This is quick and dirty device to measure waste level in undergraund tank (actually level of shit). It is build with Heltec esp32 LoRa board and hc-sr04 sonar. To connect hc-sr04 to esp32 were used 5v-3v level shifter. To smooth measurements were used QuickStats lib and median. Measurements and heartbeats transmits by LoRa to LoRa-mqtt bridge https://github.com/imelekhin/LoRatoMQTT