First published: 2026-10-02Last updated: 2026-10-10

References

This page lists the primary sources that this book refers to. The content at each link is as of the time of writing (October 2026).

OpenTelemetry specifications

OTLP Specification: The specification that defines the OTLP transports, the protobuf and JSON encodings, the responses that qualify for a retry, and partialSuccess
opentelemetry-proto: The protobuf schema for OTLP. The hand-written encoder in this book follows the field numbers in v1.11.0
Metrics Data Model: How the data model treats gauge, cumulative sum, and StartTimeUnixNano
Logs Data Model: The timestamps and severity of log records
Deployment environment: The semantic convention for the resource attribute deployment.environment.name

OpenTelemetry Go: The official documentation for the Go API and SDK
opentelemetry-go: The Go SDK repository
go.opentelemetry.io/otel/sdk/metric: The metrics SDK
otlpmetrichttp: The OTLP/HTTP metrics exporter
go.opentelemetry.io/proto/otlp: The Go types generated from the OTLP protobuf
OpenTelemetry Collector: The official documentation for the Collector
opentelemetry-collector-contrib: The Collector distribution and the additional components that this book uses
resource processor: A processor that rewrites resource attributes
batch processor: A processor that groups data into batches before it sends them

open-telemetry/community#2160: The issue that proposed a working group to build an implementation for embedded devices
Ted Young’s comment on open-telemetry/community#2160: A remark that OpenTelemetry is not designed for embedded devices
opentelemetry-cpp#2483: The issue “Add support for embedded devices?”, which asked opentelemetry-cpp to support embedded devices
Instrumenting my espresso machine with OpenTelemetry: A blog post by ClickHouse. It describes a case in which the control board of an espresso machine, which runs on an ESP32, sent OTLP
GaggiMate: The open-source control board for espresso machines that the ClickHouse case used. It runs on an ESP32
nanopb: A protobuf implementation in C for embedded devices
ESP32 Firmware to OpenTelemetry: Documentation by base14. It describes a setup that collects telemetry from an ESP32 through MQTT and a bridge

TinyGo: A Go compiler for microcontrollers and WebAssembly
tinygo-org/tinygo: The TinyGo repository
tinygo-otel-esp32: The reference implementation for this book. It contains the code shown in the text, the Collector configuration, and the Grafana dashboard
tinygo-org/tinygo#5554: The pull request that adds PSRAM support for the ESP32-S3
espradio: A driver that lets TinyGo programs use the Wi-Fi on an ESP32
lneto: The TCP/IP stack that espradio uses

protobuf-go: The protobuf runtime for Go
dynamicpb: A protobuf message type that handles schemas at run time
protojson: An implementation of the JSON mapping for protobuf
Protocol Buffers: The official protobuf documentation
Encoding: An explanation of the protobuf wire format
encoding/json: The JSON package in the Go standard library
crypto/rand: The package for cryptographic random numbers in the Go standard library
golang.org/x/sys/unix: Go bindings for Unix system calls

RFC 4330: Simple Network Time Protocol (SNTP) Version 4
MQTT: The messaging protocol that the base14 case uses between the device and the bridge

M5Stack CoreS3: The product documentation for the device that this book uses
ESP32-S3: The Espressif product page
ESP32-S3 Datasheet: The ESP32-S3 datasheet
ESP32-S3 Technical Reference Manual: The ESP32-S3 technical reference manual
Wi-Fi API (ESP-IDF): The Wi-Fi API reference, which includes esp_wifi_sta_get_rssi

grafana/docker-otel-lgtm: A container image that bundles an OTLP endpoint with Prometheus, Loki, Tempo, and Grafana
Grafana
Prometheus
Loki
Tempo
Span metrics: The Tempo feature that generates metrics from spans
Docker Compose

Of the constraints that I found in the research for this book, I reported the following five to the projects on October 7, 2026.

tinygo-org/espradio#75: A report that a program connected through netlink has no way to set the clock (Chapter 8)
tinygo-org/espradio#76: A proposal for a function that returns the RSSI of the connected access point (Chapter 10)
tinygo-org/tinygo#5839: A report that on the ESP32-S3, TinyGo does not report a goroutine stack overflow as goroutine stack overflow. The program stops silently or crashes with a different error (Chapter 9)
Comment on tinygo-org/tinygo#5204: A case in which otlpmetrichttp does not build because tls.X509KeyPair is missing (Chapter 4)
Comment on tinygo-org/tinygo#3862: A case in which proto.Marshal in protobuf-go panics because (reflect.Type).MethodByName is not implemented (Chapter 5)