The STM32F407 is a high-performance microcontroller developed by STMicroelectronics based on the ARM Cortex-M4 core. With its high processing power, rich peripheral set, and extensive support tools, the STM32F407 is commonly used in a wide range of embedded applications including industrial automation, robotics, IoT devices, wearables, and more.
Key Features of STM32F407
Here are some of the key features that make the STM32F407 a popular choice for many embedded projects:
- High-performance ARM Cortex-M4 core running at up to 168 MHz
- Up to 1 MB of flash memory and 192 KB of SRAM
- Extensive peripheral set including Ethernet, USB, CAN, UARTs, ADCs, DACs, timers, DMA, crypto engine, RTC, etc.
- External memory interface for SDRAM/SRAM and NAND flash support
- Rich communication interfaces like SDIO, FSMC, Camera, Audio, Crypto
- Advanced debugging/programming via SWD, JTAG, embedded trace
- Variants with different package options, temperature ranges, and security features
- Free, open-source development tools and software libraries
Processing Power
The STM32F407 is based on the high-performance ARM Cortex-M4 32-bit RISC core operating at a frequency of up to 168 MHz. The core implements the ARMv7E-M architecture with DSP extensions, providing excellent processing efficiency and power. The Cortex-M4 is a popular choice for advanced control, multimedia, and connectivity applications requiring significant processing capabilities.
For software development, the chip supports efficient debugging and profiling tools. It includes a Memory Protection Unit (MPU) for operating system support and has single-cycle multiplication and hardware divide instructions for optimized DSP performance.
Memory Resources
The STM32F407 provides a good amount of both flash and RAM to meet the needs of complex embedded applications.
It has up to 1 MB of flash memory for storing code and data. The flash implements read-while-write support for high performance. There is also an option for 256 KB of one-time programmable memory for applications requiring data write protection.
For RAM, the chip includes up to 192 KB of fast static RAM. This provides enough runtime data storage and workspace for many demanding applications. The flexible External Memory Controller allows adding more external memory like SDRAM, SRAM, or NAND flash if needed.
Extensive Peripherals
One of the highlights of the STM32F407 is its extensive peripheral set integrating many communication, control, timing, audio, safety, and security interfaces commonly needed in embedded designs.
For connectivity, it includes multiple UARTs, I2C, full-speed USB 2.0, Ethernet MAC, SDIO, CAN 2.0B, and more. High-resolution ADCs and DACs are provided for analog interfacing. There are many general purpose timers including advanced control timers for motor control applications.
The external memory interface allows easy connection of external memory chips like SDRAM, SRAM, and NAND flash. Other notable peripherals are the camera interface, crypto/hash processor, RTC, 12-bit D/A converter, and hardware JPEG codec.
Overall, the rich set of integrated peripherals in the STM32F407 minimizes the need for external components and helps accelerate development.
Tools and Software Support
STM32F407’s popularity among embedded developers is also due to the extensive tools and software support ecosystem around it.
The STM32CubeF4 firmware package from STMicroelectronics provides a convenient way to get started quickly with example code and drivers for the peripherals. There are also many open source libraries like STM32F4xx HAL from ST, libopencm3 from Gareth McMullin, and STM32F4 from Texas Instruments.
For development environments, choices include the System Workbench for STM32 IDE based on Eclipse, STM32CubeIDE which combines CubeMX and SW4STM32, IAR EWARM, Keil MDK-ARM, free Arm Mbed Studio, and various IDEs supporting GCC toolchains.
Debugging tools like ST-LINK, J-Link, and OpenOCD allow programming the flash memory and provide JTAG and SWD interfaces. The STM32 ecosystem is well supported by third party suppliers with various add-on boards, debugging probes, and code generation tools.
Power Saving Features
For battery-powered and energy-sensitive applications, the STM32F407 has multiple power saving features:
- Flexible voltage range from 1.7V to 3.6V
- Multiple low-power modes: Sleep, Stop, Standby, Shutdown
- Wakeup pin to trigger from low-power modes
- Backup SRAM with battery input retains data in low power modes
- Voltage scaling and clock gating to reduce power
- Advanced control timers enable PWM mode for low-power motors
These capabilities allow developers to optimize power consumption for extended battery life.
