those boards and play safe.

Many Maker shops will sell these boards in your country as well, I guess, at slightly higher price, but then, shipping is usually faster than from China.

You can continue to use these boards even if at some time you may choose to switch from direct GPO to e.g. serial with an ARDUINO inbetween.

- Carsten

Posted by Max M. Fuhlendorf (Member # 6342) on 01-29-2019, 10:52 AM:

quote: Carsten Kurz
Use one of these. Very often, they can be bought for less than a single basic relay costs locally.

Oh, yes, I bough a relay board with optocouplers (just like the ones in the link you sent, thanks!) for extra safety. This is what I'm going to use, actually. I was just wondering if these optocoupled relay boards might draw too much current from the GPOs (they draw about 100ma to operate the coils, I read)...

Thanks for the assistance, I'm somewhat of a noob with this.

Posted by Tony Bandiera Jr (Member # 2365) on 01-29-2019, 11:05 AM:

quote: Max M. Fuhlendorf
Oh, yes, I bough a relay board with optocouplers (just like the ones in the link you sent, thanks!) for extra safety. This is what I'm going to use, actually. I was just wondering if these optocoupled relay boards might draw too much current from the GPOs (they draw about 100ma to operate the coils, I read)...

Thanks for the assistance, I'm somewhat of a noob with this.

I'm willing to bet that the boards have a separate input pin for "power" and "ground" to drive the relay coils. You will need to provide that input voltage with a small power supply.

Usually, one of the points in using an optoisolated or transistor driver boards is to avoid having the host device seeing the burden of the relay current (and the spikes caused by the coils.)

Posted by Max M. Fuhlendorf (Member # 6342) on 01-29-2019, 11:08 AM:

quote: Tony Bandiera Jr
I'm willing to bet that the boards have a separate input pin for "power" and "ground" to drive the relay coils. You will need to provide that input voltage with a small power supply.

Usually, one of the points in using an optoisolated or transistor driver boards is to avoid having the host device seeing the burden of the relay current (and the spikes caused by the coils.)

It does

I was just reading about it now. Feeling a little silly having come here to ask these questions before reading about the optoisolated relay modules a little more.

Thanks!

Posted by Carsten Kurz (Member # 5396) on 01-29-2019, 11:14 AM:

Yup. The relay boards I linked to above offer supplies for input and coil switching circuit, and a jumper to split them if necessary. Typically, the easiest way to do is to use a simple USB wall charger. Some of the larger boards may need 12V instead of 5V.

- Carsten

Posted by Marin Zorica (Member # 1716) on 01-29-2019, 05:29 PM:

If using arduino, get some more programming and use it with ethernet shield, so you can hook up to ethernet of server-projector network which has some adventages like:

-you can have long cable (ethernet)
-more isolated from server
-more than one device can be hook up with different IP

I did it many times for using with any kind of automation and works perfect........

Posted by Max M. Fuhlendorf (Member # 6342) on 01-30-2019, 08:13 PM:

quote: Carsten Kurz
Yup. The relay boards I linked to above offer supplies for input and coil switching circuit, and a jumper to split them if necessary. Typically, the easiest way to do is to use a simple USB wall charger. Some of the larger boards may need 12V instead of 5V.

Perfect! I used an old router 5V power supply, and tested it today, the relays worked perfectly. The only thing remaining to do now is install it next week. Thanks for all the help! [Smile]