Hi!

I want to build a device with 89c51 and communication bus. It must be opto-isolated, every device with its own address, and capable of connecting 50-100 devices in a bus. I was thinking of I2C, software implemented in 89c51 and two opto isolators. Devices will be app 10m apart (fan coil controllers). Speed is no limit, it can be slow. Project is low budget, so it must be cheap.

Does any of you have some experience about this kind of bus?

Replies welcome!

Regards, Damjan