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SPIN V1.2 Documentation

Note

This page is version specific. Make sure that your board version matches before reader further.

Pinout

SPIN Pinout
Figure 1: SPIN Pinout

Powerful Microcontroller made for digital power applications

The main element of the spin board is the powerful STM32G474 microcontroller.
It is meant to be used for digital power applications, and has complex and versatile analog peripherals, that can be paired with digital PWMs signals.
Aside from the microcontroller there are two buttons.

  • Reset RST – Reset the board
  • Button BTN – Connected to PC14, can be used for user-defined applications

Pressing both buttons simultaneously resets the microcontroller into RECOVERY mode, allowing safe reprogramming even if the device is unresponsive.

Microcontroller
Figure 2: Microcontroller

Onboard LEDs - Intuitive silkscreen

Two LEDs are present onboard.

  • PWR LED indicates power presence.
  • User LED connected to PA5 can be used for application development.

Note

The User LED can be disconnected via the onboard solder jumper if PA5 is required for other purposes.

Tip

A dim or flickering PWR LED may indicate insufficient or unstable power supply.
If the SPIN board is mounted on a power shield, check the upstream source for issues.

Silkscreen marking

  • is squared for GND pins
  • and round for any other signal.

LEDs
Figure 3: LEDs

Native USB support

The onboard USB-C port supports both microcontroller programming and serial communication, and is protected against electrostatic discharge.

USB
Figure 4: USB

Debugger port

This connector allows to connect an STLINK debugger.
Having a dedicated debugger permits advanced tracing, and using breakpoints in the code.

STLink interface
Figure 5: STLink interface

Recovery Mode

The SPIN board has a RECOVERY mode. This mode permits to restore a known to work program, when the board is stuck.
In recovery mode, flashing the board is not different from a regular flash.

There are 3 ways to enter recovery mode.

Pressing simultaneously BTN and RST will reboot the board in RECOVERY mode.

Connecting to the serial port at 1200Baud will trigger a reboot callback that will place the microcontroller in recovery mode.

  1. Drive PC14 high in software
  2. Trigger a software reset

Setting PC14 pin to high state, will load a small onboard capacitance, similar to the pressing action on the BTN button.