Communicating Arduino and STM32 with Cubemx on I2C

Hello everyone, in this article we are going to see the communication between Arduino and STM32 over I2C communication protocol. We will use CubeMx and HAL library at STM32 side.

Let's get started.

Firstly let's configure STM side program. In this example we are going to use STM32F429ZI nucleo board. First create a CubeMx project with STM32F429ZI nucleo board and enable I2C hardware.

Below image you can see configuration of I2C:

Then create project. I am suing MDK uVision Keil MDK IDE for development.

In here we are in need of an char array to store incoming data from I2C and communication address value of I2C protocol.

I defined them inside Private Variables section like below:


/* USER CODE BEGIN PV */

#define ARDUINO_PRO_MICRO_I2C_RECEIVE_ADDRESS 0x33<<1
unsigned char ArduinoProMicroI2CData[50];

/* USER CODE END PV */

And in the while loop we need to make requests from Arduino:


while( HAL_I2C_Master_Receive(&hi2c1, ARDUINO_PRO_MICRO_I2C_RECEIVE_ADDRESS , ArduinoProMicroI2CData, 50, 100) != HAL_OK )
{ }
HAL_Delay(1000);

Until here our STM32 program is ready and now Arduinos turn.

Create an Arduino project and write below codes inside:


#include <Wire.h> 

#define DEVICE_ID 0x33 
int counter = 0;

void setup() {
  Wire.begin(DEVICE_ID);  
  Wire.onRequest(requestEvent); 

  Serial.begin(9600);
}

void loop() { }

void requestEvent()
{
  counter++;
  String data = "Counter from Arduino: " + String(counter);
  Serial.println(data);
  Wire.write(data.c_str());  
}

In here:

First we included Wire library
Then we initialized I2C communication protocol
Last created request handler to answer on I2C data requestion.

And lastly most important part of example. Do not forget the connection of Arduino and STM32.

Below list you can see the connections:

Arduino SCL STM32 PB6
Arduino SDA STM32 PB9
Arduino GND STM32 GND
Arduino 5V STM32 5V. (if you are connecting only one board over USB to your PC otherwise this step not required. )

And that is it.

Below image you can see the output of our example:

That is all in this article.

Have a great communication.

Burak Hamdi TUFAN

Share this Post

Send with Whatsapp

Author

Burak Hamdi TUFAN

I am a software developer experienced 15 years and here to share all my programming experiences. I have worked on so many platforms and programming languages especially C, C#, C++ and Java. I am studing PhD at Kocaeli University on Aviation Technologies. I am building softwares and technologies on aviation.

Facebook Twitter Instagram LinkedIn Youtube