一个稳定可靠的STM32I2C程序解析（精编版）

1、/*file : i2c.hpurpose : */#ifndef _i2c_h_#define _i2c_h_/* includes */* defines */#define sensors_i2c i2c2#define i2c_speed 400000#define i2c_own_address 0 x00#define i2c_config() i2cmaster_init();/* prototypes */void i2cmaster_init(void);unsigned long sensors_i2c_writeregister(unsigned char address

2、, unsigned char registeraddr, unsigned short registerlen, const unsigned char *registervalue);unsigned long sensors_i2c_readregister(unsigned char address, unsigned char registeraddr, unsigned short registerlen, unsigned char *registervalue);int sensors_i2c_writeregister_swap(unsigned char slave_add

3、r,unsigned char reg_addr,unsigned char len, unsigned char *data_ptr);int sensors_i2c_readregister_swap(unsigned char slave_addr,unsigned char reg_addr,unsigned char len, unsigned char *data_ptr);int i2c_reset_user();#endif / _i2c_h_/*file : i2c.cpurpose : i2c 3 to communicate with the sensorsauthor

4、: * includes */#include #include stm32l1xx.h#include i2c.h#include gpio.h#include log.h#include discover_board.h#include main.h/* defines */#define i2cx_flag_timeout (uint32_t) 900)#define i2cx_long_timeout (uint32_t)(300 * i2cx_flag_timeout)#define sensors_i2c_scl_gpio_port gpiob#define sensors_i2c

5、_scl_gpio_clk rcc_ahbperiph_gpiob#define sensors_i2c_scl_gpio_pin gpio_pin_10#define sensors_i2c_scl_gpio_pinsource gpio_pinsource10#define sensors_i2c_sda_gpio_port gpiob#define sensors_i2c_sda_gpio_clk rcc_ahbperiph_gpiob#define sensors_i2c_sda_gpio_pin gpio_pin_11#define sensors_i2c_sda_gpio_pins

6、ource gpio_pinsource11#define sensors_i2c_rcc_clk rcc_apb1periph_i2c2#define sensors_i2c_af gpio_af_i2c2#define wait_for_flag(flag, value, timeout, errorcode) #define clear_addr_bit /* globals */* prototypes */* function */static uint32_t i2cx_timeout_usercallback(char value);void i2cmaster_init(voi

7、d)gpio_inittypedef gpio_initstructure;i2c_inittypedef i2c_initstructure;/* enable i2cx clock */rcc_apb1periphclockcmd(sensors_i2c_rcc_clk, enable);/* enable i2c gpio clock */rcc_ahbperiphclockcmd(sensors_i2c_scl_gpio_clk | sensors_i2c_sda_gpio_clk, enable);/* configure i2cx pin: scl -*/gpio_initstru

8、cture.gpio_pin = sensors_i2c_scl_gpio_pin; gpio_initstructure.gpio_mode = gpio_mode_af;gpio_initstructure.gpio_speed = gpio_speed_10mhz;gpio_initstructure.gpio_otype = gpio_otype_od;gpio_initstructure.gpio_pupd = gpio_pupd_nopull;/* connect pins to periph */gpio_pinafconfig(sensors_i2c_scl_gpio_port

9、, sensors_i2c_scl_gpio_pinsource, sensors_i2c_af); gpio_init(sensors_i2c_scl_gpio_port, &gpio_initstructure);/* configure i2cx pin: sda -*/gpio_initstructure.gpio_pin = sensors_i2c_sda_gpio_pin; /* connect pins to periph */gpio_pinafconfig(sensors_i2c_sda_gpio_port, sensors_i2c_sda_gpio_pinsourc

10、e, sensors_i2c_af); gpio_init(sensors_i2c_sda_gpio_port, &gpio_initstructure); i2c_deinit(sensors_i2c);i2c_initstructure.i2c_mode = i2c_mode_i2c;i2c_initstructure.i2c_dutycycle = i2c_dutycycle_2;i2c_initstructure.i2c_ownaddress1 = i2c_own_address;i2c_initstructure.i2c_ack = i2c_ack_enable;i2c_in

