i2c 通信 问题 总是在while(I2caRegs.I2CSTR.bit.XRDY == 0) 一直卡主

i2c 通信 问题 总是在while(I2caRegs.I2CSTR.bit.XRDY == 0) 一直卡主

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  • 秀才10分

    我打算使用TI F28335开发板读取一个湿度传感器的数据,通过I2C 通信。 我附上修改后的程序(基于TI官方的给F28335写的I2C的一个例子程序),发现这个例子程序并不可以运行。每次都是卡在 while(I2caRegs.I2CSTR.bit.XRDY == 0); // wait until first byte is out 这条语句无线循环,并不能继续执行下去。这个问题困扰我很久,是因为这个例子程序本身就有问题吗?还是因为其他原因? 这个传感器我目前使用的datasheet的PDF文件链接如下:https://www.pololu.com/file/0J721/HTU21D(F).pdf 方便您参考。 通信中使用的register还有地址我都严格按照datasheet上面所说应该都没有问题,build这个程序过程中也并没有报错,所以完全不知道我这个程序问题出在哪里。 传感器我使用的是adafruit家已经做好的breakout board,应该已经包括pull up resistor。 这个硬件链接在这里:https://learn.adafruit.com/adafruit-htu21d-f-temperature-humidity-sensor/overview

    //
    //      Lab12_2: TMS320F28335
    //      (C) Frank Bormann
    //
    //###########################################################################
    //
    // FILE:	Lab12_2.c
    //
    // TITLE:	DSP28335 I2C test
    //          Temperature Sensor TMP100 connected to GPIO33 (SCL) and GPIO32(SDA)
    //			LED GPIO34 as life indicator 100 ms toggle
    //			12 bit mode of TMP100, 1/16 degree celcius resolution
    //			use watch window for variable "temperature" (type int; qvalue:8)
    //###########################################################################
    //
    //  Ver | dd mmm yyyy | Who  | Description of changes
    // =====|=============|======|===============================================
    //  3.0 | 24 Jul 2009 | F.B. | Lab12_1  F28335; Header-files Version 1.20 
    //  3.1 | 15 Nov 2009 | F.B  | Lab12_1 for F28335 @30MHz and PE revision 5
    //###########################################################################
    #include "DSP2833x_Device.h"
    
    #define SLAVE_Address 			0x40	
    
    
    #define SLAVE_Write      0x80
    #define SLAVE_READ       0x81
    #define SLAVE_Write_humidity      0xE5
    
    // external function prototypes
    extern void InitSysCtrl(void);
    extern void InitPieCtrl(void);
    extern void InitPieVectTable(void);
    extern void InitCpuTimers(void);
    extern void ConfigCpuTimer(struct CPUTIMER_VARS *, float, float);
    
    
    // Prototype statements for functions found within this file.
    void Gpio_select(void);
    void I2CA_Init(void);
    interrupt void cpu_timer0_isr(void);
    
    int Value_Read;
    
    //###########################################################################
    //						main code									
    //###########################################################################
    void main(void)
    {
    	InitSysCtrl();		// Basic Core Init from DSP2833x_SysCtrl.c
    
    	EALLOW;
       	SysCtrlRegs.WDCR= 0x00AF;	// Re-enable the watchdog 
       	EDIS;			// 0x00AF  to NOT disable the Watchdog, Prescaler = 64
    
    	DINT;			// Disable all interrupts
    	
    	Gpio_select();	// GPI031-LED2, GPIO34-LED3 as output
    					// to 2 LEDs on F28335 control-card
    
    	I2CA_Init(); 	//	Initialize I2C device slave address is issued in I2CA_Init() 0x29
    
    	// step 1 : do the configuration:
    	//----------------------------------------------------//
    	// Send START, set pointer to Configuration register and set resolution to 12 bit
    	//hence it is master-transmitter mode to write register to the sensor
    
    	//step 1.1 set integration time to address 0x01+0xFF (2.4ms)
    
    	//step 1.2 set gain to address 0x0F + 0x00 (1*gain)
    
    	//step 1.3 Enable Device to address 0x00+0x03
    
    
    	I2caRegs.I2CCNT = 2;	// means the DXR includes 2 byte including POINTER_CONFIGURATION and 0x60 for data bit setting
    	I2caRegs.I2CDXR = SLAVE_Write;// address for writing
    
