152 lines
8.0 KiB
Plaintext
152 lines
8.0 KiB
Plaintext
/**
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@page I2C_TwoBoards_RestartComIT I2C Two Boards Communication IT with Restart condition example
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@verbatim
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******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
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* @file I2C/I2C_TwoBoards_RestartComIT/readme.txt
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* @author MCD Application Team
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* @brief Description of the I2C Two Boards IT Communication with Restart condition example.
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******************************************************************************
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* @attention
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*
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* <h2><center>© Copyright (c) 2017 STMicroelectronics.
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* All rights reserved.</center></h2>
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*
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* This software component is licensed by ST under BSD 3-Clause license,
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* the "License"; You may not use this file except in compliance with the
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* License. You may obtain a copy of the License at:
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* opensource.org/licenses/BSD-3-Clause
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*
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******************************************************************************
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@endverbatim
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@par Example Description
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How to handle single I2C data buffer transmission/reception between two boards,
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in interrupt mode and with restart condition.
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_________________________ _________________________
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| ______________| ___VDD____ |______________ |
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| | I2C1 | | | | I2C1| |
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| | | R (4.7K) R | | |
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| | SCL(PB6)|_____|________|_______|(PB6)SCL | |
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| | | | | | |
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| | | | | | |
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| | | | | | |
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| | SDA(PB7)|______________|_______|(PB7)SDA | |
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| | | | | |
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| |______________| |______________| |
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| __ | | __ |
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| |__| | | |__| |
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| USER GND|______________________|GND USER |
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| | | |
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|_STM32F103RB_NUCLEO______| |_STM32F103RB_NUCLEO______|
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This example guides you through the different configuration steps by mean of HAL API
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to ensure I2C Data buffer transmission and reception using Interrupt.
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The communication is done with 2 Boards through I2C.
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At the beginning of the main program the HAL_Init() function is called to reset
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all the peripherals, initialize the Flash interface and the systick.
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Then the SystemClock_Config() function is used to configure the system
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clock (SYSCLK) to run at 64 MHz.
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The I2C peripheral configuration is ensured by the HAL_I2C_Init() function.
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This later is calling the HAL_I2C_MspInit()function which core is implementing
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the configuration of the needed I2C resources according to the used hardware (CLOCK,
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GPIO and NVIC). You may update this function to change I2C configuration.
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The I2C communication is then initiated.
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The project is splitted in two parts the Master Board and the Slave Board
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- Master Board
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The HAL_I2C_Master_Sequential_Transmit_IT() and the HAL_I2C_Master_Sequential_Receive_IT() functions
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allow respectively the transmission and the reception of a predefined data buffer
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in Master mode.
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- Slave Board
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The HAL_I2C_EnableListen_IT(), HAL_I2C_Slave_Sequential_Receive_IT() and the HAL_I2C_Slave_Sequential_Transmit_IT() functions
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allow respectively the "Listen" the I2C bus for address match code event, reception and the transmission of a predefined data buffer
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in Slave mode.
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The user can choose between Master and Slave through "#define MASTER_BOARD"
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in the "main.c" file.
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If the Master board is used, the "#define MASTER_BOARD" must be uncommented.
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If the Slave board is used the "#define MASTER_BOARD" must be commented.
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For this example the aTxBuffer is predefined and the aRxBuffer size is same as aTxBuffer.
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On Master board side:
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- Wait User push-button to be pressed.
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- Request write communication after a Start condition by sending aTxBuffer through HAL_I2C_Master_Sequential_Transmit_IT() to I2C Slave
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- LED2 is turned ON when the transmission process is completed.
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- Then wait User push-button to be pressed.
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- Request read communication after a Repeated Start condition through HAL_I2C_Master_Sequential_Receive_IT() to I2C Slave.
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- Receive data from Slave in aRxBuffer.
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- LED2 is turned OFF when the reception process is completed.
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Finally, aRxBuffer and aTxBuffer are compared through Buffercmp() in order to
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check buffers correctness.
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- LED2 is slowly blinking (1 sec. period) when there is an error in communication process.(communication is stopped if any, using infinite loop)
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On Slave board side:
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- Go Listen mode by calling HAL_I2C_EnableListen_IT().
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- Acknowledge Address match code.
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- Slave receives data into aRxBuffer through HAL_I2C_Slave_Sequential_Receive_IT().
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- LED2 is turned ON when the reception process is completed.
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- Then slave transmits data by sending aTxBuffer through HAL_I2C_Slave_Sequential_Transmit_IT().
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- LED2 is turned OFF when the transmission process is completed.
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Finally, aRxBuffer and aTxBuffer are compared through Buffercmp() in order to
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check buffers correctness.
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LED2 is slowly blinking (1 sec. period) when there is an error in transmission/reception process,
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or buffers compared error. (communication is stopped if any, using infinite loop)
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@note I2Cx instance used and associated resources can be updated in "main.h"
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file depending hardware configuration used.
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@note Care must be taken when using HAL_Delay(), this function provides accurate delay (in milliseconds)
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based on variable incremented in SysTick ISR. This implies that if HAL_Delay() is called from
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a peripheral ISR process, then the SysTick interrupt must have higher priority (numerically lower)
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than the peripheral interrupt. Otherwise the caller ISR process will be blocked.
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To change the SysTick interrupt priority you have to use HAL_NVIC_SetPriority() function.
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@note The application needs to ensure that the SysTick time base is always set to 1 millisecond
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to have correct HAL operation.
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@par Directory contents
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- I2C/I2C_TwoBoards_RestartComIT/Inc/stm32f1xx_hal_conf.h HAL configuration file
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- I2C/I2C_TwoBoards_RestartComIT/Inc/stm32f1xx_it.h I2C interrupt handlers header file
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- I2C/I2C_TwoBoards_RestartComIT/Inc/main.h Header for main.c module
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- I2C/I2C_TwoBoards_RestartComIT/Src/stm32f1xx_it.c I2C interrupt handlers
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- I2C/I2C_TwoBoards_RestartComIT/Src/main.c Main program
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- I2C/I2C_TwoBoards_RestartComIT/Src/system_stm32f1xx.c STM32F1xx system source file
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- I2C/I2C_TwoBoards_RestartComIT/Src/stm32f1xx_hal_msp.c HAL MSP file
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@par Hardware and Software environment
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- This example runs on STM32F103xB devices.
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- This example has been tested with STM32F103RB-Nucleo board and can be
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easily tailored to any other supported device and development board.
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-STM32F103RB-Nucleo Set-up
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- Connect Master board PB6 to Slave Board PB6
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- Connect Master board PB7 to Slave Board PB7
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- Connect Master board GND to Slave Board GND
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- Check that a pull-up resistor is connected on one I2C SDA pin
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- Check that a pull-up resistor is connected on one I2C SCL pin
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- PB6 is connected to pin 3 on CN5 connector ( pin 17 on CN10 connector)
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- PB7 is connected to pin 21 CN7 coonector
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- VDD is connected to pin 8 on CN5 connector ( pin7 on CN10 connector)
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@par How to use it ?
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In order to make the program work, you must do the following :
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- Open your preferred toolchain
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- Rebuild all files and load your image into target memory
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o Uncomment "#define MASTER_BOARD" and load the project in Master Board
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o Comment "#define MASTER_BOARD" and load the project in Slave Board
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- Run the example
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* <h3><center>© COPYRIGHT STMicroelectronics</center></h3>
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*/
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