Cable length to UART at 3V

Hello,

I'm developing a system with two PIC's that needs bi-directional communication.
They both work at 3V VCC, and I'll use UART at 9600bps.

I'll use 6 wire, crossed cable (3x2 pair) (like CAT5U ethenet cable), with 1xGND paired with 1xTX, 1xGND paired with 1xRX, and 2 other pair with VCC (3V). So the same cable will have regulated 3V/GND and TX/RX.

Is the best choice?
What is the maximum cable length that I should use?


Thanks for any tip,

JS

Not using line driver, just two PIC's...

I need it to be from 5 to 10mts...

What do you suggest?
MAX3232?

HI DarioG,

Do you think I can get 5-10mts without drivers?
Regarding the grounds what is your tips?

Regards,

JS

Since you are using a CAT5 cable, you might consider using an RS422 interface. Look at the MAX3080 and MAX3081 chips.

I think an rg58 cable would be better if you want to use one way in short distances (maybe 10 meters). But of course, you will need to use two power supplies.
RS232 is the most common, but RS485 will be better for longer distances since it is balanced.
Hope not to be too late.

cesardag
I think an rg58 cable would be better if you want to use one way in short distances (maybe 10 meters). But of course, you will need to use two power supplies.
RS232 is the most common, but RS485 will be better for longer distances since it is balanced.
Hope not to be too late.

Can either of those be made to stretch 8 years? I think you need a different physical interface and protocol for that.

I am facing the same issue when I connect micro-controllers it will loss data but the same code and circuit working with Modbus slave.
I am using dspic33 and UART1, For transmission I used interrupt.
 
clock
#define FP 60000000 /* FP = (FOSC/2) */
#define BAUDRATE 9600
#define BRGVAL 389
((FP/BAUDRATE)/16) - 1
 
U1MODEbits.STSEL = 0; // 1-Stop bit
U1MODEbits.PDSEL = 0; // No Parity, 8-Data bits
U1MODEbits.BRGH = 0; // Standard-Speed mode
U1MODEbits.ABAUD = 0; // Auto-Baud disabled
U1BRG = BRGVAL; // Baud Rate setting for 9600
U1STAbits.UTXISEL0 = 1; // Interrupt after one TX character is transmitted
U1STAbits.UTXISEL1 = 0;
U1STAbits.URXISEL0 = 0; // Interrupt after a character is received
U1STAbits.URXISEL1 = 0;
//
// _U1EIP =6;
// _U1RXIP = 5;
// _U1TXIP = 4;
//To enable UART reception using Interrupt
IEC0bits.U1RXIE = 1; // Enable UART RX interrupt
U1MODEbits.UARTEN = 1; // Enable UART