以下是初始化代码:
ROM_SysCtlClockSet(SYSCTL_SYSDIV_2_5 | SYSCTL_USE_PLL | SYSCTL_XTAL_16MHZ | //80mhz
SYSCTL_OSC_MAIN);
SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C0);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
GPIOPinConfigure(GPIO_PB2_I2C0SCL);
GPIOPinConfigure(GPIO_PB3_I2C0SDA);
GPIOPinTypeI2C(GPIO_PORTB_BASE, GPIO_PIN_3);
GPIOPinTypeI2CSCL(GPIO_PORTB_BASE, GPIO_PIN_2 );
I2CMasterInitExpClk(I2C0_MASTER_BASE, SysCtlClockGet(), true); //400kbps
ROM_SysCtlDelay(10000);
I2CMasterEnable(I2C0_MASTER_BASE);
以下是读取传感器(MPU6050)的两个寄存器0X3B,0X39,连续读取.Burst read,
unsigned long back1,back2,m;
I2CMasterSlaveAddrSet(I2C0_MASTER_BASE,SlaveAddress,false);
I2CMasterDataPut(I2C0_MASTER_BASE,0x38);
I2CMasterControl(I2C0_MASTER_BASE,I2C_MASTER_CMD_BURST_SEND_START);
while(I2CMasterBusy(I2C0_MASTER_BASE));
I2CMasterSlaveAddrSet(I2C0_MASTER_BASE,SlaveAddress,true);
I2CMasterControl(I2C0_MASTER_BASE,I2C_MASTER_CMD_BURST_RECEIVE_START);
while(I2CMasterBusy(I2C0_MASTER_BASE));
back1=I2CMasterDataGet(I2C0_MASTER_BASE);
I2CMasterControl(I2C0_MASTER_BASE,I2C_MASTER_CMD_BURST_RECEIVE_FINISH);
while(I2CMasterBusy(I2C0_MASTER_BASE));
back2=I2CMasterDataGet(I2C0_MASTER_BASE);
m=(back2<<8)|back1;
return(m);
back1可以正确的读出,为什么BACK2读不出来呢?是unavailable.
