For years, BLHeli_32 has been the undisputed king of electronic speed controllers (ESCs) in the FPV drone and high-performance RC world. Its smooth sinusoidal startup, robust telemetry, and reliable performance set the industry standard. However, as the community evolves, a new open-source contender has emerged, challenging the status quo: AM32.

But what exactly is the difference? And more importantly, how does hardware like the new Maxkgo 5-12S 120A/200A AM32 ESC fit into this shifting landscape? Let’s dive in.

AM32 was born from the desire for a truly open-source alternative. Forked from BLHeli_S and evolved independently, AM32 offers:

The Verdict? If you want stability and mainstream compatibility, BLHeli_32 is safe. But if you want cutting-edge features, transparency, and a future-proof ecosystem, AM32 is the clear winner.

What is AM32?

1. Introduction to AM32 Firmware

AM32 is a completely open-source firmware designed for brushless ESCs, primarily running on 32-bit microcontrollers such as STM32 and AT32. Unlike the commercialized BLHeli_32. AM32 adopts an open-source approach, allowing developers to freely compile, modify, and extend functions. With its high flexibility, wide hardware adaptation range, and significant cost advantages, AM32 has become the most discussed open-source firmware system in the FPV and multirotor fields over the past two years.

2. Background of AM32's Emergence

BLHeli_32 has long dominated the FPV industry, but its licensing model means manufacturers must pay fees for every unit of firmware and strictly adhere to the restrictions of a closed-source ecosystem. To a certain extent, this model increased the overall cost of ESCs and limited the space for some manufacturers regarding custom functions and secondary development.

In this context, AM32 emerged as an open-source firmware project, providing another path for the ESC ecosystem: no licensing fees, free modification of firmware logic, and adaptation to a wider range of hardware platforms. Its openness has enabled many small and medium-sized brands to lower hardware costs and has attracted a large number of developers and DIY users to participate in improvement and testing.

3. Technical Features of AM32

Supports Multiple Drive Protocols (DShot, PWM, FOC)

AM32 is compatible with mainstream digital and analog throttle protocols and includes the increasingly popular FOC (Field Oriented Control) mode, which makes motor operation smoother, quieter, and provides better low-speed performance.

Free Compilation / Custom Functions

Users can compile the firmware themselves according to actual needs, including: adjusting drive frequencies, optimizing startup algorithms, modifying protection logic, and adding experimental functions. This is of significant value to R&D personnel and enthusiasts.

Supports More Low-Cost MCUs

AM32 does not rely on high-end processor platforms, so it can run on a variety of lower-cost 32-bit chips. This provides manufacturers with greater hardware flexibility, allowing certain high value-for-money ESCs to enter the market at a lower cost.

4. Ecosystem Characteristics of AM32

Community-Driven, Rapid Iteration

AM32 is maintained entirely by the community. Its update cycle is fast, and function expansion is flexible; all types of developers can submit improvement proposals. This has enabled AM32 to achieve rapid growth from experimental firmware to mature application in a short time.

Mass Adoption by Small and Medium ESC Brands

Many emerging manufacturers adopt AM32 to lower firmware licensing fees in order to improve cost competitiveness, making it easier to launch product lines covering different specifications and price points.

Highly Active DIY Players

Because the firmware is open, users can flash different versions themselves, try personalized parameter combinations, and even participate in code optimization. Therefore, AM32 is very popular in the DIY modification circle, low-cost long-range platforms, and experimental drone projects.

BLHeli_32 vs AM32: What are the Differences?

Both BLHeli_32 and AM32 have become mainstream firmware systems in the current multirotor and FPV ESC market, but there are essential differences in their architecture, functions, ecosystem, and application positioning. The following content will expand on a systematic comparison from multiple dimensions to provide a more targeted reference for users with different needs.