11、itstructure.i2c_acknowledgedaddress = i2c_acknowledgedaddress_7bit;i2c_initstructure.i2c_clockspeed = i2c_speed;/* enable the i2c peripheral */i2c_cmd(sensors_i2c, enable); /* initialize the i2c peripheral */i2c_init(sensors_i2c, &i2c_initstructure);/* brief basic management of the timeout situa

12、tion.* param none.* retval none.*/static uint32_t i2cx_timeout_usercallback(char value)/* the following code allows i2c error recovery and return to normal communicationif the error source doesnt still exist (ie. hardware issue.) */i2c_inittypedef i2c_initstructure;i2c_generatestop(sensors_i2c, enab

13、le);i2c_softwareresetcmd(sensors_i2c, enable);i2c_softwareresetcmd(sensors_i2c, disable);i2c_deinit(sensors_i2c);i2c_initstructure.i2c_mode = i2c_mode_i2c;i2c_initstructure.i2c_dutycycle = i2c_dutycycle_2;i2c_initstructure.i2c_ownaddress1 = i2c_own_address;i2c_initstructure.i2c_ack = i2c_ack_enable;

14、i2c_initstructure.i2c_acknowledgedaddress = i2c_acknowledgedaddress_7bit;i2c_initstructure.i2c_clockspeed = i2c_speed;/* enable the i2c peripheral */i2c_cmd(sensors_i2c, enable); /* initialize the i2c peripheral */i2c_init(sensors_i2c, &i2c_initstructure);#ifdef user_debug mpl_logi(i2c restarted

15、.n);#endifreturn 1;int i2c_reset_user()return i2cx_timeout_usercallback(0); /* brief writes a byte to a given register to the sensors through the control interface (i2c)* param registeraddr: the address (location) of the register to be written.* param registervalue: the byte value to be written into

16、 destination register.* retval 0 if correct communication, else wrong communication*/unsigned long sensors_i2c_writeregister(unsigned char address, unsigned char registeraddr, unsigned short registerlen, const unsigned char *registervalue)uint32_t result = 0;uint32_t i = registerlen;_io uint32_t i2c

17、timeout = i2cx_long_timeout;/registervalue = registervalue + (registerlen - 1);/* wait for the busy flag to be cleared */wait_for_flag (i2c_flag_busy, reset, i2cx_long_timeout, 1);/* start the config sequence */i2c_generatestart(sensors_i2c, enable);/* wait for the start bit to be set */wait_for_fla

18、g (i2c_flag_sb, set, i2cx_flag_timeout, 2);/* transmit the slave address and enable writing operation */i2c_send7bitaddress(sensors_i2c, (address1), i2c_direction_transmitter);/* wait for address bit to be set */wait_for_flag (i2c_flag_addr, set, i2cx_flag_timeout, 3);/* clear the addr interrupt bit

19、 - this is done by reading sr1 and sr2*/clear_addr_bit/* wait for address bit to be set */wait_for_flag (i2c_flag_txe, set, i2cx_flag_timeout, 4);/* transmit the first address for write operation */i2c_senddata(sensors_i2c, registeraddr);while (i-)/* wait for address bit to be set */wait_for_flag (i

20、2c_flag_txe, set, i2cx_flag_timeout, 5);/* prepare the register value to be sent */i2c_senddata(sensors_i2c, *registervalue-);i2c_senddata(sensors_i2c, *registervalue+);/* wait for address bit to be set */wait_for_flag (i2c_flag_btf, set, i2cx_flag_timeout, 6);/* end the configuration sequence */i2c

21、_generatestop(sensors_i2c, enable); /* return the verifying value: 0 (passed) or 1 (failed) */return result; unsigned long sensors_i2c_readregister(unsigned char address, unsigned char registeraddr, unsigned short registerlen, unsigned char *registervalue)uint32_t result = 0;uint8_t bytesremaining =

22、 registerlen;_io uint32_t i2ctimeout = i2cx_long_timeout;/* wait for the busy flag to be cleared */wait_for_flag (i2c_flag_busy, reset, i2cx_long_timeout, 7);/* start the config sequence */i2c_generatestart(sensors_i2c, enable);/* wait for the start bit to be set */wait_for_flag (i2c_flag_sb, set, i

