I am wondering if it is possible to make the RS2332 port a multi drop port by making the output Open Collector and providing a pull-up for communication rather that setting the port high internally. It would in my way of thinking allow several devices to share a set of pins which are scarce on an Uno. Spi and I2C are Ideally the ports but both will be busy in the design I have in mind where devices are broadcast to and the software in the 'receiver' reads the ID and then calls the appropriate function to deal with the communication. The same would work for 'Broadcast' communications to peripheral devices. I will have severaal devices that must communicate with the Master device, A scrolling display, X10 Communication from my 'console' and from remote devices, remote collection of termo and hygro information as well as local barometric data. I am using a GPS receiver for time data and because of the receiver limitations might have to be remoted to a better location. Ultimately this thing will also handle a radio and several gigabytes of MP3 files both from my bedside console and from at least one remote. So I have a need for one common radio/serial I/O port, just for communications. Perhaps the I2C would be best but the speed of communications comes close to the capacity of the Radios, whether I use a 4432 based 433MHz based comm link or I use the Nordic devices. I don't quite think those little 433 OOK devices are capable of the task as busy channel arbitration is a big issue to be handled in software... Any Idea's???
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