开的是主从的回环模式
//*****************************************************************************//// master_slave_loopback.c - Example demonstrating a simple I2C message// transmission and reception.//// Copyright (c) 2010-2014 Texas Instruments Incorporated. All rights reserved.// Software License Agreement// // 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.// // This is part of revision 2.1.0.12573 of the Tiva Firmware Development Package.////*****************************************************************************#include
#include #include "inc/hw_i2c.h"#include "inc/hw_memmap.h"#include "inc/hw_types.h"#include "driverlib/gpio.h"#include "driverlib/i2c.h"#include "driverlib/pin_map.h"#include "driverlib/sysctl.h"#include "driverlib/uart.h"#include "utils/uartstdio.h"//*****************************************************************************////! addtogroup i2c_examples_list//! I2C Master Loopback (i2c_master_slave_loopback)
//!//! This example shows how to configure the I2C0 module for loopback mode.//! This includes setting up the master and slave module. Loopback mode//! internally connects the master and slave data and clock lines together.//! The address of the slave module is set in order to read data from the//! master. Then the data is checked to make sure the received data matches//! the data that was transmitted. This example uses a polling method for//! sending and receiving data.//!//! This example uses the following peripherals and I/O signals. You must//! review these and change as needed for your own board://! - I2C0 peripheral//! - GPIO Port B peripheral (for I2C0 pins)//! - I2C0SCL - PB2//! - I2C0SDA - PB3//!//! The following UART signals are configured only for displaying console//! messages for this example. These are not required for operation of I2C.//! - UART0 peripheral//! - GPIO Port A peripheral (for UART0 pins)//! - UART0RX - PA0//! - UART0TX - PA1//!//! This example uses the following interrupt handlers. To use this example//! in your own application you must add these interrupt handlers to your//! vector table.//! - None.////*****************************************************************************//*****************************************************************************//// Number of I2C data packets to send.////*****************************************************************************#define NUM_I2C_DATA 3//*****************************************************************************//// Set the address for slave module. This is a 7-bit address sent in the// following format:// [A6:A5:A4:A3:A2:A1:A0:RS]//// A zero in the "RS" position of the first byte means that the master// transmits (sends) data to the selected slave, and a one in this position// means that the master receives data from the slave.////*****************************************************************************#define SLAVE_ADDRESS 0x3C//*****************************************************************************//// This function sets up UART0 to be used for a console to display information// as the example is running.////*****************************************************************************voidInitConsole(void)[ // // Enable GPIO port A which is used for UART0 pins. // TODO: change this to whichever GPIO port you are using. // SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA); // // Configure the pin muxing for UART0 functions on port A0 and A1. // This step is not necessary if your part does not support pin muxing. // TODO: change this to select the port/pin you are using. // GPIOPinConfigure(GPIO_PA0_U0RX); GPIOPinConfigure(GPIO_PA1_U0TX); // // Enable UART0 so that we can configure the clock. // SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0); // // Use the internal 16MHz oscillator as the UART clock source. // UARTClockSourceSet(UART0_BASE, UART_CLOCK_PIOSC); // // Select the alternate (UART) function for these pins. // TODO: change this to select the port/pin you are using. // GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1); // // Initialize the UART for console I/O. // UARTStdioConfig(0, 115200, 16000000);]//*****************************************************************************//// Configure the I2C0 master and slave and connect them using loopback mode.