UART ttl level

Development Boards MicroMod
1

Hi all,

I am thinking to communicate AVR to other AVR via RXD TXD port without using the RS-232 level converter (such as MAX232). It means using the ttl level. My question is, what’s the maximum length of cable I can use for this kind of configuration ?

Thanks

Fayes

2

depends on cable, grounding, shielding, common power supply or not.

I’d recommend 12 inches to a max of 48 inches if things are ideal.

If you push the limits, then design and use an inter-AVR protcol that does error detection and retransmission.

3

If you want more length, why you don’t try the RS-422 or RS-485 instead RS-232??

4

Fleming:
If you want more length, why you don’t try the RS-422 or RS-485 instead RS-232??

First post says not using RS-232, wanting to use TTL levels direct from UART

I’m thinking a foot or two maybe?