Amazing Open Source Raspberry Pi Pico 2 Synth, Cutting Edge Power over Skin Research, and much more!

0:00:00 / -

Watch now on YouTube Watch now

Easy Programming STM32F407 Discovery Board with mbed

Made by electrouser805

About the project

A quick start guide to program STM32F407 Discovery Board with mbed online IDE.

Project info

Difficulty: Easy

Platforms: Arm Mbed

Estimated time: 1 hour

License: Apache License 2.0 (Apache-2.0)

Items used in this project

Hardware components

	Ultrasonic Sensor Hc-sr04	x 1
	Avr-iot Wg Evaluation Board	x 1

Software apps and online services

Arm Mbed Mbed Studio

Hand tools and fabrication machines

Arm Mbed mbed

x 1

Story

Why?

STM32F407 Discovery board does not directly support MBED online IDE. But the mcu on this board is also used in another official MBED board ( Seeed Studio Arch Max v1.1 ) . So, it is possible to program Discovery board by treating it as an Arch Max board.

It's an easy way for rapid prototyping with online IDE of MBED. No need to install Keil/IAR/AC6 on PC and go through painful setup.
Common things like ADC/PWM/DAC/GPIO/UART/SPI/I2C can be used with minimum configuration.
On board accelerometer is also tested.

Attached code below demonstrates all these functionalities.

mbed.org

Step 2: Select Platform Seeed Arch Max

Selecting platform

Step 3: Edit, Compile and Download Code

Following code demonstrated GPIO, ADC, Serial, PWM and On board Accelerometer capabilities

Library:

#include "mbed.h"
#include "LIS3DSH.h"

GPIO and Pwm Initialization:

DigitalOut rLED(PD_14);   // on board red LED, DO
DigitalOut bLED(PD_15);   // on board blue LED. DO
DigitalOut gLED(PD_12);   // on board green LED, DO
DigitalOut oLED(PD_13);   // on board orange LED, DO
PwmOut GLED(PA_9);        // on board green LED, 
PWMDigitalIn  pbSW(PA_0);    // on board blue PUSH Switch, active high DI

Serial and ADC:

Serial serial(PA_2,PA_3); // serial com tx, rx UART
AnalogIn   adcPB0(PB_0);  // PB0 as 12 bit ADC

Serial baud and print:

  // set serial baud and print welcome msg //    
serial.baud(19200);    
serial.printf("Welcome to STM32F407 Development with mbedOS nr");

PWM Frequency and Duty Cycle:

GLED.period(1.0f/freq);  // set pwm period
GLED.write(duty/100.0f); // set pwm duty cycle

LED Blink:

 rLED = 1;
 gLED = 1;
 wait(delay);
 rLED = 0;  
 gLED = 0;   
 wait(delay);

ADC Read:

  // adc value read // 
  adcval = 4095*adcPB0.read_u16()/65535; // 12 bit value

Pins shared with on board hardware

"Not-Marked" pins are not recommended to use, these might interfere with on board hardwares

Update 1: DAC works on PA4 and PA5

Just tested 12 bit DAC on A4 and A5 pins. It works. But, Accelerometer and Audio might not be used along with DAC for other application (same pin).

DAC Setup:

// Before main
AnalogOut dac1(PA_5); 
AnalogOut dac2(PA_4);

Output Analog Voltage:

// set up 1 volt on dac 1
dac1 = 0.333f; // vdd* 0.333 = 3.0*0.333 =  1.0 volt
// set up 1.5 volt on dac 2
dac2 = 0.5f; // vdd*0.5 = 1.5 volt

Update 2: 20x4 LCD support

Tested lcd display with mbed, working great ! 5 volts display runs with 3.3 v logic without issues. Code link will be added after final testing.

Caveats

Not all functions will work according to above pin map. For example Pwm on PD13 will not work on mbed. Because, mbed compiler treats the code according to Arch Max boards pin mapping.

For, pin specific function that will work for sure, see the pin map attached below.

Based on Arch Max Pin Mapping (download schematic below for better image)

External Resources

Farrukh's Tutorial

Arch Max Pin Map

STM32F407 Technical Docs

Schematics, diagrams and documents

pin mapping

Code

Untitled file

mbed os 2, dont updateLink: https://os.mbed.com/users/suntopbd/code/STM32F407/

// libraries //
#include "mbed.h"
#include "LIS3DSH.h"
///////////////////////////////////////////////////////////////

// **see DocID022256 rev6 (google it) page 27-31 schematic** //
// Note: following pins are connected to onboard hardware //
///////////////////////////////////////////////////////////////
// i/o initialization //
DigitalOut rLED(PD_14);   // on board red LED, DO
DigitalOut bLED(PD_15);   // on board blue LED. DO
DigitalOut gLED(PD_12);   // on board green LED, DO
DigitalOut oLED(PD_13);   // on board orange LED, DO
PwmOut GLED(PA_9);        // on board green LED, PWM
DigitalIn  pbSW(PA_0);    // on board blue PUSH Switch, active high DI

