Fitting a serial converter and lead insider the I/O Bus box gives us back a socket for other projects and gets the serial converter out of harms way. Cutting a couple of I/O Bus tracks opens up even more options.
I have been using the 5 port ‘scart socket’ I/O Bus simply as a passive backplane. All of the lines are bussed together and using it simply involves hooking up the correct pins of a scart type plug to the corresponding pins on a circuit.
The I/O bus started life as a cheap breakout box for the Sweex/Edimax Router so that I could hook up different circuits to it without risking physical damage to the router itself – at least I won’t be able to break off a component whilst connecting a new circuit.
The Bus simply carries the router led, power (3v and 5v) and serial lines. I have been using a transistor based level converter to connect the router to a PC for uploading new ROM images.
Now that I’m going to add a PIC Processor and try a bit of communication between the PIC and the Router, it occured to me that it would be useful if I cut the serial lines somewhere on the bus so that I could hook up more than one serial device & converter.
However, there is just room for my level converter or one based on a MAX232 IC (a better idea if you have one handy) where the original scart lead exited the case.
I added the circuit, connecting it to the nearest socket and cut the traces between the serial pins and the rest of the I/O Bus.
Now, if I need to boot the router and upload a new ROM Image or work with the serial port, I plug the router into the first socket. If I move the router to another socket, I can plug a PIC or whatever into the first socket and upload software to that.