The SeismicPi HAT is designed to allow data from all four input channels or, alternatively, from the on-board accelerometer to be outputted in realtime to a computer.
Data can be sent over a USB Virtual Com Port or the UART directly into a Raspberry Pi via the HAT connector. I.e. be used via USB, without connection to a Raspberry Pi, or mounted on a Raspberry Pi without a USB connection.
For backwards compatibility with other digitisers, the HAT can optionally output a single channel of data (channel 0).
The firmware can be updated via an SD card (see datasheet for more information).