Demonstration and development platform based on STM32L4R9AI microcontroller



The 32L4R9IDISCOVERY kit is a complete demonstration and development platform for STMicroelectronics Arm Cortex-M4 core-based STM32L4R9AI microcontroller.

Leveraging the innovative ultra-low-power oriented features, 640 Kbytes of embedded RAM, graphics performance (Chrom-ART Accelerator), and DSI controller offered by the STM32L4R9AI, the 32L4R9IDISCOVERY kit enables users to easily prototype applications with state-of-the-art energy efficiency, as well as stunning audio and graphics rendering with direct support for AMOLED DSI round LCD display. For even more user-friendliness, the on-board ST-LINK/V2-1 debugger provides out-of-the-box programming and debugging capabilities.

Microcontroller main features

The STM32L4R5xx, STM32L4R7xx and STM32L4R9xx devices are an ultra-low-power microcontrollers family (STM32L4+ Series) based on the high-performance Arm® Cortex®-M4 32-bit RISC core. They operate at a frequency of up to 120 MHz.

- 2-Mbyte Flash memory - 640-Kbyte RAM in UFBGA169 package


Board features

  • 1.2” 390x390 pixel AMOLED round display panel with 16-million colors depth, MIPI DSI interface, and capacitive touch panel
  • On-board current measurement
  • SAI audio codec
  • ST-MEMS digital microphones
  • 16-Mbit asynchronous PSRAM
  • 512-Mbit Octo-SPI Flash
  • 2 user LEDs
  • 1 reset push-button
  • 4-direction joystick with selection button
  • Board connectors:
    • 8-bit camera
    • USB OTG FS with Micro-AB
    • Stereo headset jack including analog microphone input
    • microSD card
  • Board expansion connectors:
    • Arduino Uno V3
    • STMod+
    • PMOD
    • EXT_I2C
  • Flexible power-supply options:
    • ST-LINK USB VBUS or external sources
  • On-board ST-LINK/V2-1 debugger/programmer with USBre-enumeration capability: mass storage, virtual COM port and debug port

Board pinout

Pins Legend


You can find more details on the available pins and labels in the PeripheralPins.c and PinNames.h files.

These files can be found in:

  • ARMmbed/mbed-os repository on GitHub (up-to-date version, used with mbed CLI commands)


Arduino-compatible headers

https://os.mbed.com/media/uploads/jeromecoutant/disco_l4r9i_2020_10_22_arduino_left.jpg https://os.mbed.com/media/uploads/jeromecoutant/disco_l4r9i_2020_10_22_arduino_right.jpg

STMod+ header


mbed-os examples

These official mbed-os examples have been tested on this board:

Technical references

Known limitations

The following section describes known limitations of the platform. Note that general issues are tracked into the mbed repository available on GitHub.

 Buy Now