Addressable relays for light installation

Thread Starter

Mark de Reijer

Joined May 14, 2019
4
Hello guys,

For a volunteer artwork project, I want to switch 30 230v light bulb - stretched over 35 meters.

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 - addressable relays just like those ws2812 LEDs or DMX. Significant less cable is needed this way and I can connect them any way I want.

Preferably they have their own address so I can send a command like '14 1' which turns on the 15th relay.

Needless to say it needs to be relatively cheap. So giving each relay an Arduino with dmx shield would be a bit too 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 tho)

Thank in advance for your advice,
Mark
 

Thread Starter

Mark de Reijer

Joined May 14, 2019
4
To clarify:
  • I would like to use 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 from the speed and lifespan limitations of mechanical relays (vs solid state).
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
.
 

djsfantasi

Joined Apr 11, 2010
9,156
If you’re not afraid to roll your own, you could design a board with a serial input into a shift register. Reserve a bits for the address and c bits for the action.

In your case, you’d need 5 bits to address 32 devices. If all your looking for is on/off control, you’d need 1 bit for the action. 6 bits total. You could use two bits for error detection. Everything would fit into a byte.

An ATTiny46 could process the bit stream on the bus and shift out the data to an 8 bit serial-in/parallel-out shift register (74164?).

From there, add a DIP switch to select the address for each board, a few AND gates to decide the address and a MOSFET to drive a relay. A few miscellaneous resistors and you’ve made your own addressable relay.

I mention this as an alternative. However, your cost will approach the $12 SparkFun solution, which will give you much less anguish. So after a rough design and cost estimate, @marcf has the best solution so far.
 
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