Problem with a STM32F746G-DISCO Board and an Arduino shield

[Francesco1]

Hi all,

I have an STM32F746G-DISCO board bought some years ago and I am trying to use it with a Pololu Dual VNH5019 Motor Driver Shield for Arduino (https://www.pololu.com/product/2507) to drive a DC motor.

I successfully created a TouchGFX application with a couple of buttons and a slider with which I can control the START/STOP status of the motor and the duty cycle of a PWM signal which controls its speed.

The shield uses Arduino signals D2, D4 as Motor 1 Direction inputs A and B respectively, D6 as Motor 1 enable signal and D9 as PWM signal.

All signals work correctly except D4 ( = M1INB) which from the schematic diagram of the discovery board should correspond to signal PG7. Unfortunately PG7 seems to be not available at all in the GPIO configuration panel of the board in STM32CubeMX.

I don't not if this could be a problem with the particular revision of the discovery board I have.

Unfortunately I am unable to find its revision (I bought it some years ago), but I attach a couple of photos to this post in the hope someone can help me to correctly identify it.

Any help will be appreciated.

Thanks in advance for your help.

[CYANG.1]

Hi,

What you mean "Unfortunately PG7 seems to be not available at all in the GPIO configuration panel of the board in STM32CubeMX"?

I checked cubemx for STM32F746G-DISCO, PG7 is on the map and is assigned to D4 of arduino connector. You can see the figure attached.

And you board seems a newer version, so I don't think there are limitations on the board without any comments in UM.

You could check PG7 by setting it as a normal GPIO with a square waveform and measure the signal on Arduino connector to check whether PG7 is well connected on your board.

B.R.

[Francesco1]

Hi @CYANG.1 

thank you for your reply; the pinout graphical view and table of my board are viewable in the attached screenshot; I don't know why, but pins used on the arduino connectors are not not inizialized with the names I see in your screenshot. I personalized name and funtions of only those pins needed by my application, but none of the others have names starting with "ARD_".

As you can see in the screenshot, PG7 is present in the graphical view (and it is marked in gray) on the right but it is not available in the left table (which is ordered for pin names in increasing alphabetical order)

I started the project using TouchGFX v4.24.1 with STM32CubeMX to build a basic GUI for my application, then I slightly modified the configuration of pins using the automatically generated .ioc configuration file and the code using STM32Cube FW_F7 v1.17.2.

For completeness of reference I attach also a zip archive with the full project code.

I'm neglecting some detail about the configuration or this can be a problem with TouchGFX?

Cheers.

[CYANG.1 · Accepted solution]

Hi,

Maybe I missed something. But when PG7 is in grey, that means it was not assigned. so PG7 is not shown in the left table. After you assign PG7 as a GPIO and the ball will turn green, then PG7 will be listed in the table.

[Francesco1]

Hi @CYANG.1,

of course you are right; the problem was that PG7 was not initialized at all by the TouchGFX code generator. My limited experience with STM32CubeMX made the rest... 

Sorry for this *** mistake and thank you for your patience.

Cheers.