STM32F4-Discovery I2C with STM32CubeMX

STM32CubeMX

STM32CubeMX is part of STMicroelectronics STMCube™ original initiative to ease developers life by reducing development efforts, time and cost. STM32Cube covers STM32 portfolio.

STM32Cube includes the STM32CubeMX which is a graphical software configuration tool that allows generating C initialization code using graphical wizards.

It also embeds a comprehensive software platform, delivered per series (such as STM32CubeF4 for STM32F4 series). This platform includes the STM32Cube HAL (an STM32 abstraction layer embedded software, ensuring maximized portability across STM32 portfolio), plus a consistent set of middleware components (RTOS, USB, TCP/IP and graphics). All embedded software utilities come with a full set of examples.

STM32CubeMX is an extension of the existing MicroXplorer tool. It is a graphical tool that allows configuring STM32 microcontrollers very easily and generating the corresponding initialization C code through a step-by-step process.

Step one consists in selecting the STMicroelectronics STM32 microcontroller that matches the required set of peripherals.

The user must then configure each required embedded software thanks to a pinout-conflict solver, a clock-tree setting helper, a power-consumption calculator, and an utility performing MCU peripheral configuration (GPIO, USART, ..) and middleware stacks (USB, TCP/IP, ...).

Finally, the user launches the generation of the initialization C code based on the selected configuration. This code is ready to be used within several development environments. The user code is kept at the next code generation.

Source: STMicroelectronics.


I2C

I²C (Inter-Integrated Circuit), pronounced I-squared-C, is a multi-master, multi-slave, single-ended, serial computer bus invented by Philips Semiconductor (now NXP Semiconductors). It is typically used for attaching lower-speed peripheral ICs to processors and microcontrollers. Alternatively I²C is spelled I2C (pronounced I-two-C) or IIC (pronounced I-I-C).

Since October 10, 2006, no licensing fees are required to implement the I²C protocol. However, fees are still required to obtain I²C slave addresses allocated by NXP.

Several competitors, such as Siemens AG (later Infineon Technologies AG, now Intel mobile communications), NEC, Texas Instruments, STMicroelectronics (formerly SGS-Thomson), Motorola (later Freescale, now merged with NXP), Nordic Semiconductor and Intersil, have introduced compatible I²C products to the market since the mid-1990s.

Source: wikipedia.

Project can be downloaded here.

Interface with MCP23017.

main.c code:
/*******************************************************************/

#include "stm32f4xx_hal.h"

I2C_HandleTypeDef hi2c1;

typedef struct{

unsigned char Slave_Adress;
unsigned char Reg_Adress;
unsigned char Data;
}I2C_Struct;

I2C_Struct I2C;

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_I2C1_Init(void);

int main(void){

  HAL_Init();
  SystemClock_Config();

  MX_GPIO_Init();
  MX_I2C1_Init();

I2C.Slave_Adress = 0x40;
I2C.Reg_Adress = 0x00;
I2C.Data = 0;
HAL_I2C_Master_Transmit_IT(&hi2c1, I2C.Slave_Adress, (unsigned char*) &I2C.Reg_Adress, 2);

  while (1);
}

void SystemClock_Config(void){

  RCC_OscInitTypeDef RCC_OscInitStruct;
  RCC_ClkInitTypeDef RCC_ClkInitStruct;

  __PWR_CLK_ENABLE();

  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 8;
  RCC_OscInitStruct.PLL.PLLN = 336;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  HAL_RCC_OscConfig(&RCC_OscInitStruct);

  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK|RCC_CLOCKTYPE_PCLK1
                              |RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;
  HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5);

  HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);

  HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);

  HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);
}

void MX_I2C1_Init(void){

  hi2c1.Instance = I2C1;
  hi2c1.Init.ClockSpeed = 100000;
  hi2c1.Init.DutyCycle = I2C_DUTYCYCLE_2;
  hi2c1.Init.OwnAddress1 = 0;
  hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
  hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLED;
  hi2c1.Init.OwnAddress2 = 0;
  hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLED;
  hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLED;
  HAL_I2C_Init(&hi2c1);

}

void MX_GPIO_Init(void){

  GPIO_InitTypeDef GPIO_InitStruct;

  __GPIOH_CLK_ENABLE();
  __GPIOD_CLK_ENABLE();
  __GPIOB_CLK_ENABLE();

  GPIO_InitStruct.Pin = GPIO_PIN_12|GPIO_PIN_13|GPIO_PIN_14|GPIO_PIN_15;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_LOW;
  HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);

}

void HAL_I2C_MasterTxCpltCallback(I2C_HandleTypeDef *hi2c){

if(hi2c->Instance == I2C1){
I2C.Slave_Adress = 0x40;
I2C.Reg_Adress = 0x12;
I2C.Data = 0xFF;
HAL_I2C_Master_Transmit_IT(&hi2c1, I2C.Slave_Adress, (unsigned char*) &I2C.Reg_Adress, 2);
HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12 | GPIO_PIN_13 | GPIO_PIN_14 |GPIO_PIN_15, GPIO_PIN_SET);
}
}