3 serial ports with only 1 pic

[Algerian]

Hello, I want to ask help
Does anybody know how to do to use 3 serial ports with only 1 pic16f877,
I want to use 1 serial port rs232 to communicat with PC and 2 others to communicat with Barometer, and Thermometer.
Thanks in advance for any help or advice you might provid.

 

[Nigel Goodwin]

Simply use two software UART's, and one hardware one.

 

[Algerian]

Thanks for reply, but could you give me more explication please.
I can't enter the site you gave me.

 

[Nigel Goodwin]

Thanks for reply, but could you give me more explication please.
I can't enter the site you gave me.

I would use software UARTS for receiving the data, and the hardware UART for sending it to the PC - both are covered in my tutorials - just checked it, the site is working fine.

 

[Pommie]

The only problem with the serial routines on Nigel's page is that they can't send and receive at the same time.

In this thread I posted code that allows 8 channel RS232 to run simultaneously.

Mike.

 

[Papabravo]

If your PIC has an SPI peripheral you could use a pair of MAX-3100 UARTS. It is a very capable chip, with an excellent datasheet. One nice feature is that they have receive FIFOs which are 8 bytes deep so you don't have to service them each time a character comes in but can do it in bursts.