re multiple inputs for pc in article u uicvm uic edu u uicvm uic edu writes can anyone offer a suggestion on a problem i am having i have several boards whose sole purpose is to decode dtmf tones and send the resultant in ascii to a pc these boards run on the serial interface i need to run of the boards somwehat simultaneously i need to be able to ho ok them up to a pc the problem is how do i hook up serial devices to one pc inexpensivley so that all can send data simulataneously or close to it any help would be greatly appreciated are the boards at all intelligent i e run by microcontrollers the easiest thing would be to have another line that says that one of the boards is talking to the pc when this line was true the other boards could all hold off and not send their data this isn t a perfect solution though since you have to worry a little about making sure two boards don t decide to talk at the exact same time other than that i think you will need to hook up each board to something that speaks rs this actually isn t as hard or as expensive as it used to be though assuming the boards talk relatively slowly bps or slower the pics can coordinate things between themselves to multiplex the data this is really just forbicly adding the suggestion in the first paragraph to your system and it assumes that each board doesn t talk more than th of the time of for very long since a pic isn t going to be able to buffer more than maybe some bytes you might want to check into the prices of multi serial card for your pc though i recently bought a boca research x card parallel ports rs ports for a very reasonable joel kolstad
