National Instruments USB-8451 I2C/SPI Interface Device

The NI USB-8451 (Part Numbers: 779553-50 and 779553-01) is a bus-powered, full-speed I²C/SPI Interface Device. This device can be used as a means of connectivity and communication with peripheral interface devices, System Management Busses, and integrated circuits (I2C). The USB 8451 is a portable communication solution to be used with integrated circuits and consumer electronics. This Interface Device comes equipped with 8 Digital I/O lines. Each of the eight DIO lines can be programmed separately to be used as a static Digital Input or Digital Output line.  These general purpose digital lines can be utilized in a variety of applications such as I2C device configuration or toggling LEDs. The static DIO lines can also be used for monitoring or controlling digital signals. All samples of digital input lines and updates of digital output lines are software timed.

Unlike PCI interfaces, this Interface Device can be used in proximity of I2C/SPI devices, reducing l2C bus length and other problems related to noise. The NI USB 8451 is a self-sustained device and does not need an external power supply. The USB interface provides GND and +5 V to power its internal circuits. The USB 8451 National Instruments offers integrated protection against overcurrent, overvoltage, and undervoltage conditions on each SPI, DIO, and SPI CS signal. There are four SPI modes and an advanced API for custom I2C and SPi transactions. This National Instruments Interface Device comes with a USB series B receptacle and two 16-position screw terminal plug headers for I/O connectors.