    	I2caRegs.I2CMDR.all = 0x6E20; //0x6E20 convert to binary is 0110111000100000
    	/*
            Bit15 = 0;	no NACK in receiver mode
    		Bit14 = 1;  FREE on emulation halt
    		Bit13 = 1;  STT  generate START 
    		Bit12 = 0;	reserved
    		Bit11 = 1;  STP  generate STOP
    		Bit10 = 1;  MST  master mode
    		Bit9  = 1;  TRX  ****master - transmitter mode****
    		Bit8  = 0;	XA   7 bit address mode
    		Bit7  = 0;  RM   nonrepeat mode, I2CCNT determines # of bytes
    		Bit6  = 1;  DLB  no loopback mode.it should be '0', from slide 12-12 corrected by Alex.J. 
    		Bit5  = 1;  IRS  I2C module enabled
    		Bit4  = 0;  STB  no start byte mode
    		Bit3  = 0;  FDF  no free data format
    		Bit2-0: 0;  BC  **** 8 bit per data byte****
    	*/
    	while(I2caRegs.I2CSTR.bit.XRDY == 0);		// wait until first byte is out
    
    	I2caRegs.I2CDXR = SLAVE_Write_humidity ;   /*0xE5 read humidity       */
    
    	while(I2caRegs.I2CSTR.bit.SCD == 0);			// wait for STOP condition
    		
    	I2caRegs.I2CSTR.bit.SCD = 1; //clear stop condition flag
    
    	InitPieCtrl();		// basic setup of PIE table; from DSP2833x_PieCtrl.c
    	InitPieVectTable();	// default ISR's in PIE
    
    	EALLOW;
    	PieVectTable.TINT0 = &cpu_timer0_isr;
    	EDIS;
    
    	InitCpuTimers();	// basic setup CPU Timer0, 1 and 2
    	ConfigCpuTimer(&CpuTimer0,150,100000);
    
    	PieCtrlRegs.PIEIER1.bit.INTx7 = 1;
    
    	IER |=1;
    
    	EINT;
    	ERTM;
    
    	CpuTimer0Regs.TCR.bit.TSS = 0;	// start timer0
    
    	//step 2 : start read the sensor data including 1 byte pointer register==>2 byte sensor data (upper 8bit) + (lower 8bit)
    	while(1)
    	{    
    
    		    while(CpuTimer0.InterruptCount == 0);
    
    		    CpuTimer0.InterruptCount = 0;
    
    			EALLOW;
    			SysCtrlRegs.WDKEY = 0x55;	// service WD #1
    			EDIS;
    
    			//	Send START and set pointer to temperature - register
    			I2caRegs.I2CCNT 	= 1;				// pointer to temperature register, count 1 bit only
    			I2caRegs.I2CDXR		= SLAVE_READ;// address for reading
    
    			// Send start as master transmitter
    	 		I2caRegs.I2CMDR.all = 0x6620; //only change stop to '0', do not generate stop. all others are the same as 6E20
    			/*	Bit15 = 0;	no NACK in receiver mode
    				Bit14 = 1;  FREE on emulation halt
    				Bit13 = 1;  STT  generate START 
    				Bit12 = 0;	reserved
    				Bit11 = 0;  STP  not generate STOP
    				Bit10 = 1;  MST  master mode
    				Bit9  = 1;  TRX  master - transmitter mode
    				Bit8  = 0;	XA   7 bit address mode
    				Bit7  = 0;  RM   nonrepeat mode, I2CCNT determines # of bytes
    				Bit6  = 1;  DLB  no loopback mode ,it should be '0', corrected by alex.J
    				Bit5  = 1;  IRS  I2C module enabled
    				Bit4  = 0;  STB  no start byte mode
    				Bit3  = 0;  FDF  no free data format
    				Bit2-0: 0;  BC   8 bit per data byte,000	*/
    			while(I2caRegs.I2CSTR.bit.ARDY == 0);			// 0=previous cycle has not completed, wait for access ready condition
    
    			I2caRegs.I2CCNT		= 1;	// read 2 byte temperature
    			I2caRegs.I2CMDR.all = 0x6C20; //only change bit9 to 0, means master-receiver mode
    			/*	Bit15 = 0;	no NACK in receiver mode
    				Bit14 = 1;  FREE on emulation halt
    				Bit13 = 1;  STT  generate START 
    				Bit12 = 0;	reserved
    				Bit11 = 1;  STP  generate STOP
    				Bit10 = 1;  MST  master mode
    				Bit9  = 0;  TRX  master - receiver mode
    				Bit8  = 0;	XA   7 bit address mode
    				Bit7  = 0;  RM   nonrepeat mode, I2CCNT determines # of bytes
    				Bit6  = 0;  DLB  no loopback mode
    				Bit5  = 1;  IRS  I2C module enabled
    				Bit4  = 0;  STB  no start byte mode
    				Bit3  = 0;  FDF  no free data format
    				Bit2-0: 0;  BC   8 bit per data byte	*/
    
    			while(I2caRegs.I2CSTR.bit.RRDY == 0);	//0 means receive data NOT available in 12CDRR, wait for 1st byte
    			Value_Read = I2caRegs.I2CDRR; // read  8 Bit (integers)
    			// RRDY is automatically cleared by read of I2CDRR 
    
