v0.1.0

ex_drone v0.1.0 Release Notes

Release Date: 2026-06-10

BEAM-native drone control for Elixir and Erlang. Fly, monitor, and simulate programmable drones using supervised processes, telemetry, and missions.

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What's New

This is the inaugural release of ex_drone, a safety-first drone control library built on OTP principles.

Core Modules

Module	Purpose
Drone	Public API — connect, fly, query, disconnect
Drone.Vehicle	GenServer per drone, supervised by Drone.Supervisor
Drone.Adapter	Behaviour for pluggable adapters
Drone.Adapters.Sim	In-process simulator — no hardware needed
Drone.Adapters.Tello	DJI Tello UDP adapter
Drone.Command	Struct constructors for all Tello SDK commands
Drone.Safety	Pure validation pipeline — altitude, distance, battery, geofence, allowlist
Drone.Safety.Policy	Presets: default/0, indoor/0, unrestricted/0
Drone.Safety.Geofence	Circle and polygon geofencing
Drone.Geometry	Shared position math (move_delta, rotate_yaw, flip_delta)
Drone.Telemetry	:telemetry event helpers
Drone.Mission	Command sequence DSL
Drone.Error	Error type helpers
Drone.Supervisor	DynamicSupervisor for vehicle processes
Drone.Application	OTP app entry point

Features

• Simulator-first design — all APIs testable without hardware
• Safety pipeline — every command validated before reaching the drone
  • Command argument validation (distance 20-500cm, degrees 1-3600, speed 10-100cm/s, hover >0s)
  • Mode enforcement (idle → SDK mode → flying → land/emergency)
  • Allowlist support, altitude/distance/battery limits, geofence
  • Emergency commands bypass all safety checks
• Dry-run mode — validate missions without flying
• Flight time simulation — query(:time) returns cumulative motor-on seconds (matches real Tello)
• Battery simulation — configurable drain rates, always reported as integer
• Failure injection — test error handling with failure_rate and fail_commands
• Position tracking — x, y, z, yaw with proper heading-aware math
• Telemetry events — [:drone, :command, :start/stop], [:drone, :safety, :reject], [:drone, :connect], [:drone, :disconnect]
• Geofencing — circle and polygon boundaries
• Mission DSL — script command sequences with error-early semantics

CI/CD Pipeline

7-job pipeline on GitHub Actions:

1. Lint — format check, unused deps, credo strict with ex_slop
2. Test matrix — Elixir 1.17-1.20 × OTP 26-29
3. Coverage — 90.2% (threshold: 70%), coveralls upload
4. Security — sobelow scan
5. Dialyzer — type checking
6. Docs — mix docs build (html + epub)
7. Release gate — publishes to Hex.pm on merge to main

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Bug Fixes (from code review)

ID	Fix
F-01	Command argument validation — reject out-of-range values with {:error, :safety, reason}
F-02	Battery always reported as integer (trunc/1)
F-04	Graceful {:error, :not_connected} for unknown drone names
F-06	Drone.Error.safety/1 used throughout Safety module (was inline tuples)
F-08	Tello parser handles negative numbers (-45)
F-09	Policy.new(unrestricted: true) no longer crashes
F-10	Drone.connect/2 accepts %Policy{} struct directly
Telemetry	terminate/2 emits adapter key (:sim/:tello), not raw module name

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GitHub Issues Resolved

#	Title	Resolution
#33	Command range validation	F-01: Safety.check validates args before policy
#38	Error module unused	F-06: Drone.Error adopted throughout
#39	@type drone too broad	Narrowed from atom() | pid() to atom()
#40	Parser negative numbers	F-08: Regex handles -?\d+
#41	Policy.unrestricted crash	F-09: Fixed preset construction
#42	Policy struct not accepted	F-10: connect/2 accepts %Policy{} or keyword
#43	Tello defaults duplicated	Centralized in Connection.default_*() accessors
#44	Vehicle.child_spec dead :id	Simplified to constant __MODULE__
#45	query(:time) returns command count	Now returns flight_time_seconds
#47	Weak implementation-detail tests	Strengthened with state assertions
#48	Documentation issues	All resolved (see below)
#49	Stale metrics, aspirational claims	Removed, corrected
#50	Dead code and duplication	Removed duplication, extracted shared modules

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Documentation Updates

File	Change
CHANGELOG.md	Comprehensive v0.1.0 Added/Changed/Fixed
README.md	Added Geometry to architecture, verified no stale claims
docs/architecture.md	Added Geometry module, updated command pipeline diagram
docs/safety.md	Added %Policy{} struct usage example
docs/simulator.md	Added flight time simulation section
docs/tello.md	Replaced FakeServer reference, documented Connection.default_*()
mix.exs	Added Mox dep, excluded FakeTelloServer from coverage

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Quality Metrics

Metric	Value
Tests	253 passing
Coverage	90.2% (threshold: 70%)
Credo	strict, 0 issues
Dialyzer	clean
Compiler	--warnings-as-errors clean
Format	checked
Source files	19 modules, 2,565 LOC
Test files	21 files, 2,434 LOC

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Coverage by Module

Module	Coverage
Drone	96.5%
Drone.Adapter	100%
Drone.Adapters.Sim	97.4%
Drone.Adapters.Sim.State	100%
Drone.Adapters.Tello	39.1%*
Drone.Adapters.Tello.Connection	83.3%
Drone.Adapters.Tello.Encoder	100%
Drone.Adapters.Tello.Parser	88.8%
Drone.Command	100%
Drone.Error	100%
Drone.Geometry	100%
Drone.Mission	95.8%
Drone.Safety	94.1%
Drone.Safety.Geofence	100%
Drone.Safety.Policy	100%
Drone.Supervisor	100%
Drone.Telemetry	91.6%
Drone.Vehicle	89.3%

* Tello adapter requires hardware/UDP; integration tests run separately.

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Minimum Requirements

• Elixir ~> 1.17
• Erlang/OTP 26+
• Dependency: telemetry ~> 1.0

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Known Limitations

• Tello adapter requires a physical drone and Wi-Fi connection (no mock UDP layer yet)
• Tello adapter coverage is low (39.1%) because connection tests need a real drone
• safe_to_retry?/1 in Drone.Command documents retryability but no retry mechanism exists yet
• Mission run/2 blocks the calling process — no async mission execution

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Upgrading

This is the initial release. Add to your mix.exs:

def deps do
  [
    {:ex_drone, "~> 0.1.0"}
  ]
end

Then:

mix deps.get

See Getting Started for the full walkthrough.