SPI and I2C interfaces in a PXI or PXIe module that isn't FlexRio?

[MrManSplain]

I am putting together a proposal for a PXI based multi-function ATE system and now looking for a module that can provide SPI and I2C interfaces. After scouring the NI site & forums I see that NI do a couple of USB based modules that can be configured for SPI and I2C, but would like to keep it all PXI if at all possible just to keep all the DAQ HW in the one chassis for modularity. Does anyone know if there are any dedicated PXI DAQ/DIO units that can provide the SPI and I2C protocols? I figure the faster modules may be able to handle it from a dynamic/speed point of view, but do the drivers have these protocols built in? Or are my only NI options the USB modules or going for one of the PXI FlexRIO FPGA modules, with the associated additional FPGA dev software costs? The FlexRio based modules seem to be overkill functionality and cost-wise for relatively simple serial interfaces. Any advice gratefully received.

[santo_13 · Accepted solution]

Here are your options,

1. USB-845x
2. PXIe-657x
3. Any other FlexRIO/FPGA card

The order also reflects the increasing order of complexity and cost.

[MrManSplain]

Ok thank you. Its kind of what I expected but even after trawling the NI site I wasn't certain. USB-8452 it is then or maybe a suitable FTDI board. I have accepted your reply as solution.

[santo_13]

8452 has more flexibility and good API compared to FTDI alternatives, but it depends on your usage.

Note, if you use FTDI, you may get only a dll, then you need to build LV API wrappers to properly use, and it could be a pain if you aren't familiar with c dlls.

[MrManSplain]

Good info thanks. I have used FTDI boards before for bit-banging so am reasonably familiar. I think there is even a LV driver I have seen on VIPM for one series, but have also used DLLs in LV before. It was more that I wanted a satisfying one box solution if possible as modular as possible for future expansion too. But not at those prices 🙂

[crossrulz]

I am a fan of the USB-8452.  But at this point in my life, I would just use a Raspberry Pi Pico or an Arduino to do I2C and/or SPI.  The Pico can be bought for $4 and is mostly easy to program (obviously depending on how much you want in it).

I am currently experimenting in my little free time with a Pico to get a somewhat complicated digital waveform out of it.  If successful, I have plans to use it to completely replace a cRIO solution.