    	  		GpioDataRegs.GPBTOGGLE.bit.GPIO34 = 1;		// toggle red LED LD3 @ 28335CC
    	  		GpioDataRegs.GPATOGGLE.bit.GPIO31 = 1;
    	}
    } 
    
    void Gpio_select(void)
    {
    	EALLOW;
    	GpioCtrlRegs.GPAMUX1.all = 0;			// GPIO15 ... GPIO0 = General Puropse I/O
    	GpioCtrlRegs.GPAMUX2.all = 0;			// GPIO31 ... GPIO16 = General Purpose I/O
    	
    	GpioCtrlRegs.GPBMUX1.all = 0;			// GPIO47 ... GPIO32 = General Purpose I/O
    	GpioCtrlRegs.GPBMUX1.bit.GPIO32 = 1;	// GPIO32 = I2C - SDA
    	GpioCtrlRegs.GPBMUX1.bit.GPIO33 = 1;	// GPIO33 = I2C - SCL
    
    	GpioCtrlRegs.GPBPUD.bit.GPIO32 = 0;    // Enable pull-up for GPIO32 (SDAA)
    	GpioCtrlRegs.GPBPUD.bit.GPIO33 = 0;	   // Enable pull-up for GPIO33 (SCLA)
    
    	GpioCtrlRegs.GPBQSEL1.bit.GPIO32 = 3;  // Asynch input GPIO32 (SDAA)
        GpioCtrlRegs.GPBQSEL1.bit.GPIO33 = 3;  // Asynch input GPIO33 (SCLA)
    
    	GpioCtrlRegs.GPBMUX2.all = 0;			// GPIO63 ... GPIO48 = General Purpose I/O
    
    	GpioCtrlRegs.GPCMUX1.all = 0;			// GPIO79 ... GPIO64 = General Purpose I/O
    	GpioCtrlRegs.GPCMUX2.all = 0;			// GPIO87 ... GPIO80 = General Purpose I/O
    	 
    
    	GpioCtrlRegs.GPADIR.all = 0;			// GPIO0 to 31 as inputs
    //	GpioCtrlRegs.GPADIR.bit.GPIO9 = 1;		// GPIO9 = LED LD1
    	GpioCtrlRegs.GPADIR.bit.GPIO31 = 1;		// GpIO11 = LED LD2
    
    	GpioCtrlRegs.GPBDIR.all = 0;			// GPIO63-32 as inputs
    	GpioCtrlRegs.GPBDIR.bit.GPIO34 = 1;		// peripheral explorer: LED LD3 at GPIO34
    	//GpioCtrlRegs.GPBDIR.bit.GPIO49 = 1; 	// peripheral explorer: LED LD4 at GPIO49
    
    	GpioCtrlRegs.GPCDIR.all = 0;			// GPIO87-64 as inputs
    	EDIS;
    }  
    
    void I2CA_Init(void)
    {
    	
    	I2caRegs.I2CMDR.bit.IRS = 0;	// Reset the I2C module
    	// I2C slave address register
    	I2caRegs.I2CSAR = SLAVE_Address;
    	// I2C Prescale Register
    	I2caRegs.I2CPSC.all = 14;		// Internal I2C module clock = SYSCLK/(PSC +1)
    								    // = 10 MHz
    								    
        I2caRegs.I2CCLKL = 95;			// Tmaster = (PSC +1)[ICCL + 5 + ICCH + 5] / 150MHz
    	I2caRegs.I2CCLKH = 95;			// Tmaster =  10 [ICCL + ICCH + 10] / 150 MHz
    									// d = 5  for IPSC >1
    									
    									// for I2C 50 kHz:
    									// Tmaster = 20 µs *150 MHz / 10 = 200 = (ICCL + ICCH +10)  
    									// ICCL + ICCH = 190
    									// ICCL = ICH = 190/2 = 95	
    
    //	I2caRegs.I2CCLKL = 45;
    //	I2caRegs.I2CCLKH = 45;			// for I2C 100 kHz:
    									// Tmaster = 10 µs *150 MHz / 10 = 100 = (ICCL + ICCH + 10)  
    									// ICCL + ICCH = 90
    									// ICCL = ICH = 90/2 = 45 	
    
    	I2caRegs.I2CMDR.bit.IRS = 1;	// Take I2C out of reset
    }
    
    interrupt void cpu_timer0_isr(void)
    {
    	CpuTimer0.InterruptCount++;
    	EALLOW;
    	SysCtrlRegs.WDKEY = 0xAA;	// service WD #2
    	EDIS;
    	PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;
    }
    //===========================================================================
    // End of SourceCode.
    //===========================================================================
    
  • 探花11005分

    TI的官方例程是没有问题的。应该是你修改后出的问题。

    应该是你的数据没有发出去,你可以通过示波器测量SDA, CLK确认一下。

    如果此回复解答了您的问题,请在“ 这问题是否已被解答?” 点击 ” 是 “,谢谢!

  • 秀才10分

    你好!我也遇到同样的问题,请问你的问题解决了吗?怎么解决的?