Updating / Replacing a 1970's Home Automation System

Well that is a mighty impressive piece of electrical engineering!

Have you considered replacing the guts of the panel with an Arduino MEGA which has lots of digital inputs and outputs on it that would allow you to keep all of your low-voltage wall switches, although the 28VDC would need to be stepped down to 5VDC. You could get some 8-way or 16-way relay panels very inexpensively to replace the old relays assuming dimming is not required.

Arduino MEGA 2560 - http://amzn.com/B006H0DWZW - $~35
Arduino SmartThings ThingShield - ~$35 (for integration into SmartThings)
SainSmart 16-Channel Relay Module http://amzn.com/B0057OC66U - ~$25

So that is about $100 worth of parts to get 16 relays and preserve the low-voltage switches. Much less expensive than about $675 for 15 Aeon labs micro smart switches.

Plus, the best part is you get to write a bunch of code! That’s the real fun! I have created a re-usable library for the ST Community that actually helps to make this process much simpler.

Check it out at