Arduino for STM32

It works!
Problem was in the library that uses default SPI.
Modify the library by ,
As per you suggestion , open a new class SPI_3 and changed all
commands related.Now is OK ,no default SPI opened and SPI_3
working.
Thanks a lot

#include <Wire.h>
#include <MCP48xx.h>
MCP4822 dac(PC9);

int Pulse = LOW;
int I2C_msg; // Stores command I2C from Raspberry PI

//various IO pins
#define UVled A2 // UV intensity
#define OnBoardLed 13 // arduino led
#define Switch A5 // Enable switch control



//------------ Stepper motors ...

Hi all,
As I wrote in the presentation topic I'm building a film scanner that utilizes 3 stepper motors.
On top I need also to control 2 leds for which I use a DAC (MCP4822) that is controlled via SPI.
Because the stepper shield (Arduino CNC shield) use the same pins of SPI-1 (D11 MOSI D13 SCLK)
I ...

My name is Mauro,I'm a veteran,I'm 75, but still open to learn. I'm now trying to build up a film scanner
to review my 7 years African experience reversed in super8 films. So I need some advices....
Mauro