ARDUINO BASED ICOM   K9JM CI-V ROUTERGremlin in the ham shack

James Michener
16851 Aileen Way
Grass Valley,  CA 95949-7338
United States

about me

Do you have a Gremlin in your ham shack?  Want to keep the Icom PW-1 from blowing up when using a logger or contest program?   Eliminate unusual behavior of your Icom CI-V bus while under computer control?  Use a CI-V Router!

This box is an intelligent replacement for the ICOM IC CT-17.  It provides a USB interface to the PC and three isolated CI-V ports, with ICOM message store and forward between each of the total of four ports to prevent collisions.

CIV Interface board
front viewwith cables

The Icom CI-V bus does not work and play well when more than two items are on the bus.  This is especially true if you connect a logging program to the bus while another piece of radio equipment is trying to 'follow' an Icom Radio.  If you are an owner of an ICOM PW-1, did you know that Icom put an errata sheet in with your amplifier that tells you not to connect your transceiver and amplifier to a computer?  Here is the document.   The CI-V Router ends collisions on the bus and acts as an intelligent interface to your host computer.  Read a detailed description on how it works.

  • High speed bi-directional USB interface to host computer.  Supports Windows, Linux, Mac.
  • Three isolated CI-V ports
  • Powers off of USB or an external power supply
  • Bypass relays disconnects router when powered down.
  • Eliminates collisions and erratic behavior of the ICOM CI-V bus
  • Provides ICOM address translation between ports.
For more information, read the User Guide.  To acquire the lastest software, both source code and "pre-built" easy to download code,  click on the Software download link below.

CI-V Router USER GUIDE  (rev date Feb 2015) for old Version 1.10 Software
CI-V Router USER GUIDE (rev September 2016) for Current Version 1.13 and 1.12 Software
Software download
Arduino Drivers - unzip the drivers and point windows to that folder.
Arduino CI-V through hole shield assembly instructions
One page "flyer"
K9JM Windows Command Line CI-V Message Sniffer
OmniRig User Guide
ACOM Amplifier Users
User comments posted on PW-1 Yahoo Group.
STL format 3D printer box for surface mount version router

Currently selling in two forms,  a full up router, assembled and tested for $160 or just the CI-V Router board assembled and tested for $50, the user can source the other elements.  For details read the User Guide.  Standard shipping is USPS Priority Mail Small Box with delivery confirmation ($6.55).

International orders:  Contact me. Do NOT order with the "Buy Now" below.  Only CI-V interface boards are shipped internationally, and shipping costs vary with county.  International payment is best done through PayPal.

Thirty day unconditional warranty,  if you are unhappy for any reason, send everything without modifications back and get your money back.  Arduino warranty applies to the Arduino board.

Icom IC-7300, IC-7850 and 7851 and IC-7610 owners please read this

Current stock status:   
Full Routers: In Stock
    CI-V Interface board: In Stock

NOTICE:  December 23, 2017:  If you are building your own router.... in some recent Atmel processor chips I have seen the factory default value of EEPROMs  being 'random' values.  This can confuses the software.  To fix this, go into the configuration  (boot with pin 53 to ground, use PuTTy @115200 baud rate) and do a item 13 - reset to factory default.   See manual for details. 

OUT of state orders (non-California):

Full CI-V Router: 
Arduino Mega2560 board,
CI-V Router Interface board,
USB Cable,
Power Supply, 
Case    assembled and tested

CI-V Router Interface board ONLY
assembled and tested

Orders within the state of California - (includes California Sales Tax):

Full CI-V Router: 
Arduino Mega2560 board,
CI-V Router Interface board,
USB Cable,
Power Supply, 
Case    assembled and tested

CI-V Router Interface board ONLY
assembled and tested

Some more photos:

Being an Arduino based product , it is easy to customize the CI-V router to do other things in your shack!  It is trivial to make CI-V router into a band decoder to select antennas and or band filters. Some notes are available.  Full CI-V routing source code is available.  If you want to read about my own tricked out CI-V router, read this write up.


Keep in mind,  this is a hobby for me, it is not my day job.  If this sells beyond any reasonable expectations, I might make about five cents per hour for my time. :->

====>>> NEWS <<<====
1.) Icom released new firmware in May 2015 for their 7600 and 7800/785X radios.  These radios now supports two commands (0x25 and 0x26) for directly reading the main and sub receiver  frequency, mode and bandwidth.   There are at least three software packages that supports these new commands,  N1MM+,  Ham Radio Deluxe and DX Commander.  More are being added daily.   The router software versions 1.11 and earlier assumes that these new commands are invalid and will not forward them.  Using the new Icom firmware with new versions of PC software which supports these new commands will not work with old version of the K9JM router software.  Please update router firmware to version 1.13.  
Software download

2.) Version 1.11 Router added new features.  There are no changes to the core routing portion of the code.  There are several new configurable features.   There June 2015 User Guide covers these changes.
User Guide update that details these new features


copyright (C) 2016 James A Michener K9JM
September 20, 2016
Prices subject to change without notice.

I would like to thank Sir James Abraham, W6EB, for beta testing and providing constant feedback and the loan of a second Icom XCVR for testing.   Also thank Bill N3RR and Dennis K6DEN for their testing the Acom interface.

Units are available for loan to DXpeditions for credit upon request.