The STM32F401RDT6 is an STMicroelectronics ARM Cortex-M4 MCU from the STM32F4 series, clocked at 84 MHz with a single-precision FPU. That 84 MHz core speed means the part can run DSP filters and floating-point control loops without a separate accelerator — useful for motor control, audio processing, or sensor fusion where the math stays on-chip. The 384 KB Flash and 96 KB RAM give enough room for a modest RTOS, a USB stack, and a few hundred kilobytes of application code without squeezing into a smaller density tier.
Peripheral set and I/O budget
Fifty GPIOs in the 64-LQFP package give reasonable headroom for a mixed-signal board with a parallel LCD, keypad matrix, and a few external peripherals. The connectivity block includes USB OTG (host or device), two SPI, three USART, two I²C, SDIO, and I²S — enough for a sensor hub or a fieldbus gateway. On-chip data converters are a single 12-bit ADC with 16 channels, so if you need a DAC or a second ADC, you budget external parts.
Industrial temperature range — where it fits
It belongs in outdoor telecom enclosures, factory-floor controllers, engine-bay-adjacent electronics, and HVAC systems.
ST lists the STM32F401RDT6 as Active.