Riki is the surface “ground station”. Positioned at the cave entrance, it acts as a local data gateway, power management hub, and control interface. It receives data from Dolphin and forwards them to the LoRaWAN transmitter.
Check out here the assembly instructions.
The Riki board also supports external modules that can receive data using a serial connection. For example, we've been using the ePaper module to print data:
This allows someone to read data from the bottom of the cave even when a LoRaWAN connection is not available: it would be needed to walk up to the cave entrance, but at least it's not necessary to enter the cave so it's much easier.