RS485测试例程，单片机控制RS485通信

/** ****************************************************************************** * @file stm32f1xx_hal_i2c.c * @author MCD Application Team * @brief I2C HAL module driver. * This file provides firmware functions to manage the following * functionalities of the Inter Integrated Circuit (I2C) peripheral: * + Initialization and de-initialization functions * + IO operation functions * + Peripheral State, Mode and Error functions * @verbatim ============================================================================== ##### How to use this driver ##### ============================================================================== [..] The I2C HAL driver can be used as follows: (#) Declare a I2C_HandleTypeDef handle structure, for example: I2C_HandleTypeDef hi2c; (#)Initialize the I2C low level resources by implementing the @ref HAL_I2C_MspInit() API: (##) Enable the I2Cx interface clock (##) I2C pins configuration (+++) Enable the clock for the I2C GPIOs (+++) Configure I2C pins as alternate function open-drain (##) NVIC configuration if you need to use interrupt process (+++) Configure the I2Cx interrupt priority (+++) Enable the NVIC I2C IRQ Channel (##) DMA Configuration if you need to use DMA process (+++) Declare a DMA_HandleTypeDef handle structure for the transmit or receive channel (+++) Enable the DMAx interface clock using (+++) Configure the DMA handle parameters (+++) Configure the DMA Tx or Rx channel (+++) Associate the initialized DMA handle to the hi2c DMA Tx or Rx handle (+++) Configure the priority and enable the NVIC for the transfer complete interrupt on the DMA Tx or Rx channel (#) Configure the Communication Speed, Duty cycle, Addressing mode, Own Address1, Dual Addressing mode, Own Address2, General call and Nostretch mode in the hi2c Init structure. (#) Initialize the I2C registers by calling the @ref HAL_I2C_Init(), configures also the low level Hardware (GPIO, CLOCK, NVIC...etc) by calling the customized @ref HAL_I2C_MspInit() API. (#) To check if target device is ready for communication, use the function @ref HAL_I2C_IsDeviceReady() (#) For I2C IO and IO MEM operations, three operation modes are available within this driver : *** Polling mode IO operation *** ================================= [..] (+) Transmit in master mode an amount of data in blocking mode using @ref HAL_I2C_Master_Transmit() (+) Receive in master mode an amount of data in blocking mode using @ref HAL_I2C_Master_Receive() (+) Transmit in slave mode an amount of data in blocking mode using @ref HAL_I2C_Slave_Transmit() (+) Receive in slave mode an amount of data in blocking mode using @ref HAL_I2C_Slave_Receive() *** Polling mode IO MEM operation *** ===================================== [..] (+) Write an amount of data in blocking mode to a specific memory address using @ref HAL_I2C_Mem_Write() (+) Read an amount of data in blocking mode from a specific memory address using @ref HAL_I2C_Mem_Read() *** Interrupt mode IO operation *** =================================== [..] (+) Transmit in master mode an amount of data in non-blocking mode using @ref HAL_I2C_Master_Transmit_IT() (+) At transmission end of transfer, @ref HAL_I2C_MasterTxCpltCallback() is executed and user can add his own code by customization of function pointer @ref HAL_I2C_MasterTxCpltCallback() (+) Receive in master mode an amount of data in non-blocking mode using @ref HAL_I2C_Master_Receive_IT() (+) At reception end of transfer, @ref HAL_I2C_MasterRxCpltCallback() is executed and user can add his own code by customization of function pointer @ref HAL_I2C_MasterRxCpltCallback() (+) Transmit in slave mode an amount of data in non-blocking mode using @ref HAL_I2C_Slave_Transmit_IT() (+) At transmission end of transfer, @ref HAL_I2C_SlaveTxCpltCallback() is executed and user can add his own code by customization of function pointer @ref HAL_I2C_SlaveTxCpltCallback() (+) Receive in slave mode an amount of data in non-blocking mode using @ref HAL_I2C_Slave_Receive_IT() (+) At reception end of transfer, @ref HAL_I2C_SlaveRxCpltCallback() is executed and user can add his own code by customization of function pointer @ref HAL_I2C_SlaveRxCpltCallback() (+) In case of transfer Error, @ref HAL_I2C_ErrorCallback() function is executed and user can add his own code by customization of function pointer @ref HAL_I2C_ErrorCallback() (+) Abort a master I2C process communication with Interrupt using @ref HAL_I2C_Master_Abort_IT() (+) End of abort process, @ref HAL_I2C_AbortCpltCallback() is executed and user can add his own code by customization of function pointer @ref HAL_I2C_AbortCpltCallback() *** Interrupt mode or DMA mode IO sequential operation *** ========================================================== [..] (@) These interfaces allow to manage a sequential transfer with a repeated start condition when a direction change during transfer [..] (+) A specific option field manage the different steps of a sequential transfer (+) Option field values are defined through @ref I2C_XferOptions_definition and are listed below: (++) I2C_FIRST_AND_LAST_FRAME: No sequential usage, functionnal is same as associated interfaces in no sequential mode (++) I2C_FIRST_FRAME: Sequential usage, this option allow to manage a sequence with start condition, address and data to transfer without a final stop condition (++) I2C_FIRST_AND_NEXT_FRAME: Sequential usage (Master only), this option allow to manage a sequence with start condition, address and data to transfer without a final stop condition, an then permit a call the same master sequential interface several times (like @ref HAL_I2C_Master_Seq_Transmit_IT() then @ref HAL_I2C_Master_Seq_Transmit_IT() or @ref HAL_I2C_Master_Seq_Transmit_DMA() then @ref HAL_I2C_Master_Seq_Transmit_DMA()) (++) I2C_NEXT_FRAME: Sequential usage, this option allow to manage a sequence with a restart condition, address and with new data to transfer if the direction change or manage only the new data to transfer if no direction change and without a final stop condition in both cases (++) I2C_LAST_FRAME: Sequential usage, this option allow to manage a sequance with a restart condition, address and with new data to transfer if the direction change or manage only the new data to transfer if no direction change and with a final stop condition in both cases (++) I2C_LAST_FRAME_NO_STOP: Sequential usage (Master only), this option allow to manage a restart condition after several call of the same master sequential interface several times (link with option I2C_FIRST_AND_NEXT_FRAME). Usage can, transfer several bytes one by one using HAL_I2C_Master_Seq_Transmit_IT(option I2C_FIRST_AND_NEXT_FRAME then I2C_NEXT_FRAME) or HAL_I2C_Master_Seq_Receive_IT(option I2C_FIRST_AND_NEXT_FRAME then I2C_NEXT_FRAME) or HAL_I2C_Master_Seq_Transmit_DMA(option I2C_FIRST_AND_NEXT_FRAME then I2C_NEXT_FRAME) or HAL_I2C_Master_Seq_Receive_