Clarification on ST-LINK Requirement and Motor Pilot Runtime Communication for STM32G431CUB6

[Sujibarathi123]

Hi All,
I am currently planning a custom motor control design based on the STM32G431CUB6 microcontroller for a 3-phase inverter application.

Before finalizing my PCB design, I would like to clearly understand the firmware flashing and runtime communication possibilities, especially related to Motor Pilot and real-time monitoring.

I kindly request your clarification on the following points:

1. Is the use of ST-LINK mandatory for flashing the firmware into the STM32G431CUB6 during development?
2. Does Motor Pilot software communicate with the MCU only through ST-LINK, or can it also operate via UART?
3. For real-time monitoring of parameters such as RPM, DC bus voltage, current, and motor status using Motor Pilot, is ST-LINK compulsory? 

Your guidance will help me finalize my hardware design and production programming strategy correctly.

[STuser2]

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@Sujibarathi123 wrote:

Hi All,
I am currently planning a custom motor control design based on the STM32G431CUB6 microcontroller for a 3-phase inverter application.

Before finalizing my PCB design, I would like to clearly understand the firmware flashing and runtime communication possibilities, especially related to Motor Pilot and real-time monitoring.

I kindly request your clarification on the following points:

1. Is the use of ST-LINK mandatory for flashing the firmware into the STM32G431CUB6 during development?
2. Does Motor Pilot software communicate with the MCU only through ST-LINK, or can it also operate via UART?
3. For real-time monitoring of parameters such as RPM, DC bus voltage, current, and motor status using Motor Pilot, is ST-LINK compulsory? 

Your guidance will help me finalize my hardware design and production programming strategy correctly.

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1. Yes ST-Link is required for flashing the software. I am not sure what is the exact question.

2. Motor pilot communicates using UART not ST-Link, ST-Link only for flashing.

3. No ST Link not required, UART is required.

[Sujibarathi123]

Hello STuser2,

I am using the B-G431B-ESC1 as a reference design.
On the original ESC board, the STM32F103CBT6 (on-board ST-LINK/V2-1) provides:

SWDIO/SWCLK for programming & debugging the STM32G431

Virtual COM port (UART TX/RX) used by Motor Pilot for real-time communication (speed, voltage, current, position)

I am not using the on-board STM32F103CBT6.
I plan to remove this STM32F103CBT6. and instead use an external STLINK-V3SET / STLINK-V3MINI.

My question:

Can I connect the STM32G431 UART pins directly to the STLINK-V3SET/V3MINI “Virtual COM Port” pins and use Motor Pilot normally?
In short:
If I wire

G431 TX → STLINK-V3 UART RX

G431 RX → STLINK-V3 UART TX

GND → GND

Will Motor Pilot successfully connect and control the motor over MCP protocol (start/stop, speed monitoring, etc.)?

I want to confirm that the STLINK-V3 UART interface works the same as the on-board VCP used in B-G431B-ESC1.

[STuser2]

Yes it is possible i think.

The user manual refers to them

Electronic speed controller Discovery kit for drones with STM32G431CB - User manual

And the STLINK V3 debugger has this information

So it should be possible. 

[Sujibarathi123]

Thanks for the immediate response.