sequence.plantuml

@startuml
participant "MQTT Broker" as mqtt
participant "COAP2MQTT\nGateway" as coap
participant "mDNS Resolver" as mDNS
participant "OT Border Router" as otbr
participant "OT Child Sensor" as sed

group Initialize COAP2MQTT Gateway
  coap -> mqtt: connect to broker
  coap -> mDNS: register COAP service
  note right: serviceLabel: coap2mqtt\nserviceName: _coap._udp.\nserviceHost: sensordata.local.
end

group Initialize Openthread Sensor
  sed -> sed: set SensorID to EUI64 (MAC Address)
  sed -> sed: configure DNS resolver to mesh-local\nmulticast address ff03::1
  sed -> otbr: resolve hostname\nfor coap2mqtt service
  otbr -> mDNS: resolve
  mDNS -> otbr: response
  otbr -> sed: response
end

group Measurement Cycle
  sed -> sed: deep sleep 60s
  sed -> sed: power up i2c and sensor
  sed -> sed: take measurement
  sed -> sed: power down i2c and sensor
  sed -> sed: power up ADC
  sed -> sed: take measurement
  sed -> sed: power down ADC
  sed -> coap: PUT sensor data as JSON
  coap -> coap: parse JSON payload
  coap -> mqtt: publish sensor data
  note left
    topic for each metric: 
    openthread/[SensorID]/[metric]
  end note
end

@enduml