A curated list of free tools and resources for embedded, firmware, and hardware development.

PCB design, debugging, simulation, CI, IoT backends, RF, TinyML, and more.

 

📑 Table of Contents

• PCB Design & EDA
• Debug Probes & JTAG/SWD
• Simulation
• Logic Analyzers & Signal Tools
• CI / Build / Firmware Testing
• Free IoT / Cloud Backends
• Free Firmware OTA Hosting
• Enclosure & 3D Printing
• RF / Antenna Tools
• Component Search & Datasheets
• Power Supply & Regulator Design
• RTOS & Bootloader Frameworks
• Code Quality, Static Analysis & Testing
• TinyML / Edge AI
• Power Profiling & Current Measurement
• Parts Inventory & BOM Management
• Wireless Pre-Compliance & Regulatory Lookup
• Hardware Version Control & Collaboration
• Free Courses & Learning
• Component Sourcing & Free Samples
• Contributing

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📐 PCB Design & EDA

Tool	What's Free	Limits / Notes
KiCad	Entire suite, no account, no usage cap	Open-source (GPLv3), offline, up to 32 copper layers. No commercial restrictions.
EasyEDA	Standard Edition: schematic, layout, SPICE sim, manufacturing export	Cloud-only, tied to JLCPCB. Good for quick projects; weaker for complex boards.
Altium CircuitMaker	Full Altium-engine EDA	Windows-only, cloud-hosted projects, ~5 private projects max.
LibrePCB	Fully free and open	Smaller community than KiCad, but unrestricted.
Quilter (AI routing)	Free tier, full routing engine	Add-on for KiCad/Altium/Cadence, not a full EDA suite. Free-tier designs may be used for model training; avoid proprietary designs.

🔍 Debug Probes & JTAG/SWD

Tool	What's Free	Notes
OpenOCD	Free, open-source	Software side of most JTAG/SWD debugging; works with many adapters.
Black Magic Debug	Free firmware for compatible probes, or run standalone	Plug-and-play GDB server; no separate host software needed.
ESP-Prog	Open-source design files; ~$15 hardware	Espressif JTAG + auto-flash board for ESP-IDF work.
J-Link EDU / EDU Mini	Free for non-commercial use only	Real SEGGER hardware/software. Check licensing before commercial use.
PlatformIO Unified Debugger	Free with PlatformIO Core	Debugging across ~20 probes (ST-Link, J-Link, ESP-Prog, Black Magic, etc.) from one interface.

🌀 Simulation

Tool	What's Free	Notes
ngspice / KiCad's built-in SPICE	Free, open-source	Circuit-level simulation in KiCad's schematic editor.
Falstad Circuit Simulator	Free, browser-based	Good for quick intuition and teaching, not design verification.
Wokwi	Free tier, browser-based	Simulates ESP32/Arduino/Pi Pico with virtual peripherals before hardware is available.
Renode	Free, open-source	Full system simulation (CPU, peripherals, network) for firmware testing without hardware.

📈 Logic Analyzers & Signal Tools

Tool	What's Free	Notes
PulseView (sigrok)	Free, open-source	GUI for cheap USB logic analyzers with UART/SPI/I2C protocol decoders.
Saleae Logic software	Free software	Requires Saleae hardware.

⚙️ CI / Build / Firmware Testing

Tool	What's Free	Notes
GitHub Actions	2,000 free CI minutes/month (unlimited on public repos)	Common choice for ESP-IDF and PlatformIO build matrices.
PlatformIO Core	Free CLI + build system	Multi-board, multi-framework builds without vendor IDE lock-in.
Wokwi CI	Free tier for CI-triggered simulation	Run simulated hardware-in-the-loop tests in GitHub Actions.

☁️ Free IoT / Cloud Backends

Service	What's Free	Limits
HiveMQ Cloud	Free MQTT broker tier	100 device connections, capped throughput.
ThingSpeak	Free tier	3,000,000 messages/year.
Adafruit IO	Free tier	Rate-limited; works well with ESP32/Arduino.
Firebase Spark plan	Free tier	Realtime DB + hosting for small device fleets.

