Ever wondered about the heart that beats within your quadcopter? That's the flight controller MCU, a tiny but mighty brain responsible for its stability and agility. Let's explore the different generations of MCUs used in flight controllers, from the pioneering F1 to the lightning-fast H7.

Unveiling the MCU: The Central Processing Unit

Flight controllers rely on microcontrollers (MCUs) from the STM32 family, developed by STMicroelectronics. These MCUs are essentially miniaturized computers, encompassing a processor core, memory, interfaces, and more. They act as the central processing unit, executing firmware like Betaflight and interpreting data from sensors to maintain smooth flight.

Generations of Flight Controller MCUs

The STM32 family boasts various series of MCUs, each with distinct features. Let's embark on a journey through some of the most prominent generations used in flight controllers:

F1 Series (2007): This series marked the dawn of flight controller technology. The NAZE32, powered by the STM32F103CBT6, was among the early pioneers. While now considered obsolete for Betaflight (support discontinued in 2017), it played a crucial role in shaping the future.

F3 Series (2012): Offering higher clock speeds and cycle times, the F3 series ushered in a new era. Popular MCUs like the STM32F303CCT6 propelled flight controllers to new heights. Betaflight support ended in 2017 with version 4.0.

F4 Series (2011): Surprisingly, the F4 series predates the F3. Offering even faster speeds and cycle times, it further enhanced flight performance. MCUs like the STM32F405RGT6 and STM32F411CCU6 are still popular options (eg. AIO F4 flight controller).

F7 Series (2014): Boasting core speeds of up to 216MHz and larger flash sizes, the F7 series pushed the boundaries. MCUs like the STM32F722RET6 with its 512Kb flash and 5 hardware UARTs enabled advanced features (eg. F722 mini flight controller) .

H7 Series (2017): Representing the latest generation, the H7 series delivers even greater performance. With clock speeds reaching 400MHz, it offers a significant leap in processing power. MCUs like the STM32H743VI with its 1MB flash and 2MB external RAM are the new benchmark.

Inverted vs. Non-Inverted Serial Ports

Interestingly, the F3, F7, and H7 series MCUs possess a unique feature: the ability to invert serial signals. This simplifies the handling of signals like SBUS and S.Port, enhancing connectivity and functionality. In contrast, F1 and F4 MCUs require external inverters, adding complexity to the design.

Exploring the Future of Flight Controller MCUs

As technology continues its relentless march forward, we can anticipate even more powerful and efficient MCUs for flight controllers. Higher processing speeds, larger memory capacities, and improved integration with onboard sensors will pave the way for even more remarkable drone capabilities.

By understanding the different generations of flight controller MCUs, we gain a deeper appreciation for the technological advancements that have revolutionized the world of drones. As we look toward the future, the possibilities for flight seem endless.