This is a sensitive single-axis seismometer capable of detecting earthquakes from around the world.  In some frequency bands it has sensitivity close to professional instruments.  Another team of developers designed this device, which is called Yuma.  I built several of them for experimentation.  

I also built a custom data acquisition system to stream measurements over the network in real time.  The sample rate is precisely locked to UTC time using a GPS-disciplined oscillator.  It runs on the Beaglebone Green using both the real-time PRU coprocessor and Linux processes running on the CPU.

An older page with construction details is available here.

Live data from Bend, Oregon is available here.