Which relay to use?

[nicholseric]

Is anyone experimenting with the HAT based relays like this one? https://sequentmicrosystems.com/index.php?route=amp/product/product&product_id=50
If I have a light, pump and fan for each shelf on my grow rack, plus moisture and temp\humidity sensor, I quickly use up the available gpio's and can only serve up 5 shelf's per raspberry pi. One of these expandable HAT based relays could significantly scale this out but would require using different modules?

It seems like each crop should have its own lights, fans, pumps and sensors instead of a pi for each crop. I dont intend on having each shelf or each rack with a mono crop all on the same growing, lighting and watering schedule. Would that be too much of a re-architecture?

[nicholseric]

I decided on the non HAT for my prototype

[nicholseric]

Here it is all finished.