Digital Bus Communication with LabVIEW (SPI, I2C, JTAG)

[SumRunner]

I see more and more applications where SPI and I2C buses are used, and we get questions from our customers about how to access these buses with LabVIEW. I saw today that an engineer at NI developed VI's that you can use to turn any of our hardware-timed digital boards into a serial, SPI or JTAG interface, and any of our tri-state digital boards into an I2C interface.

You may know that we have a $399 device, the USB-8451, which acts as a I2C master interface or SPI:

However, with these new VI's on ni.com, you can use any of our hardware-time digital boards to do serial, SPI, or JTAG communication. A hardware-timed digital board is any board that has the circuitry to internally clock out or in a digital signal. A software-timed digital board is one that sets digital states based on software calls, but a different software call is needed each time you change the states of any of the lines. You can get a complete list of boards with hardware timed digital lines here.  In general, the low-cost, slow digitial boards are software timed and high-speed digital boards, M-series data acquisition boards, and digital waveform generators are hardware timed.

To interfae to I2C, you need a board that also supports tri-state digital lines. The 655x family of digital products support this communication.

If you have the appropriate hardware, you can find links to the various buses (along with tutorials about each bus) here.