Four RS232 ports on PIC

Started by Miem September 23, 2006
Hi,

I want to ask expert advise how can I create four RS232 interface on a
PIC microcontroller?

(I'm planning to use PIC18F6680)

Thanks,

Miem Chan
miemchan at gmail . com

Miem wrote:
> Hi, > > I want to ask expert advise how can I create four RS232 interface on a > PIC microcontroller? > > (I'm planning to use PIC18F6680)
First advice - write down the requirements and THEN choose a microcontroler having all the needed resources onboard. There are plenty of uCs with 4 or 5 UARTS, presumably not more expensive and faster than PIC (like Renesas H8 and M16C families). Why do you make things harder by sticking to the chip which is not suitable for your application? Having said that, you have at least 2 options if you decide to use that bad PIC ;): - implement a software UART using timer, interrupts and some fancy code, - buy an external UART chip with SPI interface (like Maxim MAX3100 if memory serves me right).
Miem wrote:
> Hi, > > I want to ask expert advise how can I create four RS232 interface on a > PIC microcontroller? > > (I'm planning to use PIC18F6680) > > Thanks, > > Miem Chan > miemchan at gmail . com
Whats possible depends on baudrates, traffic and what else you need to as well. You need to write a spec.
Miem wrote:
> Hi, > > I want to ask expert advise how can I create four RS232 interface on a > PIC microcontroller? > > (I'm planning to use PIC18F6680)
I designed a system like that where I worked some years ago for a comms hub, using four AT90S2313s (they have fast UARTs) connected to a PIC via SPI, using software SPI on the AVRs. The RAM on the AVRs was useful for buffering data. The system worked very well, I think it is still in production. Leon