////*****************************************************************************intmain(void)[ uint32_t pui32DataTx[NUM_I2C_DATA]; uint32_t pui32DataRx[NUM_I2C_DATA]; uint32_t ui32Index; // // Set the clocking to run directly from the external crystal/oscillator. // TODO: The SYSCTL_XTAL_ value must be changed to match the value of the // crystal on your board. // SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN | SYSCTL_XTAL_16MHZ); // // The I2C0 peripheral must be enabled before use. // SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C0); // // For this example I2C0 is used with PortB[3:2]. The actual port and // pins used may be different on your part, consult the data sheet for // more information. GPIO port B needs to be enabled so these pins can // be used. // TODO: change this to whichever GPIO port you are using. // SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB); // // Configure the pin muxing for I2C0 functions on port B2 and B3. // This step is not necessary if your part does not support pin muxing. // TODO: change this to select the port/pin you are using. // GPIOPinConfigure(GPIO_PB2_I2C0SCL); GPIOPinConfigure(GPIO_PB3_I2C0SDA); // // Select the I2C function for these pins. This function will also // configure the GPIO pins pins for I2C operation, setting them to // open-drain operation with weak pull-ups. Consult the data sheet // to see which functions are allocated per pin. // TODO: change this to select the port/pin you are using. // GPIOPinTypeI2CSCL(GPIO_PORTB_BASE, GPIO_PIN_2); GPIOPinTypeI2C(GPIO_PORTB_BASE, GPIO_PIN_3); // // Enable loopback mode. Loopback mode is a built in feature that is // useful for debugging I2C operations. It internally connects the I2C // master and slave terminals, which effectively let's you send data as // a master and receive data as a slave. // NOTE: For external I2C operation you will need to use external pullups // that are stronger than the internal pullups. Refer to the datasheet for // more information. // HWREG(I2C0_BASE + I2C_O_MCR) |= 0x01; // // Enable and initialize the I2C0 master module. Use the system clock for // the I2C0 module. The last parameter sets the I2C data transfer rate. // If false the data rate is set to 100kbps and if true the data rate will // be set to 400kbps. For this example we will use a data rate of 100kbps. // I2CMasterInitExpClk(I2C0_BASE, SysCtlClockGet(), false); // // Enable the I2C0 slave module. This module is enabled only for testing // purposes. It does not need to be enabled for proper operation of the // I2Cx master module. // I2CSlaveEnable(I2C0_BASE); // // Set the slave address to SLAVE_ADDRESS. In loopback mode, it's an // arbitrary 7-bit number (set in a macro above) that is sent to the // I2CMasterSlaveAddrSet function. // I2CSlaveInit(I2C0_BASE, SLAVE_ADDRESS); // // Tell the master module what address it will place on the bus when // communicating with the slave. Set the address to SLAVE_ADDRESS // (as set in the slave module). The receive parameter is set to false // which indicates the I2C Master is initiating a writes to the slave. If // true, that would indicate that the I2C Master is initiating reads from // the slave. // I2CMasterSlaveAddrSet(I2C0_BASE, SLAVE_ADDRESS, false); // // Set up the serial console to use for displaying messages. This is // just for this example program and is not needed for I2C operation. // InitConsole(); // // Display the example setup on the console. // UARTprintf("I2C Loopback Example ->"); UARTprintf("n Module = I2C0"); UARTprintf("n Mode = Single Send/Receive"); UARTprintf("n Rate = 100kbpsnn"); // // Initalize the data to send. // pui32DataTx[0] = 'I'; pui32DataTx[1] = '2'; pui32DataTx[2] = 'C'; // // Initalize the receive buffer. // for(ui32Index = 0; ui32Index < NUM_I2C_DATA; ui32Index++) [ pui32DataRx[ui32Index] = 0; ] // // Indicate the direction of the data. // UARTprintf("Tranferring from: Master -> Slaven"); // // Send 3 peices of I2C data from the master to the slave. // for(ui32Index = 0; ui32Index < NUM_I2C_DATA; ui32Index++) [ // // Display the data that the I2C0 master is transferring. // UARTprintf(" Sending: '%c' . . . ", pui32DataTx[ui32Index]); // // Place the data to be sent in the data register // I2CMasterDataPut(I2C0_BASE, pui32DataTx[ui32Index]); // // Initiate send of data from the master. Since the loopback // mode is enabled, the master and slave units are connected // allowing us to receive the same data that we sent out. // I2CMasterControl(I2C0_BASE, I2C_MASTER_CMD_SINGLE_SEND); // // Wait until the slave has received and acknowledged the data. // while(!