TM4C129 I2C读取TMP100的温度问题

I2CMasterSlaveAddrSet( I2C6_BASE, 0x4A, true);										//控制传输方向为主机写
		I2CMasterDataPut( I2C6_BASE, 0x01 );												//写入主机数据(TMP100控制寄存器地址)
		I2CMasterControl( I2C6_BASE, I2C_MASTER_CMD_BURST_SEND_START );						//start+从机地址+主机数据传输
		while( I2CMasterErr(I2C6_BASE) | I2CMasterBusy(I2C6_BASE) );
		I2CMasterDataPut( I2C6_BASE, 0xED  ); 												//写入主机数据(TMP100控制寄存器内容)
		I2CMasterControl( I2C6_BASE, I2C_MASTER_CMD_BURST_SEND_CONT );					//主机数据传输
		while( I2CMasterErr(I2C6_BASE) | I2CMasterBusy(I2C6_BASE) );
		delay_ms(35);
		I2CMasterDataPut( I2C6_BASE, 0x00 ); 												//读取温度
		I2CMasterControl( I2C6_BASE, I2C_MASTER_CMD_BURST_SEND_FINISH ); 							//start+从机地址+主机数据+stop传输
		while( I2CMasterErr(I2C6_BASE) | I2CMasterBusy(I2C6_BASE) );
		delay_ms(25);

		I2CMasterSlaveAddrSet( I2C6_BASE, 0x4A, true);										//控制传输方向为主机写
		I2CMasterControl( I2C6_BASE, I2C_MASTER_CMD_BURST_RECEIVE_START );
		while( I2CMasterErr(I2C6_BASE) | I2CMasterBusy(I2C6_BASE) );		
		Result_H = I2CMasterDataGet( I2C6_BASE ); 													
		delay_ms(325);

		I2CMasterControl( I2C6_BASE, I2C_MASTER_CMD_BURST_RECEIVE_FINISH ); 							//start+从机地址+主机数据+stop传输
		while( I2CMasterErr(I2C6_BASE) | I2CMasterBusy(I2C6_BASE) );
		delay_ms(325);		
		Result_L = I2CMasterDataGet( I2C6_BASE ); 													//读出转换结果的低八位
		delay_ms(325);

为什么用100kHz的频率读不了数据？设置的精度是0.0625度，为什么每次温度变化是0.5度？

xyz549040622：

I2C初始化的部分有错误，TM4C 对初始化的时序很严格的，建议按照官方的来

uint32_t ui32DataTx;//// 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 helps// for debug the I2Cx module.It internally connects the I2C master and// slave terminals, which effectively lets you send data as a master and// receive data as a slave.NOTE: For external I2C operation you will need// to use external pull-ups that are faster than the internal pull-ups.// Refer to the datasheet for more information.//HWREG(I2C0_BASE + I2C_O_MCR) |= 0x01;//// Enable the I2C0 interrupt on the processor (NVIC).//IntEnable(INT_I2C0);//// Configure and turn on the I2C0 slave interrupt.The I2CSlaveIntEnableEx()// gives you the ability to only enable specific interrupts.For this case// we are only interrupting when the slave device receives data.//I2CSlaveIntEnableEx(I2C0_BASE, I2C_SLAVE_INT_DATA);//// 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.//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 proper I2C operation.//InitConsole();//// Enable interrupts to the processor.//IntMasterEnable();

Sparrow：

回复 xyz549040622:

这个官方的例程是TM4C129吗？ 我记得129的时钟配置应该是

ui32SysClock = MAP_SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |SYSCTL_OSC_MAIN | SYSCTL_USE_PLL |SYSCTL_CFG_VCO_480), 120000000);

还有 HWREG(I2C0_BASE + I2C_O_MCR) |= 0x01;只在循环模式才配置的。

xyz549040622：

回复 Sparrow:

这个应该是TM4123中的，我指的是这句

  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);
只能一步一步排除错误了。不知道你调试到哪一步了，如果有个逻辑分析仪就更好了

jx Wang1：

100K是可以的，是参数没有正确写入。

Sparrow：

回复 jx Wang1:

配置参数吗？