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chrispol
- 12th January 2005, 17:32
Right now i'm running a max 232 for communications to a pc, i will need to communicate to another pic but am out of ports on a 18f458 <g>, can i splice the other pics onto the tx/rx lines after the max 232? i assume anything brodcasted would hit the pc serial port and vice versa but thats not a big deal, whats the max length of line fom pic to pic?

Or another way would be to add rs485, but being out of pins it would be a bit tough....

any suggestions?


Thanks

mister_e
- 12th January 2005, 17:57
can i splice the other pics onto the tx/rx lines after the max 232?

no max 232 will not support multipoint *kinda network* IMO. if you want to do something like that you will need to use RS485/RS422 drivers like MAX485 or else who support multipoint. OR add another Max232 on the same PIC tx/rx pin. For the RX you'll need diode mixer or something like that to avoid short between signals.

But you can test with MAX232. TX could be tie together, RX... diode mixer with pull down. Could work on some case!!