📡 Free Firmware OTA Hosting

Approach	What's Free	Notes
GitHub Releases + raw manifest	Free within normal GitHub quotas	Host firmware.bin as a release asset and a version.json manifest. Device checks the manifest on boot and compares versions. No backend required.
JSONhost (or similar)	Free tier	Stable public GET endpoint for a version manifest if you prefer not to use GitHub raw URLs.
ESP-IDF native OTA (self-hosted)	Built into ESP-IDF	HTTPS pull with signed images and partition swap. You run the server.
Golioth / Memfault free tiers	Free tier for small fleets	Staged rollouts, rollback, and fleet observability beyond a simple manifest file.

For personal projects, a GitHub Releases manifest is usually enough. For end-user devices, plan for signing and rollback to avoid bricked updates.

📦 Enclosure & 3D Printing

Tool	What's Free	Notes
FreeCAD	Fully free, open-source	Parametric CAD for enclosures. Steeper learning curve than Fusion, no licensing restrictions.
Fusion 360 Personal Use	Free for hobbyist/non-commercial use	Common for maker enclosures. Commercial use requires a paid license.
Onshape Free Tier	Free for public documents	Browser-based collaborative CAD. Free-tier designs are publicly visible.
PrusaSlicer / Cura	Fully free	Standard slicers for most FDM printers.
Printables / Thingiverse	Free STL hosting + library	Check existing models before designing standoffs, DIN rail clips, or battery holders from scratch.

:satellite_orbital: RF / Antenna Tools

Tool	What's Free	Notes
NEC2 / 4nec2	Free, open-source antenna modeling	Wire antenna simulation (gain, impedance, radiation pattern).
openEMS	Free, open-source FDTD simulator	3D EM simulation for PCB antennas and RF structures. Heavier setup than NEC2.
SimSmith	Free	Smith chart tool for matching network design.
rtl_433 / GNU Radio	Free, open-source	SDR tooling for SubGHz/ISM-band signal decoding and analysis.

🔎 Component Search & Datasheets

Tool	What's Free	Notes
Octopart	Free search, no account for basic use	Cross-distributor search (stock, price, datasheets) across DigiKey/Mouser/LCSC.
Findchips	Free	Similar aggregator; useful when Octopart data looks stale.
DigiKey / Mouser / LCSC parametric search	Free	Each distributor's own parametric filters, often more detailed for their stock.
SnapMagic (SnapEDA)	Free symbols + footprints for millions of parts	Downloadable into KiCad/Altium/Eagle format.

⚡ Power Supply & Regulator Design

Tool	What's Free	Notes
TI WEBENCH / Power Designer	Free, browser-based	Input voltage/current requirements; get ranked TI regulator topologies with schematic and BOM.
Analog Devices ADIsimPower	Free	Same category, scoped to ADI regulators.
Battery life / capacity calculators (DigiKey tool hub)	Free	Quick runtime estimates before committing to a battery design.

🔄 RTOS & Bootloader Frameworks

Tool	What's Free	Notes
FreeRTOS	Free, open-source (MIT)	What ESP-IDF is built on. Direct access to tasks, queues, and semaphores.
Zephyr RTOS	Free, open-source	Broader hardware support than FreeRTOS alone; Linux Foundation-backed.
MCUboot	Free, open-source	Secure bootloader for signed, rollback-safe firmware updates. Pairs well with the OTA section above.

✅ Code Quality, Static Analysis & Testing

Tool	What's Free	Notes
cppcheck	Free, open-source	Static analysis for C/C++: buffer overruns, null derefs, uninitialized reads.
clang-tidy	Free, open-source	Deeper static analysis and style checks; integrates with editors and CI.
Unity / Ceedling	Free, open-source	Lightweight C unit testing for embedded; runs on-host or on-target.
PlatformIO Unit Testing	Free, built into PlatformIO Core	Same test suite on native host and real hardware from one config.
PVS-Studio free license	Free for open-source projects	Commercial-grade static analyzer; apply if your repo qualifies.

