RS 485 PIC to PIC

[kazimor]

Hello, i need some help for a pic to pic master/slave connection with RS 485,
i know using RS 232 is much better but for my project i need the RS485
i'm using ISIS for simulation,
PROTON IDE and CCS C for programming
if anyone have a simulair project that works, pls help me out,
thank you

 

[andre_luis]

The RS-485 stands for the electrical specification, as well as the RS-232, so from the programming perspective, you just deal with the UART.

 

[FvM]

so from the programming perspective, you just deal with the UART

Mostly. RS-485 needs additional transmission enable signal. Depending on the used processor, it can be generated in hardware by the UART or has to be software generated software. CCS C example ex_modbus.c demonstrates handling of TX-Enable in software.

 

[kazimor]

Mostly. RS-485 needs additional transmission enable signal. Depending on the used processor, it can be generated in hardware by the UART or has to be software generated software. CCS C example ex_modbus.c demonstrates handling of TX-Enable in software.

do you have any examples please when it comes to soft ?
thank you

 

[dick_freebird]

RS-422 and RD-485 are both pretty low BW and the piece parts for RX, TX
and bidirectional are all going to be in 5V technology.

What about LVDS (90LV31, 90LV32 or similar) if you're short-haul and have
a decent ground integrity between the two ends (common mode of ~ 1V
rather than 7V)?

RS-422, RS-485, TIA644 are all just physical layer, bang-bang specs (w/
some stuff about data rate vs line length).

 

[Aussie Susan]

Read up on exactly what RS-232 and RS-432 are (@andre has already given you a big hint).
Then you will realise that they are HARDWARE protocols and nothing to do with the software.
There are MANY examples of how to use a UART both in these forums and on the Internet.
Susan