HI. Is there any way to add a generic button that controls many gpio states. basically if i press the button it should turn relay 1 on then relay 2 then relay 3 and should i press the button again it must turn off relay 3 then 2 then 1. i do not want to use if and then as this will cause a short circut in my wiring.
If you are on an Arduino, you can use the virtual buttons and handle your logic there.
A silly circuit I made to share 1 receptacle with up to 4 freezers. The cycle time, in normal use, would be about 20 minutes per each relay cycle. This allows me to plug in 4 freezers into (1) 20Amp outlet, (assuming a 25% duty cycle on each freezer) without blowing a fuse. This was made for an ice cream vendor, using a small portable generator at festival events. It was successfully used with THREE freezers- and is still being used today!