Instrumenting my espresso machine with OpenTelemetry
Summary
The post documents instrumenting an ESP32-based espresso machine with OpenTelemetry and sending telemetry to ClickHouse Cloud via ClickStack. It covers on-device metrics and traces, challenges with protobuf size on microcontrollers, ensuring non-blocking I/O by partitioning tasks across cores, memory management with mutexes and queues, clock synchronization, and high-resolution shot curves, plus integrating MQTT data from Home Assistant for cross-domain observability.