How to communicate two devices with hardware USRT?

amit78 · Joined: 17 Jul 2009 Posts: 21 Location: Kolkata, India

Hi all

I am trying to develop a device (B) which will get some data by communicating with another device (A) with RS232 port. Now device B will process the data and then send it to PC in its COM port.

A<---------------->B<----------------->PC

My problem is I am using PIC18F452 and it has a single hardware USART (C6->Tx, C7->Rx). Using a MAX232 chip I can communicate it with PC. But now I need to communicate with device A also. How can It be possible to communicate with both the devices, because pin C6 and C7 is engaged now.

Thanks in Advance
Amit

andyfraser · Joined: 04 May 2004 Posts: 47 Location: UK

Hi,

Have a look at the MAX3100 SPI UART. It is very straightforward to interface to and will give you a second 'real' serial port.

Failing that you can look at the 'soft' UART provided by the compiler. You should search this forum for the limitations on using a software UART.

Andy
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