forked from logzhan/RobotHardware-UESTC
159 lines
2.8 KiB
C
159 lines
2.8 KiB
C
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#ifdef __cplusplus
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extern "C" {
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#endif
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#include "i2c.h"
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static void I2C_delay()
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{
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volatile int i = 17;
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while (i)
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i--;
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}
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static int HC_I2C_Start()
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{
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HC_SDA_H;
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HC_SCL_H;
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I2C_delay();
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if (!SDA_read)
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return 0;
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HC_SDA_L;
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I2C_delay();
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if (HC_SDA_read)
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return 0;
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HC_SDA_L;
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I2C_delay();
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return 1;
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}
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static void HC_I2C_Stop()
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{
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HC_SCL_L;
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I2C_delay();
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HC_SDA_L;
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I2C_delay();
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HC_SCL_H;
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I2C_delay();
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HC_SDA_H;
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I2C_delay();
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}
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static void HC_I2C_NoAck()
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{
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HC_SCL_L;
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I2C_delay();
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HC_SDA_H;
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I2C_delay();
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HC_SCL_H;
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I2C_delay();
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HC_SCL_L;
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I2C_delay();
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}
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static int HC_I2C_WaitAck()
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{
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HC_SCL_L;
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I2C_delay();
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HC_SDA_H;
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I2C_delay();
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HC_SCL_H;
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I2C_delay();
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if (HC_SDA_read) {
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HC_SCL_L;
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return 0;
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}
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HC_SCL_L;
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return 1;
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}
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static void HC_I2C_SendByte(uint8_t b)
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{
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uint8_t i = 8;
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while (i--) {
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HC_SCL_L;
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I2C_delay();
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if (b & 0x80)
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HC_SDA_H;
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else
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HC_SDA_L;
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b <<= 1;
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I2C_delay();
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HC_SCL_H;
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I2C_delay();
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}
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HC_SCL_L;
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}
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static uint8_t HC_I2C_ReadByte()
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{
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uint8_t i = 8;
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uint8_t byte = 0;
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HC_SDA_H;
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while (i--) {
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byte <<= 1;
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HC_SCL_L;
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I2C_delay();
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HC_SCL_H;
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I2C_delay();
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if (HC_SDA_read) {
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byte |= 0x01;
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}
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}
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HC_SCL_L;
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return byte;
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}
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void HC_I2C_Init(void)
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{
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GPIO_InitTypeDef GPIO_InitStruct;
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// 使能GPIOB时钟
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__HAL_RCC_GPIOB_CLK_ENABLE();
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GPIO_InitStruct.Pin = GPIO_PIN_0; // SCL
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GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD; // 开漏输出
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GPIO_InitStruct.Pull = GPIO_PULLUP; // 使用上拉
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HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
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GPIO_InitStruct.Pin = GPIO_PIN_1; // SDA
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GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD; // 开漏输出
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GPIO_InitStruct.Pull = GPIO_PULLUP; // 使用上拉
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HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
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}
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void HC_I2C_Write()
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{
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HC_I2C_Start();
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HC_I2C_SendByte(0xAE);
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HC_I2C_WaitAck();
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HC_I2C_SendByte(0x01);
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HC_I2C_WaitAck();
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HC_I2C_Stop();
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}
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int HC_I2C_Read()
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{
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unsigned int BYTE_H=0, BYTE_M=0, BYTE_L=0;
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float distance=0;//测距距离
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//读数据-地址为0xAF
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if (!HC_I2C_Start())
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return 0;
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HC_I2C_SendByte(0xAF);
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if (!HC_I2C_WaitAck()) {
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HC_I2C_Stop();
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return 0;
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}
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BYTE_H=HC_I2C_ReadByte();//读数据
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HC_I2C_WaitAck();
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BYTE_M=HC_I2C_ReadByte();//读数据
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HC_I2C_WaitAck();
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BYTE_L=HC_I2C_ReadByte();//读数据
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HC_I2C_NoAck();
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HC_I2C_Stop();
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distance=((BYTE_H*65536)+(BYTE_M*256)+BYTE_L)/1000.0f;//单位mm
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return distance;
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}
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