msp432使用软件i2c的示例代码
时间: 2023-12-10 14:41:10 浏览: 18
下面是一个使用软件I2C的MSP432示例代码:
```c
#include <msp.h>
#include <stdint.h>
#define I2C_SDA_PORT P1
#define I2C_SDA_PIN BIT6
#define I2C_SCL_PORT P1
#define I2C_SCL_PIN BIT7
#define I2C_DELAY_US 10
void i2c_init(void) {
I2C_SDA_PORT->SEL0 &= ~I2C_SDA_PIN;
I2C_SDA_PORT->SEL1 &= ~I2C_SDA_PIN;
I2C_SCL_PORT->SEL0 &= ~I2C_SCL_PIN;
I2C_SCL_PORT->SEL1 &= ~I2C_SCL_PIN;
I2C_SDA_PORT->DIR |= I2C_SDA_PIN;
I2C_SCL_PORT->DIR |= I2C_SCL_PIN;
I2C_SDA_PORT->OUT |= I2C_SDA_PIN;
I2C_SCL_PORT->OUT |= I2C_SCL_PIN;
}
void i2c_start(void) {
I2C_SDA_PORT->DIR |= I2C_SDA_PIN;
I2C_SDA_PORT->OUT |= I2C_SDA_PIN;
I2C_SCL_PORT->OUT |= I2C_SCL_PIN;
__delay_cycles(I2C_DELAY_US);
I2C_SDA_PORT->OUT &= ~I2C_SDA_PIN;
__delay_cycles(I2C_DELAY_US);
I2C_SCL_PORT->OUT &= ~I2C_SCL_PIN;
}
void i2c_stop(void) {
I2C_SDA_PORT->DIR |= I2C_SDA_PIN;
I2C_SDA_PORT->OUT &= ~I2C_SDA_PIN;
I2C_SCL_PORT->OUT |= I2C_SCL_PIN;
__delay_cycles(I2C_DELAY_US);
I2C_SDA_PORT->OUT |= I2C_SDA_PIN;
__delay_cycles(I2C_DELAY_US);
}
void i2c_send_byte(uint8_t byte) {
uint8_t bit;
I2C_SDA_PORT->DIR |= I2C_SDA_PIN;
for (bit = 0; bit < 8; bit++) {
if (byte & 0x80) {
I2C_SDA_PORT->OUT |= I2C_SDA_PIN;
} else {
I2C_SDA_PORT->OUT &= ~I2C_SDA_PIN;
}
byte <<= 1;
I2C_SCL_PORT->OUT |= I2C_SCL_PIN;
__delay_cycles(I2C_DELAY_US);
I2C_SCL_PORT->OUT &= ~I2C_SCL_PIN;
__delay_cycles(I2C_DELAY_US);
}
}
uint8_t i2c_receive_byte(void) {
uint8_t byte = 0;
uint8_t bit;
I2C_SDA_PORT->DIR &= ~I2C_SDA_PIN;
for (bit = 0; bit < 8; bit++) {
byte <<= 1;
I2C_SCL_PORT->OUT |= I2C_SCL_PIN;
__delay_cycles(I2C_DELAY_US);
if (I2C_SDA_PORT->IN & I2C_SDA_PIN) {
byte |= 0x01;
}
I2C_SCL_PORT->OUT &= ~I2C_SCL_PIN;
__delay_cycles(I2C_DELAY_US);
}
return byte;
}
void i2c_write_byte(uint8_t address, uint8_t reg, uint8_t data) {
i2c_start();
i2c_send_byte(address);
i2c_send_byte(reg);
i2c_send_byte(data);
i2c_stop();
}
uint8_t i2c_read_byte(uint8_t address, uint8_t reg) {
uint8_t data;
i2c_start();
i2c_send_byte(address);
i2c_send_byte(reg);
i2c_start();
i2c_send_byte(address | 0x01);
data = i2c_receive_byte();
i2c_stop();
return data;
}
```
这个代码中实现了软件I2C的初始化、发送和接收字节的函数。你可以根据自己的需要修改这个代码来使用。注意,这个代码只是一个示例,需要根据你的具体情况进行修改。