Model JI-300
I2C Host Adapter
Features
Programmable SCL clock frequency from 255Hz to 3.8Mhz (20nS steps)
Variable bus voltage from 1.50V to 5.25V (10mV steps)
Supports Master and multi-Master operation
Software selectable bus pull-up resistors (16 values including open)
USB 2.0 host interface
Switched target bus voltage available at connector
Low I2C bus capacitance (<40pF typ.)
Easy to use Graphical User Interface (GUI) software
Create custom software applications by way of either direct or
Virtual COM Port (VCP) drivers. Programming requires
no in-depth
knowledge of USB!
Includes everything needed to get started – I2C Adapter unit, I2C
cable, USB cable, and a CD-ROM containing application software and
user’s manual.
Applications
Firmware debugging and hardware troubleshooting.
Production line testing.
Equipment repair and diagnostics.
GUI Screen Shots
Main Window
Setup Menu
Add I2C Message Menu
EEPROM Read Utility
Documents and Downloads
Front View
Rear View
I2C Cable
JI-300 Specification
(pdf 143KB)
User's Manual
(pdf 724KB)
Software Demo
(zip 99K)
(4/18/08)
(4/14/08)
(4/14/08)
Note: If the window does not open,
begin by verifying that the .NET
Framework is installed. See the
JI-300 User's Manual, section 2.3,
step 4 for details.  
Software Drivers:
Programer's Interface
Document (pdf 332KB)
- Virtual COM Port
- Direct Drivers - DLLs
(2/29/08)
(2/4/08)
Questions or comments?  Please email or call:
sales@jupiteri.com
or  Ph: 949-716-0154
Jupiter Instruments                                                                                                                                                               www.jupiteri.com
Updated on 5/9/08


The JI-300 is a versatile, easy to use, PC hosted adapter used to drive I2C communications
to/from a target bus. The desktop unit can be configured to interface a variety of I2C
networks.  Bus parameters such as clock frequency, duty-cycle, setup and hold times, bus
voltage, and pull-up resistor values can be varied. JI-300’s diagnostic features including
“excessive clock-stretch”, “bus-not-free”, and “bus contention” monitoring, as well as status
reporting at the conclusion of each message transaction simplifies I2C trouble-shooting. A
Windows software application manages the setup and control of the instrument.
Communications and unit power is provided via a USB 2.0 connection.
Model JI-300
(Click for a larger view)
Jupiter Instruments
Unique instrumentation products
I2C Development Tools