Implementing an emulated universal asynchronous receiver transmitter on STM32F4 microcontroller series (AN4457)

The UART emulator is needed in applications that require more UARTs than the ones provided by STM32F4 microcontrollers.

The STSW-STM32156 firmware provides an emulated full-duplex UART which supports up to 9 data bits and up to115200 baud rates.

The STSW-STM32156 firmware also offers an example of communications between a hardware and a software UART.

For more details refer to application note AN4457.

Key Features

  • Full duplex, asynchronous communications
  • Full duplex mode up to 115200 bps
  • Data length (5 up to 9 bits)
  • Flexible GPIO use: all GPIOs could be configured as UART TX/RX


Technical Documentation

Product Specifications
Description Version Size
DB2566 DB2566: Implementing an emulated universal asynchronous receiver/transmitter on STM32F4 series 1.0 110 KB
Application Notes
Description Version Size
AN4457 AN4457: Implementing an emulated UART on STM32F4 microcontrollers 2.0 496 KB

Presentations & Training Material

Description Version Size
STM32 and STM8 embedded software solutions 6.0 2 MB


License Agreement
Description Version Size
SLA0048 SLA0048: Mix Ultimate Liberty+OSS+3rd-party V1 - SOFTWARE LICENSE AGREEMENT 4.10 86 KB

Get Software

Part Number Software Version Marketing Status Supplier Download
STSW-STM32156 1.0.0 Active ST


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