ST Microelectronics is a semiconductor company that has seen a huge boom among researchers and embedded enthusiasts alike (I think I fit into both categories). They have been extremely successful with their very expansive lineup of products, especially the Nucleo series. This success could be attributed to a few reasons.

  1. High affordability
  2. Higher clock speeds (in kHz range!), flash memory (up to 2M), and flexibility than other MCU boards in the same price range
  3. Capability to run RTOSes and be a part of the popular ROS ecosystem
  4. Compatibility with a large number of products, including Arduinos (see Figure 1)
Figure 1: Some of the ecosystems most Nucleo boards can work with

Nucleo boards come in three broad flavors: Nucleo 32, 64, and 144 (these have nothing to do with the MCU size of operands) which are based on the number of pins on the onboard MCU, and more importantly, the form factor of the board. These sizes are similar to the Arduino Nano, Uno, and Mega, respectively.

The Nucleo board comes in three flavors

These flavors, since they decide the MCU family, also ultimately dictate the kind of tasks the board is capable of.

A guide to application-oriented family distribution (source:

If one opens an electronics online store and looks for STM32 Nucleo Boards, they will realize that the codes associated with each board seem like imparsable (if that’s a word) strings. These “codes” actually contain a lot of information that might come handy.

A quick guide to understand STM32 codification across all flavors.

Note that the flavor can easily be determined by the pin count (position “Z”), rather than from the MCU’s family (position XX), as there are often boards in the same family but different pin counts (take F446RE and F446ZE).

ST Microelectronics also provides very extensive documentation for a variety of matters relevant to the purchase, programming, and operation of the Nucleo board. The list might be daunting at times, so it has been represented below, with almost every main kind of documentation laid down alongside the purpose thereof.

Product Specification: Databrief 
(eg DB3171 for Nucleo-144 boards)​
Short document on main features and product lineup and differences found among them; no technical know-how​
Nucleo User Manual 
Broad (and expansive) Document on the entire form-factor flavor (32, 64, or 144); basic things and aimed at getting started​
Nucleo MCU family User Manuals 
(eg. UM2407 for STM32H7)​
Not available for all families; Specific and Detailed
Product Specification: Datasheet 
(eg. DS12110 for STM32H74x)
Detailed Pinout of MCU; Overview of functionalities; Characteristics and Operating Conditions​
Reference Manuals 
(eg. RM0433for for STM32H7, 3k pages)​
Very detailed development guide, extensive information on how to use peripherals (eg. SPI, I2C), registers etc.​
Programming Manuals 
(eg. PM0253for Arm Cortex-M7 in STM32H7)​
Targeted at system-level software devs, guide to using assembly language​
Technical Notes, Application NotesSpecific for some peripheral on a board, or applications like motor control​
Table showcasing main documents useful during an STM32 project workflow

Hope this serves to be a good primer and an introduction to the STM32 ecosystem! Feel free to reach out for any help, down in the comment section.


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