Are there any (relevant) differences between ADXL345 on SPI and on USB?

There are ADXL345 boards that connect to the SPI bus with a flat flex cable:

And then there are some that have an extra RP2040 MCU and connect to USB:

I think I’d prefer the USB one because the USB cable is easier to install, I can add more than one and they’re also cheaper.

Does the USB connection introduce any kind of delay or something that might be detrimental to measurement quality?

For what it is worth, I’d prefer USB over SPI. The USB protocol does a much better job of detecting, avoiding, and recovering from errors due to line noise on the wires.



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…and the wiring might be smoother

@AndreKR These USB ADXL345 boards still use SPI. They are a RP2040 chip and ADXL345 chip on a small board that acts as a 2nd MCU for Klipper…all communicating over USB.

It just makes the SPI connection much easier because it is hardwired on the small board.