[Elecraft] Ethernet to serial adapters

[Augie Hansen]

Manuel Maseda wrote:
> ...
> Anyone have any experience with Ethernet to serial adapters?  Would it be
> possible to connect one to the K3 serial port?
>   

Lantronix and other manufacturers make some very nice Ethernet-to-serial 
modules. My experience developing firmware for a security system 
controller has shown that the XPort (wired) and WiPort (wireless) 
versions of the Lantronix modules are very reliable and easy to work 
with. They are designed to be soldered onto a circuit board, are RoHS 
compliant, and are available from Mouser. The XPort costs about $50-$60 
and the WiPort about twice that amount.

The K3 RS-232 port limits the RX/TX speed to 38,400 bps, which is fast 
enough for our purposes. These modules are highly configurable and have 
built-in Web server support. They can be configured via the Web 
interface or via telnet. Up to 256-bit AES encryption is supported on 
some versions of these modules.

The modules need regulated 3.3v power and have CMOS/TTL level interface 
line on the backside (serial) terminals. A level converter (e.g., 
MAX232) would be needed to interface with the K3's RS-232 port if the 
module is attached externally, requiring a source of 5v power. (If 
you're thinking of making a modification that is internal to the K3, the 
module can interface directly to the PIC microcontroller at up to the 
PIC-imposed limit of 115,200 bps, but that would require considerable 
hardware hacking. Maybe Wayne can put this on the wish list for a K3A or 
K4 product.)

Gus Hansen
KB0YH