I've got the following - kind of conceptual - problem. Brief overview: I need to attach some smart sensor (like an IR beam break) to several boxes with open front. The purpose is to receive an information about which box the operator pulls out the thing from. Each of those boxes also needs to have two LEDs. The idea is to connect all of the sensors using some bus as I2C, 1-wire etc, to reduce the number of required wires and Arduino input pins. Do you guys see any potential solution that might meet those requirements? What additional hardware would be required. Have you ever seen or used the beam break sensor that use some communication bus?
What is the distance between the boxes?
How much money are you prepared to spend per box?
If this is for a manufacturing environment I would use one Arduino clone per box with a Modbus or CAN bus interface linking them together. Cost wise ~$7 per box is achievable.
The intention is to have about 40 boxes matrix - let's assume 8 stacks each one containing 5 boxes (please find attached image). So the distance between them varies from couple centimeters to even couple meters. Another requirement is the mobility, the boxes will be moved around couple times during a month. So the best solution would be to use some contact connectors. However your hint provoked some further thoughts in my mind. Maybe it would be enough to use 1 arduino board per stack, so that each single unit would serve 5 boxes. And as you suggested the boards would be then communicating via bus...
In terms of costs, the cheaper the better However reducing the costs under $200 would be appreciated.
However reducing the costs under $200 would be appreciated.