Pages: [1]   Go Down
Author Topic: cue light system, half duple serial over long distance and power over the wire  (Read 962 times)
0 Members and 1 Guest are viewing this topic.
0
Offline Offline
Jr. Member
**
Karma: 0
Posts: 50
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

im having an idea of a cue light system for theater use. a cue light system is a system to let actors or the crew behind the stage to know when to enter the stage or pull a rope.

system idea
One master control panel with leds and buttons for every cue light. sevral cue lights with 2 color led and a button.
the scenario is when the stagemanager want to cue some one. the stage manager is pressing a standby button for the chosen cue light. the cue light lights upp with red wich means standby. the actor presses the button and the cue-light changes to green to indicate that the standby button is pressed. and a led changes at the master controller. when the stage manager want the actor to enter the stage he presses another button and the cue light led goes dark.

im thinking of using arduinos or attinys for this system and it involves duplex or at least half duplex serial communication.
a error checking system.
i also want it to be abel to use 3 wire microphone cable. the same for both data and power.
i also want it to be able to be use both as as star network or dasiy chained.


What i need help with from the community is what protocoll to choose and what hardware is the best to use.

i guess i might be needing something like rs485 or can bus.

rs485 pros
very good for use over long cable length
several nodes on one line without the need to boosting the signal
possible to make both star like networks and daisy chain networks.
reminds of dmx512 wich is something i feel safe with.

rs485 cons
needs at least cables with 6 lines for ful duplex and power

CAN bus pros
very good over long cables
several nodes in one serial line without booster
priority on trafic.
same line for both rx and tx.

CAN bus cons
needs for 4 lines for power and data.

i belive it would be possible to use a single wire for duplex data and/or it possible to somehow modulate the data to the power lines.

i have now idea what hardware or protocoll to use only that it should be possible.


Logged

UK
Offline Offline
Shannon Member
****
Karma: 184
Posts: 11197
-
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

This sounds like a one-way communication system so you wouldn't need the full set of lines for duplex communication.

I imagine that you'd program the sequence of cues in advance so that the stage manager just has to control the timing rather than remember each one. In that case, providing an easy way to configure, view and control the cues might be an important requirement. One way to achieve that would be to put the user interface on a laptop, and just use the Arduino to turn the LEDs on and off on demand using your distributed nodes and serial links. Do you think radio communication would be viable in that environment?
Logged

I only provide help via the forum - please do not contact me for private consultancy.

Global Moderator
Offline Offline
Brattain Member
*****
Karma: 452
Posts: 18694
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

rs485 cons
needs at least cables with 6 lines for ful duplex and power

Won't you have a power point at each end nearby? So you don't really need to send power.

You could do half-duplex, I have an example here:

http://www.gammon.com.au/forum/?id=11428

You send a query, switch back to listen for a result. This could be done multiple times a second (eg. "turn LED 4 on, are any buttons pressed?").

Logged

Offline Offline
Full Member
***
Karma: 1
Posts: 135
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Sometimes, it is not number of wires that matter, it is how good the cable is and how easy to get decent cable that can endure wear and tear in real life environment. I would suggest using cat6 ethernet cable that can be easily purchased with high quality and enough length, easy plug-and-play connection.

As transmitting power over the wires, 24V over the cat6 cable should not be a problem if not over too long distance. I have seen (and have worked on) an industrial strength lighting system using this kind of setup.

Disclaimer: I am suggesting this because I do have a RS485 shield that is exactly what I described, with thermal fuse to protect accidental shorts when powered over the cable. So please take my suggestion as biased.
Logged

Search for "mjkzz" on eBay :-)

Earth
Offline Offline
Edison Member
*
Karma: 41
Posts: 1388
My browser no longer is binding static IP, Floating is the way to go.
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

few plans;-


Plan A.
Wired
wire Cat5/Cat6 cable to each location
each node= Arduino+ POE Ehternet shield
Power over Ethernet is injected onto the cable at a
voltage between 44 and 57 volts DC, 48 Volts.

