AT32: The Next Big Thing in Flight Controllers, or Just a STM32 Challenger?

Prepare for a major shift in the FPV landscape as the AT32 MCU redefines affordable flight controllers and ESCs. We're here to unravel this exciting innovation, comparing its performance with previous industry gold standards.

6 months ago   •   5 min read

By Alex
Table of contents

Prepare for a major shift in the FPV landscape as the AT32 MCU redefines affordable flight controllers and ESCs. We're here to unravel this exciting innovation, comparing its performance with previous industry gold standards, and revealing how it promises to slash costs while maintaining top-tier performance. If you're an FPV enthusiast, you'll want to delve into the full story of the AT32's game-changing potential.

The STM32 Problem: The Search for Cost-Effective Alternatives

The micro controller unit (MCU), the brain of flight controllers, has long been ruled by STM32 MCUs. Despite their reliability and performance, the global silicon shortage and inflation have driven up their prices, pushing manufacturers to explore cost-effective alternatives like the STM32 F4 series, such as the popular Speedybee F405 V3 stack. However, the quest for affordability has led to an exciting new player in the market - the AT32.

AT32: An Economical Powerhouse in Flight Controllers and ESC

The AT32, an MCU manufactured by ArteryTek, is not a clone or a direct replacement for the STM32. It does require some adaptations to work with Betaflight. However, its performance, features, and most of all, its affordability make it a compelling alternative for flight controllers. It's already been adopted in some of the latest ESCs, such as the Hobbywing G2 45A and 65A 4in1 ESC.

Comparative Analysis: AT32 vs. STM32 Chips

The AT32 and STM32 chips have different strengths and weaknesses, but there are several reasons why the AT32 might be seen as a better choice, particularly for certain applications:

  1. Cost: The AT32 chips are generally more cost-effective than the STM32 chips. This is a significant factor in industries where minimizing costs is crucial. In the context of Flight Controllers (FC) and Electronic Speed Controllers (ESC), the adoption of AT32 chips can lead to more affordable products for end-users.
  2. Performance: Correction, VitrodFPV kindly pointed out that I incorrectly stated that the AT32 has more performance than the stm32 F4 and F7, this is not true, the AT32 has more flash memory.  The AT32 does have a higher clock speed than the F405, but it's not faster than the F7, since the F7 uses M7 cores, and the use only M4 cores.
  3. Package size: The AT32F435 has a 6x6mm package size, which is smaller than the 10x10mm package size of the STM32F405 and STM32F722. This could be an advantage in applications where space is at a premium, such as in compact flight controllers for drones.
  4. Power efficiency: The AT32F435/437 offers a comprehensive set of power-saving modes, which meet the requirements of low-power applications.
Performance between AT32 and other STM32 mcu

Comparing the AT32F435 with the commonly used STM32F405 and STM32F722 microcontrollers.  The STM32F411 clocks 108MHz, STM32F405 does 168MHz, and AT32F435 is 288MHz. But all are using the arm Cortex M4 cores.  While the F722 runs at 216MHz, it's using Cortex M7 cores. The STM32F722 equivalent of an AT32F435 running at 288MHz would be the STM32F722 running at only about 195MHz. But it can do up to 216. So it's clear that the AT32F435 cannot outperform the STM32F722, it is better than the F405, and outperforms them in terms of cost. Additionally, its smaller package size makes it a superior alternative for tiny micro quads. This highlights the AT32's potential to revolutionize the flight controller landscape.

Getting Your Hands on the AT32

Currently, NeutronRC is the sole manufacturer offering AT32 flight controllers. They offer an AIO board powered by an AT32F435 MCU with an integrated 4-in-1 ESC running on AM32 firmware. There are different versions available depending on your ESC ratings. For those seeking an alternative, there is a different FC design that uses a larger variant of the AT32F435 chip.

AT32 Compatibility with Betaflight

As of now, AT32 flight controllers are not compatible with Betaflight, running instead on a special fork of the old Betaflight 4.3, called ATBetaflight. However, work is actively underway to extend Betaflight support to these new AT32 flight controllers. If you're keen on the latest Betaflight features, it might be best to wait for the update expected in Betaflight 4.5.

Conclusion: The AT32's Promise for FPV

While it's too early to declare AT32 as the new revolution in FPV drone technology, its potential is undeniably exciting. The AT32 flight controller presents a cost-effective alternative, introducing fresh competition within the industry and paving the way for more affordable options for everyone.

FAQ

Q: What is the AT32F435 chip?

  • A: The AT32F435 chip is a microcontroller unit (MCU) made by ArteryTek. It's based on the high-performance ARM Cortex-M4 32-bit RISC core, running at speeds up to 288 MHz. It's not a clone or a direct drop-in replacement for the STM32, but it offers comparable performance at a more affordable price. It's currently being used in some of the latest ESCs, including the Hobbywing G2 45A, 65A 4in1 ESC.

Q: What advantages does the AT32F435 chip offer over the STM32 chips commonly used in flight controllers?

  • A: The AT32F435 chip outperforms commonly used STM32 chips in flight controllers in terms of cost. It it is roughtly equivalent to the STM32 F405 but with larger flash memory and SRAM, and a smaller package size. That lower cost is what makes products using this chip more affordable for consumers.

Q: Where can I buy flight controllers that use the AT32 chip?

  • A: Currently, NeutronRC appears to be the only manufacturer offering flight controllers that use the AT32 chip. You can find their products on their website or other online marketplaces like AliExpress.

Q: Are AT32-based flight controllers compatible with Betaflight?

  • A: At the time of the article, AT32 flight controllers are not compatible with Betaflight yet. However, work is actively underway to extend Betaflight support to these new AT32 flight controllers and is expected to arrive in Betaflight 4.5.

Q: Is the AT32 chip set to replace the STM32 chip in flight controllers?

  • A: It's too early to say whether the AT32 will replace the STM32 in flight controllers. While the AT32 offers many advantages, such as cost-effectiveness and superior performance on some metrics, there are also factors to consider, such as Betaflight compatibility. It's a development that's worth keeping an eye on in the FPV community.  However, given the price to performance factor I am sure it will be here to stay, particularly to replace F411 and F405 based flight controllers.

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