1、SGM58031芯片详解
（1）SGM58031是一款低功耗，16位精度，delta-sigma (ΔΣ)模数转换器(ADC)。它从3V到5.5V供电。
（2）SGM58031包含一个片上参考和振荡器。它有一个I2C兼容接口，可以选择四个I2C从地址。
（3）SGM58031有两种工作模式：单次发射模式和连续转换模式。
在单次触发模式下，ADC执行一次转换并给出完整的固定数据，无需丢弃任何数据。一旦ADC完成转换，它就会进入低功率关闭模式。
在连续模式中，ADC在先前的转换完成后自动开始新的转换。给出了每一个转换结果。数据速率等于配置的数据速率。
（4）SGM58031的引脚说明
（5）参考电压
2、SGM58031工程代码编写
iic.c
#include "iic.h"#define I2C1_SLAVE_ADDRESS7 0x90void i2c_config(void)
{/* enable GPIOB clock */rcu_periph_clock_enable(RCU_GPIOB);/* enable I2C1 clock */rcu_periph_clock_enable(RCU_I2C1);rcu_periph_clock_enable(RCU_AF);/* connect PB10 to I2C1_SCL *//* connect PB11 to I2C1_SDA */gpio_init(GPIOB, GPIO_MODE_AF_OD, GPIO_OSPEED_50MHZ, GPIO_PIN_10 | GPIO_PIN_11);i2c_clock_config(I2C1, 100000, I2C_DTCY_2);i2c_mode_addr_config(I2C1, I2C_I2CMODE_ENABLE, I2C_ADDFORMAT_7BITS, I2C1_SLAVE_ADDRESS7);i2c_enable(I2C1);i2c_ack_config(I2C1, I2C_ACK_ENABLE);
}/* I2C写函数 */
void i2c_write(uint8_t reg_addr, uint16_t send_data)
{uint8_t high_val=0x00;uint8_t low_val=0x00;low_val = send_data&0x00ff; high_val = (send_data>>8)&0x00ff;//写开始时序/* wait until i2c bus is idle */while(i2c_flag_get(I2C1, I2C_FLAG_I2CBSY));/* send a start condition to I2C bus */i2c_start_on_bus(I2C1);/* wait until SBSEND bit is set */while(!i2c_flag_get(I2C1, I2C_FLAG_SBSEND)); /* send slave address to I2C bus *///写从机地址时序i2c_master_addressing(I2C1, I2C1_SLAVE_ADDRESS7, I2C_TRANSMITTER);/* wait until ADDSEND bit is set */while(!i2c_flag_get(I2C1, I2C_FLAG_ADDSEND));/* clear ADDSEND bit */i2c_flag_clear(I2C1, I2C_FLAG_ADDSEND);/* wait until the transmit data buffer is empty */while(!i2c_flag_get(I2C1, I2C_FLAG_TBE));//写寄存器地址时序i2c_data_transmit(I2C1, reg_addr);/* wait until the TBE bit is set */while(!i2c_flag_get(I2C1, I2C_FLAG_BTC));//写 写入数据 时序/* data transmission */i2c_data_transmit(I2C1, high_val);//先发送高8位数据/* wait until the TBE bit is set */while(!i2c_flag_get(I2C1, I2C_FLAG_BTC));i2c_data_transmit(I2C1, low_val);//再发送低8位数据/* wait until the TBE bit is set */while(!i2c_flag_get(I2C1, I2C_FLAG_BTC));//写停止时序 /* send a stop condition to I2C bus */i2c_stop_on_bus(I2C1);/* wait until stop condition generate */ while(I2C_CTL0(I2C1)&0x0200);
}/* I2C读函数 */
uint16_t i2c_read_byte(uint8_t reg_addr)
{uint8_t high_val=0x00;uint8_t low_val=0x00;uint16_t recv_val = 0x0000;//写开始时序/* wait until i2c bus is idle */while(i2c_flag_get(I2C1, I2C_FLAG_I2CBSY));/* send a start condition to I2C bus */i2c_start_on_bus(I2C1);/* wait until SBSEND bit is set */while(!i2c_flag_get(I2C1, I2C_FLAG_SBSEND)); //写 从机地址+写 时序/* send slave address to I2C bus */i2c_master_addressing(I2C1, I2C1_SLAVE_ADDRESS7, I2C_TRANSMITTER);/* wait until ADDSEND bit is set */while(!i2c_flag_get(I2C1, I2C_FLAG_ADDSEND));/* clear ADDSEND bit */i2c_flag_clear(I2C1, I2C_FLAG_ADDSEND);/* wait until the transmit data buffer is empty */while(!i2c_flag_get(I2C1, I2C_FLAG_TBE));//写 读寄存器地址 时序i2c_data_transmit(I2C1, reg_addr);/* wait until the BTC bit is set */while(!i2c_flag_get(I2C1, I2C_FLAG_BTC));//写停止时序i2c_stop_on_bus(I2C1);while(I2C_CTL0(I2C1)&0x0200);//写开始时序 i2c_start_on_bus(I2C1);/* wait until SBSEND bit is set */while(!i2c_flag_get(I2C1, I2C_FLAG_SBSEND));//写 从机地址+读 时序/* send slave address to I2C bus */i2c_master_addressing(I2C1, I2C1_SLAVE_ADDRESS7, I2C_RECEIVER);/* wait until ADDSEND bit is set */while(!i2c_flag_get(I2C1, I2C_FLAG_ADDSEND));/* clear the ADDSEND bit */i2c_flag_clear(I2C1,I2C_FLAG_ADDSEND);/* wait until the RBNE bit is set and clear it*/while(!i2c_flag_get(I2C1, I2C_FLAG_RBNE));//接收数据 时序high_val = i2c_data_receive(I2C1);while(!i2c_flag_get(I2C1, I2C_FLAG_RBNE));i2c_ack_config(I2C1, I2C_ACK_DISABLE);i2c_ackpos_config(I2C1,I2C_ACKPOS_NEXT);low_val = i2c_data_receive(I2C1);/* wait until the BTC bit is set *///while(!i2c_flag_get(I2C1, I2C_FLAG_BTC));代码卡死，屏蔽后不卡死，可以成功读取数据 //写停止时序/* send a stop condition to I2C bus */i2c_stop_on_bus(I2C1);/* wait until stop condition generate */ while(I2C_CTL0(I2C1)&0x0200);recv_val = (high_val<<8)|low_val;i2c_ack_config(I2C1, I2C_ACK_ENABLE);return recv_val;
}iic.h
#ifndef __IIC_H
#define __IIC_H#include "gd32f30x.h"
#include "string.h"void i2c_config(void);
void i2c_write(uint8_t reg_addr, uint16_t send_data);
uint16_t i2c_read_byte(uint8_t reg_addr);#endifmain.c
// 使能 RDY输出功能i2c_write(0x03,0x8000); // Write 0x8000 to Hi_Threshi2c_write(0x02,0x0000); // Write 0x0000 to Lo_Thresh// 配置ADC输入， 启动连续转换模式i2c_write(0x01,0xC4e0);//Write config, OS=1, AIN0 to GND, G=2(+/-2.048V input range),//continuous mode conversion, DR=800, others default //COMP_QUE = 00Vbat = i2c_read_byte(0x00);//读取电压值//转换 Vbat/65535*参考电压（比如4.096V)