/////////////////////////////////////////////////////////////////
// on board accerometer  mosi, miso, clk , cs  pins //
LIS3DSH acc(PA_7, PA_6, PA_5, PE_3);
// INT1 PE_0
// INT2 PE_1
/////////////////////////////////////////////////////////////////
// on board digital mic MP45DT02//
DigitalOut mic_clk(PB_10);
DigitalIn mic_data(PC_3);
// on board audio dac CS43L22 //
// Audio_SDA PB_9
// Audio_SCL PB_6
// Audio_RST PD_4
// DAC_Out PA_4
// PDM_Out PC_4
// ISS_MCK PC_7
// ISS_CLK PC_10
// ISS_SDI  PC_12
// ISS_WS PA_4
//////////////////////////////////////////////////////////////////
Serial serial(PA_2,PA_3); // serial com tx, rx UART
AnalogIn   adcPB0(PB_0);  // PB0 as 12 bit ADC


// variables declearation //
double delay = 0.2;     // delay variable for wait 
double freq = 1000.0f;  // pwm frequency variable upto 84 Mhz
double duty = 50.0f;    // duty cycle of pwm variable 0.0 - 99.9
uint16_t adcval=0;      // adc value capture variable
int16_t X, Y, Z;        // signed integer variables for X,Y,Z values
float roll, pitch;      // float variables for angle
// main code //
int main() 
{
     //////////////////////////////////////////////////////////////
      // set serial baud and print welcome msg //
    serial.baud(19200);
    serial.printf("Welcome to STM32F407 Development with mbedOS \n\r");
                  
             
       GLED.period(1.0f/freq);  // set pwm period      
       GLED.write(duty/100.0f); // set pwm duty cycle
    while(1) 
    { 
        //////////////////////////////////////////////////////////// 
         // on board RGBO LED blink //
                rLED = 1;
                gLED = 1;
                wait(delay);
                rLED = 0;
                gLED = 0;
                wait(delay);
                
                bLED = 1;
                oLED = 1;
                wait(delay);
                bLED = 0; 
                oLED = 0;
                wait(delay);
          //////////////////////////////////////////////////////////////////      
          // on board user push switch test // 
                if (pbSW==1) 
                 {
                      // adc value read //         
                   adcval = 4095*adcPB0.read_u16()/65535; // 12 bit value
                      // serial message //
          ///////////////////////////////////////////////////////////////////
                      
                   serial.printf("Button Pressed\n\r");
                   serial.printf("ADC on PB0: %d\n\r", adcval);
                   delay=delay+.05;
                   wait(.2);
          //////////////////////////////////////////////////////////////////         
                      // PWM fading green LED 2 //
                   for(double i=0.0; i<1.0;i=i+0.01)
                    {
                      GLED.write(i); // duty cycle changing
                      wait(.01);
                    }
              
                   for(double i=0.0; i<1.0;i=i+0.01)
                    {
                      GLED.write(1.0-i); // duty cycle changing
                      wait(.01);
                    }
                   }// end of if //   
            /////////////////////////////////////////////////////////////////
            // on board accerometer //  
            if(acc.Detect() != 1)
             {
              serial.printf("LIS3DSH acceromoter not detected!\n\r");
             }
             else
             {
              serial.printf("LIS3DSH acceromoter detected! , Reading now\n\r");
              acc.ReadData(&X, &Y, &Z);           // reads X, Y, Z values
              acc.ReadAngles(&roll, &pitch);      // reads roll and pitch angles
              serial.printf("X: %d  Y: %d  Z: %d\n\r", X, Y, Z);
              serial.printf("Roll: %f   Pitch: %f\n\r", roll, pitch);
              // divide raw value by 1750 to get acceleration in m/s^2 //
             }     
             ///////////////////////////////////////////////////////////////
  
     
                 
    }// end of while //
}// end of main

Shop

Project Hub

Video

Blog

Shop home

3D printing

Single Board Computers

Development kits

Sensors

Internet of things

Robotics

Accessories

Product of the Week

Electromaker Educator

The Electromaker Show

The Electromaker Podcast

Easy Programming STM32F407 Discovery Board with mbed

About the project

Project info

Items used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Why?

Step 2: Select Platform Seeed Arch Max

Step 3: Edit, Compile and Download Code

Pins shared with on board hardware

Update 1: DAC works on PA4 and PA5

Update 2: 20x4 LCD support

Caveats

External Resources

Schematics, diagrams and documents

pin mapping

Code

Untitled file

Credits

electrouser805

Leave your feedback...

Shop

Project Hub

Video

Blog

Shop home

3D printing

Single Board Computers

Development kits

Sensors

Internet of things

Robotics

Accessories

Product of the Week

Electromaker Educator

The Electromaker Show

The Electromaker Podcast

Easy Programming STM32F407 Discovery Board with mbed

About the project

Project info

Items used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Why?

Step 1: Go to mbed.org and login/signup

Step 2: Select Platform Seeed Arch Max

Step 3: Edit, Compile and Download Code

Pins shared with on board hardware

Update 1: DAC works on PA4 and PA5

Update 2: 20x4 LCD support

Caveats

External Resources

Schematics, diagrams and documents

pin mapping

Code

Untitled file

Credits

electrouser805

Leave your feedback...

Related products