Security Features
For applications requiring secure handling of sensitive data, the STM32F407 provides hardware security features like:
- Flash memory with Error Correction Code (ECC) and readout protection
- Firewalls to partition memory and peripherals into secure and non-secure regions
- True Random Number Generator (TRNG) for encryption algorithms
- One-Time Programmable memory for secure key storage
- Cryptographic coprocessor for AES, DES, SHA-1 functions
Several variants like the STM32F407G with higher security certification levels are available when needed.
Package Options
The STM32F407 is available in a range of surface-mount package options to suit different application requirements:
- LQFP100: Low-profile 100-pin package, small footprint
- LQFP144: Thin 144-pin package, high integration
- LQFP176: Feature-rich 176-pin version
- UFBGA176: Ultra-compact ball grid array, 176 pins
- LQFP208: Integrated LCD driver, large number of I/Os
The package size ranges from about 10x10mm for UFBGA176 up to 25x25mm for the larger LQFP variants. Smaller packages are useful for compact wearable or handheld designs while larger ones provide more I/O pins and flexibility.
Temperature Ranges
The STM32F407 is available in commercial and extended temperature range options:
- Commercial temperature -40°C to 85°C
- Extended temperature -40°C to 105°C
- Automotive-qualified grade -40°C to 125°C
The industrial temperature range allows using the chip in harsh environments like industrial automation, robotics, automotive, or outdoor systems. Automotive grade devices undergo more stringent qualification testing.
Applications of STM32F407
With its high performance, rich feature set, and extensive support ecosystem, the STM32F407 microcontroller is commonly used across a wide variety of embedded systems applications including:
- Industrial Automation: Programmable logic controllers, human-machine interfaces, servo motor control, sensors, etc.
- Robotics: Service robots, industrial robots, UAVs, autonomous vehicles, etc.
- Internet of Things (IoT): Wireless sensor nodes, home/building automation, energy meters, etc.
- Consumer Electronics: Digital cameras, audio systems, tablets, fitness trackers, etc.
- Medical Devices: Diagnostic equipment, infusion pumps, health monitors, etc.
- Automotive Systems: Auto infotainment, telematics, body control modules, EV charging, etc.
Overall, the combination of high computing performance, low power consumption, and rich connectivity makes the STM32F407 microcontroller an ideal choice as the embedded processor across a diverse set of applications and market segments.
Getting Started with STM32F407
Here are some tips on how to get started with using the STM32F407 for your embedded design projects:
- Pick a starter development board like Nucleo-F411RE or Discovery kit featuring STM32F407 chip
- Install one of the many IDE options – System Workbench, STM32CubeIDE, IAR EWARM, etc.
- Go through code examples in firmware packages like STM32Cube
- Learn using the peripherals by writing simple demos for LED, button, UART communication, etc.
- Check out the user manual and reference manual for your specific STM32F407 variant
- Learn to debug your code using on-chip debugging via SWD interface
- Find open source libraries, drivers and example code on GitHub, forums, STM32 communities
- Use extension boards (shields) to add connectivity, sensors, displays, etc.
- Consult datasheets and application notes when designing interfaces to other hardware
With its ease of use, strong community support and the extensive documentation resources, the STM32F407 is an excellent choice for learning ARM Cortex-M embedded development.
Conclusion
The STM32F407’s high performance 32-bit CPU, large memory resources, extensive peripherals, robust ecosystem support and optimized power consumption make it a versatile microcontroller suitable for a wide range of embedded systems and IoT applications. With numerous options for packages, temperature ranges, and security features, developers can select the right configuration matching their design needs.
Overall, the STM32F407 provides an outstanding combination of features, flexibility and value that makes it one of the most popular ARM Cortex-M4 based microcontrollers on the market today.
