For a volunteer art work project I want to switch 30 230v light bulb - stretched over 35 meter.
Hardwired would be the best way to go ( no unstable wireless) because it needs to be robust and they will be switched on/off fast (the delay has to be minimal).
Therefore I would like to daisy chain the relays - adresable relays just like those ws2812 Leds or DMX. Significant less cable is needed this way and I can connect them anyway I want.
Preferably they have their own adress, so I can send a command like '14 1' which turns on the 15th relay.
Needles to say it needs to be relatively cheap. So giving each relay an arduino with dmx shield would be a bit to much.
I envision this to be controlled by one arduino (with a dmx shield if possible).
I've searched the internet for inspiration and similar projects but couldn't find one.
Could you tell me how you would have done something like this? Or maybe there is a better way than mine? Or is led the way to go (cost vs aesthetics, bulbs are way more beautiful)?
You didn't mention what kind of lights or what the purpose is. You wanted speed so I wondered if you need to turn them on or off often. So you might want to use solid state relays and not mechanical ones.
While mechanical relays can operate very many times they will degrade with increased operations. And mechanical relays consume more power in the coil circuit so you need a dc power supply that can meet the power your relays would need.
Solid state relays need very little power to switch them on. No more than what it takes to light an led. But there is some loss at the high voltage part. They will drop about 1 volt so the power dissipation would be 1 Watt for every amp the lamps take.
Look at X10 powerline communication. The relay modules are relatively cheap and you only need to buy one gateway for your Arduino or PC to control them.
The safety benefits of not running low voltage wires alongside your mains power wires are huge.
spycatcher2k:
Just use a mega2560, plenty of output pins, use transistors to activate the relays. I would run cables to the arduino's location, rather than have control lines fanning out.
This would mean I need an awful lot of cable. I need to switch 30 bulbs, ever meter. So this means 2x1 meter + 2x2meter + 2x15 meters would add up to 242meters(!) of cable. You get the point Just one data cable would be way more ease. And it should be possible since ws2912 leds or DMX systems work with the same principle.
Rudy216:
You didn't mention what kind of lights or what the purpose is. You wanted speed so I wondered if you need to turn them on or off often. So you might want to use solid state relays and not mechanical ones.
Just normal 230v ~25w household lightbulb, the purpose is a 'light' show among a path of 35 meters. Each bulb is placed roughly every meter. I am away of the speed and lifespan limitations of relays.
Rudy216:
While mechanical relays can operate very many times they will degrade with increased operations. And mechanical relays consume more power in the coil circuit so you need a dc power supply that can meet the power your relays would need.
Yes, i am aware. I would use a small transformer to get 5v/12v dc for each relay unit.
MorganS:
Look at X10 powerline communication. The relay modules are relatively cheap and you only need to buy one gateway for your Arduino or PC to control them.
The safety benefits of not running low voltage wires alongside your mains power wires are huge.
Thanks, I will look into it!
In addition; the kind of bulbs and switching times are subordinate. Most important is to daisy chain them (like ws2811 leds). If switching times and or watts are limited - I will be able to live with that :).
Just one data cable would be way more ease. And it should be possible since ws2912 leds or DMX systems work with the same principle.