ST Microelectronics Discovery F407VG

The 32L4R9IDISCOVERY Discovery 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 Discovery 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.

ST Discovery L4R9I

St Microelectronics Discovery L4R9I. Copyright

Pin Mapping

ST Discovery L4R9I Pin Map

ST Discovery L4R9I official manual is available here

Flash Layout

The internal flash of the ST Discovery L4R9I is organized in one block divided in 256 pages of 2Kb each. The flash memory address starts at 0x8000000 and can be read and written from a Zerynth program using the internal flash module.

Device Summary

  • Microcontroller: STM32L4R9AII6 Arm®-based
  • Operating Voltage: 3.3V
  • Input Voltage: 5V
  • Flash Memory: 2Mb
  • SRAM: 640-Kbyte RAM
  • Digital I/O Pins: 65
  • Analog Input Pins (ADC): 6


32L4R9IDISCOVERY is designed to be powered by the +5 V DC power supply. It is possible to configure the 32L4R9IDISCOVERY to use any of the sources listed in the official manual;

By Default, 32L4R9IDISCOVERY is powered through USB STLINK connector CN13, JP4 header has a jumper on STLK, and SW1 is placed in ON position to allow debug and program features.

Connect, Register, Virtualize and Program

The ST Discovery L4R9I Programming port is connected to the ST-Link uploader creating a virtual COM port on a connected computer. To recognize the device, Windows machines requires drivers that can be downloaded from the ST download page, while MAC OSX and Linux machines will recognize the device automatically.

Once connected on a USB port, if drivers have been correctly installed the ST Discovery F407VG device is recognized by Zerynth Studio and listed in the Device Management Toolbar. The next steps are:

  • Select the ST Discovery F407VG on the Device Management Toolbar (disambiguate if necessary);
  • Register the device by clicking the “Z” button from the Zerynth Studio;
  • Create a Virtual Machine for the device by clicking the “Z” button for the second time;
  • Virtualize the device by clicking the “Z” button for the third time.


No user intervention on the device is required for registration and virtualization process

After virtualization, the ST Discovery L4R9I device is ready to be programmed and the Zerynth scripts uploaded. Just Select the virtualized device from the “Device Management Toolbar” and click the dedicated “upload” button of Zerynth Studio and reset the device by pressing the Reset on-board button when asked.

If also this procedure fails, try to update the ST Discovery firmware available at this link

Missing features

Not all features have been included in the ST Discovery based VMs. In particular the following are missing but will be added in the near future:

  • OTG-FS USB port;
  • SPI over the STMod+ connector;