What could you possibly use 8 relays on a board for?

I’ll be honest, today is payday and, I’ve been thinking about improvements to existing projects, surf’n the web look’n to buy!  Then I thought of my binary christmas tree display.  I remember seeing an 8 relay board on the web a long time ago, and thinking what could I use THAT for?  I had to come up with an excuse to buy it of course.  I convinced myself I could build a holiday light display with a twist.  I decided I’d flash the lights in binary.  Check it out if you have not watched it yet.

Now that was a fun project.  How do I expand on that in the context of “the farm”.  There’s a solar array in the field  – ideas?

I can’t say I bought this one below – but they all look about the same.  When you are just having fun with an Arduino you can afford the 8 pins to drive these things.  I suspect some have a BCD to relay decoder chip built in.  That would reduce the number of pins you need to dedicate.  Or you can use a shift register (those are fun. Look em up if you have not considered them in your project yet).


5V Eight 8 Channel DC 5V Relay Switch Module for Arduino Raspberry Pi Arm AVR | eBay

So now you’ve got a project for yourself to figure out.  The code for an Arduino to do the above binary tree display was fairly simple.  You can get fancy if you want.  Where you’ll want to be careful is how you wire up the high voltage side of the system.  I took a lot of care modifying a power strip.  This had the advantage of 8 sockets ready to plug into.  Go for it – be safe.