(I2CSlaveStatus(I2C0_BASE) & I2C_SLAVE_ACT_RREQ)) [ ] // // Read the data from the slave. // pui32DataRx[ui32Index] = I2CSlaveDataGet(I2C0_BASE); // // Wait until master module is done transferring. // while(I2CMasterBusy(I2C0_BASE)) [ ] // // Display the data that the slave has received. // UARTprintf("Received: '%c'n", pui32DataRx[ui32Index]); ] // // Reset receive buffer. // for(ui32Index = 0; ui32Index < NUM_I2C_DATA; ui32Index++) [ pui32DataRx[ui32Index] = 0; ] // // Indicate the direction of the data. // UARTprintf("nnTranferring from: Slave -> Mastern"); // // Modifiy the data direction to true, so that seeing the address will // indicate that the I2C Master is initiating a read from the slave. // I2CMasterSlaveAddrSet(I2C0_BASE, SLAVE_ADDRESS, true); // // Do a dummy receive to make sure you don't get junk on the first receive. // I2CMasterControl(I2C0_BASE, I2C_MASTER_CMD_SINGLE_RECEIVE); // // Dummy acknowledge and wait for the receive request from the master. // This is done to clear any flags that should not be set. // while(!(I2CSlaveStatus(I2C0_BASE) & I2C_SLAVE_ACT_TREQ)) [ ] for(ui32Index = 0; ui32Index < NUM_I2C_DATA; ui32Index++) [ // // Display the data that I2C0 slave module is transferring. // UARTprintf(" Sending: '%c' . . . ", pui32DataTx[ui32Index]); // // Place the data to be sent in the data register // I2CSlaveDataPut(I2C0_BASE, pui32DataTx[ui32Index]); // // Tell the master to read data. // I2CMasterControl(I2C0_BASE, I2C_MASTER_CMD_SINGLE_RECEIVE); // // Wait until the slave is done sending data. // while(!(I2CSlaveStatus(I2C0_BASE) & I2C_SLAVE_ACT_TREQ)) [ ] // // Read the data from the master. // pui32DataRx[ui32Index] = I2CMasterDataGet(I2C0_BASE); // // Display the data that the slave has received. // UARTprintf("Received: '%c'n", pui32DataRx[ui32Index]); ] // // Tell the user that the test is done. // UARTprintf("nDone.nn"); // // Return no errors // return(0);]
开的是主从的回环模式
//*****************************************************************************//// master_slave_loopback.c - Example demonstrating a simple I2C message// transmission and reception.//// Copyright (c) 2010-2014 Texas Instruments Incorporated. All rights reserved.// Software License Agreement// // 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.// // This is part of revision 2.1.0.12573 of the Tiva Firmware Development Package.////*****************************************************************************#include
#include #include "inc/hw_i2c.h"#include "inc/hw_memmap.h"#include "inc/hw_types.h"#include "driverlib/gpio.h"#include "driverlib/i2c.h"#include "driverlib/pin_map.h"#include "driverlib/sysctl.h"#include "driverlib/uart.h"#include "utils/uartstdio.h"//*****************************************************************************////! addtogroup i2c_examples_list//! I2C Master Loopback (i2c_master_slave_loopback)
//!//! This example shows how to configure the I2C0 module for loopback mode.//! This includes setting up the master and slave module. Loopback mode//! internally connects the master and slave data and clock lines together.//! The address of the slave module is set in order to read data from the//! master. Then the data is checked to make sure the received data matches//! the data that was transmitted. This example uses a polling method for//! sending and receiving data.//!//! This example uses the following peripherals and I/O signals. You must//! review these and change as needed for your own board://! - I2C0 peripheral//! - GPIO Port B peripheral (for I2C0 pins)//! - I2C0SCL - PB2//! - I2C0SDA - PB3//!//! The following UART signals are configured only for displaying console//! messages for this example. These are not required for operation of I2C.//! - UART0 peripheral//! - GPIO Port A peripheral (for UART0 pins)//! - UART0RX - PA0//! - UART0TX - PA1//!//! This example uses the following interrupt handlers. To use this example//! in your own application you must add these interrupt handlers to your//! vector table.//! - None.////*****************************************************************************//*****************************************************************************//// Number of I2C data packets to send.