23、2cx_flag_timeout, 8);/* transmit the slave address and enable writing operation */i2c_send7bitaddress(sensors_i2c, (address1), i2c_direction_transmitter);/* wait for the start bit to be set */wait_for_flag (i2c_flag_addr, set, i2cx_flag_timeout, 9);/* clear the addr interrupt bit - this is done by r

24、eading sr1 and sr2*/clear_addr_bit;/* wait for address bit to be set */wait_for_flag (i2c_flag_txe, set, i2cx_flag_timeout, 10);/* transmit the register address to be read */i2c_senddata(sensors_i2c, registeraddr);/* wait for address bit to be set */wait_for_flag (i2c_flag_txe, set, i2cx_flag_timeou

25、t, 11); /*! send start condition a second time */ i2c_generatestart(sensors_i2c, enable);/* wait for the start bit to be set */wait_for_flag (i2c_flag_sb, set, i2cx_flag_timeout, 12);/*! send address for read */i2c_send7bitaddress(sensors_i2c, (address1), i2c_direction_receiver); /* wait for the sta

26、rt bit to be set */wait_for_flag (i2c_flag_addr, set, i2cx_flag_timeout, 13);if (registerlen = 1) /*! disable acknowledgment */i2c_acknowledgeconfig(sensors_i2c, disable);/* clear the addr interrupt bit - this is done by reading sr1 and sr2*/clear_addr_bit;/*! send stop condition */i2c_generatestop(

27、sensors_i2c, enable);/* wait for the rxne bit to be set */wait_for_flag (i2c_flag_rxne, set, i2cx_flag_timeout, 14);/bytesremaining-;/registervaluebytesremaining = i2c_receivedata(sensors_i2c);registervalue0 = i2c_receivedata(sensors_i2c); else if( registerlen = 2) /*!cr1 |= i2c_cr1_pos;/* clear the

28、 addr interrupt bit - this is done by reading sr1 and sr2*/clear_addr_bit; /* wait for the buffer full bit to be set */wait_for_flag (i2c_flag_btf, set, i2cx_flag_timeout, 15);/*! send stop condition */i2c_generatestop(sensors_i2c, enable);/* read 2 bytes */bytesremaining-;/registervaluebytesremaini

29、ng = i2c_receivedata(sensors_i2c);/registervaluebytesremaining = i2c_receivedata(sensors_i2c);registervalue0 = i2c_receivedata(sensors_i2c);registervalue1 = i2c_receivedata(sensors_i2c); else /* more than 2 bytes */* clear the addr interrupt bit - this is done by reading sr1 and sr2*/clear_addr_bit;

30、while(bytesremaining)if( bytesremaining = 3)/* wait for the buffer full bit to be set */wait_for_flag (i2c_flag_btf, set, i2cx_flag_timeout, 16);/*! disable acknowledgment */i2c_acknowledgeconfig(sensors_i2c, disable);/* read 1 bytes */bytesremaining-;/registervaluebytesremaining = i2c_receivedata(s

31、ensors_i2c);*registervalue+ = i2c_receivedata(sensors_i2c);/*! send stop condition */i2c_generatestop(sensors_i2c, enable); /* read 1 bytes */bytesremaining-;/registervaluebytesremaining = i2c_receivedata(sensors_i2c);*registervalue+ = i2c_receivedata(sensors_i2c);/* wait for the buffer full bit to

32、be set */wait_for_flag (i2c_flag_rxne, set, i2cx_flag_timeout, 17);/* read 1 bytes */bytesremaining-;/registervaluebytesremaining = i2c_receivedata(sensors_i2c); *registervalue+ = i2c_receivedata(sensors_i2c);else/* wait for the rxne bit to be set */wait_for_flag (i2c_flag_rxne, set, i2cx_flag_timeo

33、ut, 18);/* read 2 bytes */bytesremaining-;/registervaluebytesremaining = i2c_receivedata(sensors_i2c); *registervalue+ = i2c_receivedata(sensors_i2c); /* clear btf flag */i2c_clearflag(sensors_i2c, i2c_flag_btf);/* wait for the busy flag to be cleared */wait_for_flag (i2c_flag_busy, reset, i2cx_long_timeout, 19); /*!cr1 &=