Addressable Servo

Hi,

I'm working on a project to put automated blast gates in my workshop, I've seen a couple of videos online which gave me the idea.

I've designed and 3D printed a blast gate which uses a 270° servo to open and close, and have got this working on an UNO.

My plan so far is to have a custom PCB on each blast gate supplying the regulated 6V, PWM signal and I2C buffer, with the data being sent along an I2C bus. These will then be daisy chained (probably using RJ45 cables). I'll power the PCB from a 12V supply as this will be fed from a larger PSU at the start of the chain. The controller will be located in the centre of the space and have buttons for each machine. I'll need to open and close certain combinations hence the central controller as opposed to machine activated.

I've seen the PCA9685 which looks as though it'll work, although 16 channels is a tad overkill, but at £1 each for the IC they are not too expensive.

Firstly does this all sound viable, or would anyone have a more elegant solution. Ideally I want to avoid lots of cables running around my workshop, I often move a piece of equipment and changing lots of wiring will be a nuisance.

James

What's a blast gate?

with the data being sent along an I2C bus.

How long are the wires for the I2C bus. I2C is not meant to send signals very far. Usually between parts on the same PC board or very close. If the distance is more than around 1/2 meter you may need to take special precautions. If the distance is very far, RS485 may be better for your addressable nodes.

Blast Gate is for controlling extraction for power tools, not sure why it's called that to be honest, their basically sliding gates that shut off vacuum to one tool and it can be opened on another.

groundFungus:
How long are the wires for the I2C bus. I2C is not meant to send signals very far. Usually between parts on the same PC board or very close. If the distance is more than around 1/2 meter you may need to take special precautions. If the distance is very far, RS485 may be better for your addressable nodes.

This was a concern, it will likely be around 2m between tools, I did read something that suggested with screened cables and buffers it "may be ok". I'd prefer a more robust solution if possible.

I'm assuming with RS485 I could in theory communicate between multiple "arduino's" albeit striped down and laid out on a custom PCB as there isn't really room for anything else.