Comparison Aspect	BLHeli_32	AM32
System / Architecture	Commercial closed-source; requires licensing; highly consistent performance	Fully open-source; free to modify and port; performance varies by vendor implementation
Throttle Protocols	Stable support for DShot150/300/600/1200	Supports DShot, PWM, and FOC; compatibility depends on porting quality
FOC Support	No FOC support; uses traditional six-step commutation	Supports FOC (experimental/vendor-optimized); smoother low-RPM performance and lower noise
Protection Mechanisms	Mature over-current, over-temperature, voltage and startup protections; proven in long-term use	Basic protections available, but consistency depends on hardware and firmware version
Motor Drive Logic	Consistent startup, stable throttle linearity, strong high-speed response	Fully customizable drive logic, PWM frequency and PID behavior
Telemetry & Peripherals	Standardized support for RPM telemetry, LEDs and buzzer; high compatibility	Telemetry and peripherals supported but implementation varies across ESCs
Stability & Reliability	Widely validated in racing, freestyle and commercial platforms	Stability depends on MCU and vendor tuning; quality varies between products
Ecosystem Compatibility	Highly compatible with Betaflight, INAV, KISS and ArduPilot	Ecosystem developing quickly; generally compatible but version gaps may affect experience
Cost / Licensing	Requires paid firmware licensing; increases ESC cost	Completely free; enables more cost-effective ESC products
Customization	Limited tuning options; core logic cannot be modified; plug-and-play experience	Fully compilable and modifiable; ideal for R&D and advanced DIY users
Target Use Cases	High-performance and commercial drones requiring consistency and reliability	Cost-sensitive platforms, long-range setups, experimental builds and DIY applications

1. Differences in Technical Architecture

BLHeli_32 is a mature commercial closed-source system

The core code of BLHeli_32 is not public, and manufacturers need to use it via licensing. This closed mechanism brings highly consistent firmware quality, standardized development processes, and stable compatibility, but it also limits the freedom of secondary development.

AM32 is completely open-source

AM32 provides complete source code, and developers can freely modify, compile, and port the firmware. Its open mechanism brings vast customization space for manufacturers and players, but actual ESC performance may vary depending on the quality of porting and tuning.

Conclusion: Closed-source firmware emphasizes consistency and stability; open-source firmware provides more freedom and scalability.

2. Functional Differences

DShot Support

Both support mainstream DShot protocols, but BLHeli_32 is more mature in terms of compatibility and stability. AM32's support capability depends on the specific hardware and ported version, and performance may vary.

FOC (Field Oriented Control) Mode

AM32 supports experimental or manufacturer-optimized FOC modes, which can gain advantages in low-speed operation, silence characteristics, and efficiency performance; BLHeli_32 currently still relies mainly on the traditional six-step commutation method, emphasizing response speed and transient performance.

Maturity of Protection Mechanisms

BLHeli_32 is configured with comprehensive and strict over-current, over-temperature, startup, and voltage protection strategies, verified by large-scale commercial use; AM32 possesses basic protection functions, but specific behaviors depend on manufacturer porting and community versions, making its maturity relatively less consistent than BLHeli_32.

Motor Drive Logic

BLHeli_32 performs stably in throttle linearity, startup consistency, and high-speed response; AM32 offers more open tuning space, allowing developers to adjust PID drive logic, PWM frequencies, etc., giving it potential advantages in specific scenarios.

LED, Buzzer, RPM Telemetry

Both support RPM Telemetry, but BLHeli_32 performs more stably in standardization and compatibility; AM32 supports more flexible peripheral definitions, but implementation methods are not entirely consistent.

3. Stability and Reliability Comparison

BLHeli_32

Having undergone years of large-scale FPV application verification, its stability has become the industry standard. Whether in racing, Freestyle, or commercial mission platforms, BLHeli_32's consistency and reliability stand out in actual use.

AM32

Stability depends on the firmware version, MCU type, and manufacturer tuning capability. High-quality implementations of AM32 ESCs can achieve good performance, but there is greater variation between different products on the market, requiring user discrimination.

4. Ecosystem and Compatibility Differences

BLHeli_32

Highly compatible with mainstream flight controller ecosystems (Betaflight, INAV, KISS, ArduPilot, etc.), and is mature and comprehensive in parameter recognition, protocol support, and debugging tools.

AM32

The ecosystem is still developing rapidly. Compatibility is generally good, but ported versions from different manufacturers may have detailed differences, resulting in an experience that is not as comprehensively consistent as BLHeli_32.

🚀 Introducing: Maxkgo 5-12S 120A/200A AM32 ESC

Why Choose Maxkgo for Your AM32 Build?

1. True High-Power Performance