Hello there. I have had a sort of pet project buzzing around the cobwebs of my skull for some time, that the appearing of the Raspberry Pi may make a bit more probable. This project would work with a grid, say, of 5X5 units, each communicating to the N, E, S and W neighbour.
In the happy past I used serial ports, and I would happily go on with my planning if the R-Pi had, within its already impressive specs, not one but 4 UARTs.
Do you hardware tinkerers have an idea on whether it will be an easy task to equip the board with three more UARTs? Or, since I know both I2C and SPI are serial buses, would it be possible to connect, say, the rows via I2C and the columns via SPI? Can such buses work on distances of, say, a couple of meters of cable? And can data travel bi-directionally on these busses?
Thanks in advance