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Mini USB board bridges to I?C bus

Posted: 24 Jan 2005 ?? ?Print Version ?Bookmark and Share

Keywords:usb? saelig? usb-I2c/io board?

These days, USB impacts everything from memory sticks to test-and-measurement and data acquisition (DAQ), in products large and small. Here's a product that can help you use and embed USB in your next instrumentation and/or DAQ and control project.

The new interface board is now available from instrumentation supplier Saelig Co. It comprises a straightforward way to get a drop-in 12Mbps USB interface with your host PC, providing a 5-pin connector for a 90kbps I?C serial interface.

The USB-I2C/IO board not only lets you quickly connect external I?C hardware, but there are also 20 lines of user-configurable digital I/O, as well as an 8-bit wide data bus for fast FIFO transfers.

Quite small

The USB-I2C/IO measures 3-by-2.25-inches in size, letting you tuck it into almost any available corner of your design or package, where it will provide the hooks to interface to I?C components, or connect USB to I/O connections such as LEDs or switches. Of course, this little board is also a natural for I?C test fixture interfacing, and likewise for many DAQ and digital I/O tasks.

The full-speed USB interface provides your application hardware with a hot plug-and-play industry-standard connection to a PC host, thanks to the on-board Cypress Semiconductor AN2131QC USB microcontroller chip.

An AN2131QC development platform, too
What's more, this board can actually serve as a low cost USB development platform for the AN2131QC. An EEPROM enable/disable jumper lets the board be used as a development platform when coding firmware.

As you'd expect with a plug-in USB device, the board is equipped with a USB Status LED that lights on enumeration, and blinks to indicate USB traffic (it's off when suspended). A power configuration jumper also permits the USB-I?C/IO to be powered either by the USB port, or by external circuitry.

Multiple boards
The software also provides support for connecting multiple boards. This makes the USB-I2C/IO useful for multiple equipment instances, such for test fixtures, production equipment, and certain assemblages of test instruments. In that type of application, each board can be uniquely identified by the application software via a serial number.

The USB-I?C/IO board can also be configured to download its firmware upon connection to your PC, or to boot from an I?C bus. Mentioned above, an onboard I?C EEPROM is on the board, providing 16KB of storage for code or data. There's also an EEPROM Write Protect jumper that can provide protection from accidental on-board erasure.

In addition to an API (application programming interface), included are device driver, DLL, and example application software.

Saelig says its USB-I2C/IO is available for less than $80. Large volume OEM discounts are also available.

- Alex Mendelsohn

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