PoE Power Class      1   2   3
PSE Power available   4.0W   7.0W   15.4W
Max device power   3.84W   6.49W   12.95W
select Class base how many juice you need.

Plan B.
No Wire
Powerline Ethernet Adapter, if each location has AC.
each node= Arduino+  Ehternet shield
one more ac Adapter for Arduino power.

Plan  C.
Wireless.
each node= Arduino+ WiFi shield

Plan D.
Wire RS485
wire Cat5/Cat6 cable to each location
Power Over Ethernet Injectors/Power Over Ethernet Splitter 5v
to send power over. ( confirm with POE pinouts only wire DC+ DC-)
I am sure some one here may come out better plan, at least you need one start.
















« Last Edit: February 16, 2013, 12:27:55 am by sonnyyu » Logged

UK
Offline Offline
Shannon Member
****
Karma: 184
Posts: 11197
-
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Given that each remote just consists of a bicolour lamp and a button, you could just hard wire them all back to the central controller (e.g. using one CAT5 per remote) and not actually have any electronics or power at all at the remotes.
Logged

I only provide help via the forum - please do not contact me for private consultancy.

0
Offline Offline
Jr. Member
**
Karma: 0
Posts: 50
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Thanks for the ideas and the input on using ethernet cable and going wireless

But i want to use 3 wire (microphone cable) because it´s durable and the xlr connector i rugged. microphone cable i also very easy and cheap to get.Your are right that its not the wires that is important but in this case it is. the wireless idea will not because the 2.4 Ghz is very crowded already. it also would be needing batteries and some one to turn it on and off and thats is a problem because it is adding error sources.thats why ac on the que light spot is also not an option. all the systems i have seen so far doesn't use a smart micro-controller quelight with the possibility send feedback to the master controller and that works over standard microphone cable.

the quelights needs to be able to connect in a series and in a star network because cables are expensive and running them is time consuming, using one line minimize that. in some situations it is easier to use parts of the network as a star network around a splitter or switch.

I got the idea with the microphone cable from wired intercoms like clearcom or telex. They have duplex audio communication and power on 3 pin microphone cable. in the intercom example one wire has ground, one wire has power and one is for audio. thats why i though that it is  possible to have rx and tx on a single cable. I know audio and data is not the same thing but audio cloud be a very slow data rate.

POE mode A is an interesting way to approach this also some kind of phantom power circuit.

more ideas are welcome
Logged

0
Offline Offline
Jr. Member
**
Karma: 0
Posts: 50
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
You could do half-duplex, I have an example here:

http://www.gammon.com.au/forum/?id=11428

You send a query, switch back to listen for a result. This could be done multiple times a second (eg. "turn LED 4 on, are any buttons pressed?").

thanks this together with some phantom power circuit or POE could do the trick.

any ideas?
Logged

Earth
Offline Offline
Edison Member
*
Karma: 41
Posts: 1388
My browser no longer is binding static IP, Floating is the way to go.
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
Quote
You could do half-duplex, I have an example here:

http://www.gammon.com.au/forum/?id=11428

You send a query, switch back to listen for a result. This could be done multiple times a second (eg. "turn LED 4 on, are any buttons pressed?").

thanks this together with some phantom power circuit or POE could do the trick.

any ideas?

If you go this route, you might need over voltage protection. since LTC1480 might be uncomfortable with short to  44 and 57 volts DC. Here is the plans;-

Plan A.
Dia Surge Suppressor Discharge Gas Tube

Plan B.
Clamping diode

Plan C.
Catcher diode

Plan D.
Zener diode

Plan E.
Metal Oxide Varistor

Plan F.
Multi-layer varistor

Plan G.
TVS diode

Plan H.
TVS IC



 I am sure this list could be very long.  I just started.


« Last Edit: February 17, 2013, 08:45:52 pm by sonnyyu » Logged

Pages: [1]   Go Up
Jump to: