Hi Ryan, I am confused by the interrupt IRS enabling in the start up file.. Here is the I2C driver code I used and it is working for me.(From " BOOSTXL-EDUMKII _LightSensor_ MSP432P401R " example) 2 questions : 1) The i2cwrite part did not use any interrupt, Is this implementation even correct? Because, There is another i2c driver code from another example.( i2c_driver.c ) It has a very different implementation using interrupt IRQ. 2) The reading part used the interrupt(Polling) ,but The start-up file did not define IRS for EUSCIB1_IRQ Handler at all. Why is this working? if i continue use this driver, Will i expect to have problems? Thanks, Eddy /* --COPYRIGHT--,BSD * Copyright (c) 2015, Texas Instruments Incorporated * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * * Neither the name of Texas Instruments Incorporated nor the names of * its contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * --/COPYRIGHT--*/ //**************************************************************************** // // HAL_I2C.c - Hardware abstraction layer for I2C with MSP432P401R // //**************************************************************************** #include #include /* I2C Master Configuration Parameter */ const eUSCI_I2C_MasterConfig i2cConfig = { EUSCI_B_I2C_CLOCKSOURCE_SMCLK, // SMCLK Clock Source 12000000, // SMCLK = 24MHz EUSCI_B_I2C_SET_DATA_RATE_400KBPS, // Desired I2C Clock of 100khz 0, // No byte counter threshold EUSCI_B_I2C_NO_AUTO_STOP // No Autostop }; void Init_I2C_GPIO() { /* Select I2C function for I2C_SCL(P6.5) & I2C_SDA(P6.4) */ GPIO_setAsPeripheralModuleFunctionOutputPin( GPIO_PORT_P6, GPIO_PIN5, GPIO_PRIMARY_MODULE_FUNCTION); GPIO_setAsPeripheralModuleFunctionOutputPin( GPIO_PORT_P6, GPIO_PIN4, GPIO_PRIMARY_MODULE_FUNCTION); } /***************************************************************************//** * @brief Configures I2C * @param none * @return none ******************************************************************************/ void I2C_init(void) { /* Initialize USCI_B0 and I2C Master to communicate with slave devices*/ I2C_initMaster(EUSCI_B1_BASE, &i2cConfig); /* Disable I2C module to make changes */ I2C_disableModule(EUSCI_B1_BASE); /* Enable I2C Module to start operations */ I2C_enableModule(EUSCI_B1_BASE); return; } /***************************************************************************//** * @brief Reads data from the sensor * @param writeByte Address of register to read from * @return Register contents ******************************************************************************/ int I2C_read16(unsigned char writeByte) { volatile int val = 0; volatile int valScratch = 0; /* Set master to transmit mode PL */ I2C_setMode(EUSCI_B1_BASE, EUSCI_B_I2C_TRANSMIT_MODE); /* Clear any existing interrupt flag PL */ I2C_clearInterruptFlag(EUSCI_B1_BASE, EUSCI_B_I2C_TRANSMIT_INTERRUPT0); /* Wait until ready to write PL */ while (I2C_isBusBusy(EUSCI_B1_BASE)); /* Initiate start and send first character */ I2C_masterSendMultiByteStart(EUSCI_B1_BASE, writeByte); /* Wait for TX to finish */ while(!(I2C_getInterruptStatus(EUSCI_B1_BASE, EUSCI_B_I2C_TRANSMIT_INTERRUPT0))); /* Initiate stop only */ I2C_masterSendMultiByteStop(EUSCI_B1_BASE); /* Wait for Stop to finish */ while(!I2C_getInterruptStatus(EUSCI_B1_BASE, EUSCI_B_I2C_STOP_INTERRUPT)); /* * Generate Start condition and set it to receive mode. * This sends out the slave address and continues to read * until you issue a STOP */ I2C_masterReceiveStart(EUSCI_B1_BASE); /* Wait for RX buffer to fill */ while(!(I2C_getInterruptStatus(EUSCI_B1_BASE, EUSCI_B_I2C_RECEIVE_INTERRUPT0))); /* Read from I2C RX register */ val = I2C_masterReceiveMultiByteNext(EUSCI_B1_BASE); /* Receive second byte then send STOP condition */ valScratch = I2C_masterReceiveMultiByteFinish(EUSCI_B1_BASE); /* Shift val to top MSB */ val = (val >8)); I2C_masterSendMultiByteFinish(EUSCI_B1_BASE, (unsigned char)(writeByte&0xFF)); } void I2C_write8 (unsigned int slaveAdr,unsigned char pointer, unsigned int writeByte) { I2C_setslave(slaveAdr); /* Set master to transmit mode PL */ I2C_setMode(EUSCI_B1_BASE, EUSCI_B_I2C_TRANSMIT_MODE); /* Clear any existing interrupt flag PL */ I2C_clearInterruptFlag(EUSCI_B1_BASE, EUSCI_B_I2C_TRANSMIT_INTERRUPT0); /* Wait until ready to write PL */ while (I2C_isBusBusy(EUSCI_B1_BASE)); /* Initiate start and send first character */ I2C_masterSendMultiByteStart(EUSCI_B1_BASE, pointer); /* Send the MSB to SENSOR */ I2C_masterSendMultiByteFinish(EUSCI_B1_BASE, (unsigned char)(writeByte)); } int I2C_read8(unsigned int slaveAdr,unsigned char writeByte) { volatile int val = 0; volatile int valScratch = 0; /* Set master to transmit mode PL */ I2C_setMode(EUSCI_B1_BASE, EUSCI_B_I2C_TRANSMIT_MODE); /* Clear any existing interrupt flag PL */ I2C_clearInterruptFlag(EUSCI_B1_BASE, EUSCI_B_I2C_TRANSMIT_INTERRUPT0); /* Wait until ready to write PL */ while (I2C_isBusBusy(EUSCI_B1_BASE)); /* Initiate start and send first character */ I2C_masterSendMultiByteStart(EUSCI_B1_BASE, writeByte); /* Wait for TX to finish */ while(!(I2C_getInterruptStatus(EUSCI_B1_BASE, EUSCI_B_I2C_TRANSMIT_INTERRUPT0))); /* Initiate stop only */ I2C_masterSendMultiByteStop(EUSCI_B1_BASE); /* Wait for Stop to finish */ while(!I2C_getInterruptStatus(EUSCI_B1_BASE, EUSCI_B_I2C_STOP_INTERRUPT)); /* * Generate Start condition and set it to receive mode. * This sends out the slave address and continues to read * until you issue a STOP */ I2C_masterReceiveStart(EUSCI_B1_BASE); /* Wait for RX buffer to fill */ while(!(I2C_getInterruptStatus(EUSCI_B1_BASE, EUSCI_B_I2C_RECEIVE_INTERRUPT0))); /* Read from I2C RX register */ val = I2C_masterReceiveMultiByteNext(EUSCI_B1_BASE); /* Receive second byte then send STOP condition */ valScratch = I2C_masterReceiveMultiByteFinish(EUSCI_B1_BASE); return val; } void I2C_setslave(unsigned int slaveAdr) { /* Specify slave address for I2C */ I2C_setSlaveAddress(EUSCI_B1_BASE, slaveAdr); /* Enable and clear the interrupt flag */ I2C_clearInterruptFlag(EUSCI_B1_BASE, EUSCI_B_I2C_TRANSMIT_INTERRUPT0 + EUSCI_B_I2C_RECEIVE_INTERRUPT0); return; }
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