////*****************************************************************************#define NUM_I2C_DATA 3//*****************************************************************************//// Set the address for slave module. This is a 7-bit address sent in the// following format:// [A6:A5:A4:A3:A2:A1:A0:RS]//// A zero in the "RS" position of the first byte means that the master// transmits (sends) data to the selected slave, and a one in this position// means that the master receives data from the slave.////*****************************************************************************#define SLAVE_ADDRESS 0x3C//*****************************************************************************//// This function sets up UART0 to be used for a console to display information// as the example is running.////*****************************************************************************voidInitConsole(void)[ // // Enable GPIO port A which is used for UART0 pins. // TODO: change this to whichever GPIO port you are using. // SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA); // // Configure the pin muxing for UART0 functions on port A0 and A1. // This step is not necessary if your part does not support pin muxing. // TODO: change this to select the port/pin you are using. // GPIOPinConfigure(GPIO_PA0_U0RX); GPIOPinConfigure(GPIO_PA1_U0TX); // // Enable UART0 so that we can configure the clock. // SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0); // // Use the internal 16MHz oscillator as the UART clock source. // UARTClockSourceSet(UART0_BASE, UART_CLOCK_PIOSC); // // Select the alternate (UART) function for these pins. // TODO: change this to select the port/pin you are using. // GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1); // // Initialize the UART for console I/O. // UARTStdioConfig(0, 115200, 16000000);]//*****************************************************************************//// Configure the I2C0 master and slave and connect them using loopback mode.////*****************************************************************************intmain(void)[ uint32_t pui32DataTx[NUM_I2C_DATA]; uint32_t pui32DataRx[NUM_I2C_DATA]; uint32_t ui32Index; // // Set the clocking to run directly from the external crystal/oscillator. // TODO: The SYSCTL_XTAL_ value must be changed to match the value of the // crystal on your board. // SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN | SYSCTL_XTAL_16MHZ); // // The I2C0 peripheral must be enabled before use. // SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C0); // // For this example I2C0 is used with PortB[3:2]. The actual port and // pins used may be different on your part, consult the data sheet for // more information. GPIO port B needs to be enabled so these pins can // be used. // TODO: change this to whichever GPIO port you are using. // SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB); // // Configure the pin muxing for I2C0 functions on port B2 and B3. // This step is not necessary if your part does not support pin muxing. // TODO: change this to select the port/pin you are using. // GPIOPinConfigure(GPIO_PB2_I2C0SCL); GPIOPinConfigure(GPIO_PB3_I2C0SDA); // // Select the I2C function for these pins. This function will also // configure the GPIO pins pins for I2C operation, setting them to // open-drain operation with weak pull-ups. Consult the data sheet // to see which functions are allocated per pin. // TODO: change this to select the port/pin you are using. // GPIOPinTypeI2CSCL(GPIO_PORTB_BASE, GPIO_PIN_2); GPIOPinTypeI2C(GPIO_PORTB_BASE, GPIO_PIN_3); // // Enable loopback mode. Loopback mode is a built in feature that is // useful for debugging I2C operations. It internally connects the I2C // master and slave terminals, which effectively let's you send data as // a master and receive data as a slave. // NOTE: For external I2C operation you will need to use external pullups // that are stronger than the internal pullups. Refer to the datasheet for // more information. // HWREG(I2C0_BASE + I2C_O_MCR) |= 0x01; // // Enable and initialize the I2C0 master module. Use the system clock for // the I2C0 module. The last parameter sets the I2C data transfer rate. // If false the data rate is set to 100kbps and if