🤖 TinyML / Edge AI

Tool	What's Free	Notes
Edge Impulse	Free for individual developers	Data collect, train, deploy workflow; exports optimized C++ to ESP32/Cortex-M targets.
TensorFlow Lite Micro	Free, open-source	Inference runtime used by many TinyML tools; direct control over model size and arena allocation.
CMSIS-NN	Free, open-source	ARM-optimized NN kernels for Cortex-M.
ESP-DL	Free, open-source	Espressif inference library tuned for ESP32-S3 vector instructions.

🔋 Power Profiling & Current Measurement

Tool	What's Free	Notes
Nordic Power Profiler Kit II software	Free software (~$80 hardware)	Current measurement down to µA for validating deep-sleep claims.
Joulescope UI	Free software (hardware required)	Wide dynamic range for sleep and active-radio current spikes.
ESP-IDF power management logging	Built into ESP-IDF	Software-only estimate; not a substitute for real measurement.

📦 Parts Inventory & BOM Management

Tool	What's Free	Notes
InvenTree	Free, open-source, self-hosted	Stock control, BOM management, supplier data, and a KiCad plugin for native symbol libraries.
Ki-nTree	Free, open-source	Pulls part data from DigiKey/Mouser/LCSC/Element14 and creates InvenTree + KiCad entries in one step.
Part-DB	Free, open-source, self-hosted	Similar scope to InvenTree with KiCad integration.
PartKeepr	Free, open-source	Older, simpler option for shared hackerspace inventory.

:scales: Wireless Pre-Compliance & Regulatory Lookup

Tool	What's Free	Notes
FCC Table of Frequency Allocations	Free, official	Which bands are allowed for transmission in the US.
FCC ID Search	Free, official	Look up existing FCC IDs and certified module test filings.
FCC Equipment Authorization guidance	Free, official	SDoC vs full Certification requirements and cost implications.
Pre-compliance with a cheap SDR/spectrum analyzer	Free (software side)	Still need RF hardware (e.g. RTL-SDR), but analysis software (GNU Radio) is free. Catches obvious spurious emissions before a paid EMC lab session.

These tools help avoid surprises; they do not replace an accredited test lab before selling a product with a radio.

🔃 Hardware Version Control & Collaboration

Tool	What's Free	Notes
Git + GitHub free tier	Free	KiCad projects are plain text, so standard git diffs and PRs work for hardware too.
KiCad's built-in git integration	Built into KiCad 7+	Project history and diffing inside the KiCad GUI.
OSHWLab	Free project hosting	EasyEDA's public, forkable hardware project platform.

📚 Free Courses & Learning

Resource	What's Free	Notes
HarvardX TinyML EdX course	Free to audit	Intro course; pairs with the Arduino Tiny Machine Learning Kit.
Espressif's official ESP-IDF Programming Guide	Free, official	Authoritative ESP32 documentation.
KiCad official documentation + forum	Free	Active community; search before posting.
Interrupt (Memfault's blog)	Free	Practical firmware engineering articles on debugging, OTA, and power profiling.

🎁 Component Sourcing & Free Samples

Source	What's Free	Notes
TI Sample Program	Free samples, small qty	Business/edu email speeds approval but is not required.
Analog Devices Samples	Free samples	Similar process to TI.
Microchip Samples	Free samples	Similar process to TI.
JLCPCB new-user credit	Varies monthly	Check current promo before ordering.

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🤝 Contributing

See CONTRIBUTING.md. One row per tool, keep the "what's free" column honest, and note real limits.

Disclaimer

Free tiers, pricing, and limits change without notice. Verify current terms on the provider's site before relying on anything for production. This list excludes anything that is not a legitimate offering (e.g. abusing trial accounts or violating ToS).

License

MIT. See LICENSE.

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Contact

• Patreon: patreon.com/cifertech
• Twitter: @techcifer
• Email: CiferTech@gmail.com
• Repo: github.com/cifertech/free-embedded-dev-tools