true the data rate will // be set to 400kbps. For this example we will use a data rate of 100kbps. // I2CMasterInitExpClk(I2C0_BASE, SysCtlClockGet(), false); // // Enable the I2C0 slave module. This module is enabled only for testing // purposes. It does not need to be enabled for proper operation of the // I2Cx master module. // I2CSlaveEnable(I2C0_BASE); // // Set the slave address to SLAVE_ADDRESS. In loopback mode, it's an // arbitrary 7-bit number (set in a macro above) that is sent to the // I2CMasterSlaveAddrSet function. // I2CSlaveInit(I2C0_BASE, SLAVE_ADDRESS); // // Tell the master module what address it will place on the bus when // communicating with the slave. Set the address to SLAVE_ADDRESS // (as set in the slave module). The receive parameter is set to false // which indicates the I2C Master is initiating a writes to the slave. If // true, that would indicate that the I2C Master is initiating reads from // the slave. // I2CMasterSlaveAddrSet(I2C0_BASE, SLAVE_ADDRESS, false); // // Set up the serial console to use for displaying messages. This is // just for this example program and is not needed for I2C operation. // InitConsole(); // // Display the example setup on the console. // UARTprintf("I2C Loopback Example ->"); UARTprintf("n Module = I2C0"); UARTprintf("n Mode = Single Send/Receive"); UARTprintf("n Rate = 100kbpsnn"); // // Initalize the data to send. // pui32DataTx[0] = 'I'; pui32DataTx[1] = '2'; pui32DataTx[2] = 'C'; // // Initalize the receive buffer. // for(ui32Index = 0; ui32Index < NUM_I2C_DATA; ui32Index++) [ pui32DataRx[ui32Index] = 0; ] // // Indicate the direction of the data. // UARTprintf("Tranferring from: Master -> Slaven"); // // Send 3 peices of I2C data from the master to the slave. // for(ui32Index = 0; ui32Index < NUM_I2C_DATA; ui32Index++) [ // // Display the data that the I2C0 master is transferring. // UARTprintf(" Sending: '%c' . . . ", pui32DataTx[ui32Index]); // // Place the data to be sent in the data register // I2CMasterDataPut(I2C0_BASE, pui32DataTx[ui32Index]); // // Initiate send of data from the master. Since the loopback // mode is enabled, the master and slave units are connected // allowing us to receive the same data that we sent out. // I2CMasterControl(I2C0_BASE, I2C_MASTER_CMD_SINGLE_SEND); // // Wait until the slave has received and acknowledged the data. // while(!(I2CSlaveStatus(I2C0_BASE) & I2C_SLAVE_ACT_RREQ)) [ ] // // Read the data from the slave. // pui32DataRx[ui32Index] = I2CSlaveDataGet(I2C0_BASE); // // Wait until master module is done transferring. // while(I2CMasterBusy(I2C0_BASE)) [ ] // // Display the data that the slave has received. // UARTprintf("Received: '%c'n", pui32DataRx[ui32Index]); ] // // Reset receive buffer. // for(ui32Index = 0; ui32Index < NUM_I2C_DATA; ui32Index++) [ pui32DataRx[ui32Index] = 0; ] // // Indicate the direction of the data. // UARTprintf("nnTranferring from: Slave -> Mastern"); // // Modifiy the data direction to true, so that seeing the address will // indicate that the I2C Master is initiating a read from the slave. // I2CMasterSlaveAddrSet(I2C0_BASE, SLAVE_ADDRESS, true); // // Do a dummy receive to make sure you don't get junk on the first receive. // I2CMasterControl(I2C0_BASE, I2C_MASTER_CMD_SINGLE_RECEIVE); // // Dummy acknowledge and wait for the receive request from the master. // This is done to clear any flags that should not be set. // while(!(I2CSlaveStatus(I2C0_BASE) & I2C_SLAVE_ACT_TREQ)) [ ] for(ui32Index = 0; ui32Index < NUM_I2C_DATA; ui32Index++) [ // // Display the data that I2C0 slave module is transferring. // UARTprintf(" Sending: '%c' . . . ", pui32DataTx[ui32Index]); // // Place the data to be sent in the data register // I2CSlaveDataPut(I2C0_BASE, pui32DataTx[ui32Index]); // // Tell the master to read data. // I2CMasterControl(I2C0_BASE, I2C_MASTER_CMD_SINGLE_RECEIVE); // // Wait until the slave is done sending data. // while(!(I2CSlaveStatus(I2C0_BASE) & I2C_SLAVE_ACT_TREQ)) [ ] // // Read the data from the master. // pui32DataRx[ui32Index] = I2CMasterDataGet(I2C0_BASE); // // Display the data that the slave has received. // UARTprintf("Received: '%c'n", pui32DataRx[ui32Index]); ] // // Tell the user that the test is done. // UARTprintf("nDone.nn"); // // Return no errors // return(0);]
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