使用Arduino驱动 ADS1115 ADC采样芯片
如图，这是这颗ADC采样芯片的内部结构图，能够看到， 从芯片引脚到芯片内部的ADC模块，还有几个部分： MUX，PGA， 这两个分别叫作多路复用器、和增益放大器， MUX用来切换采样引脚，而PGA则用来切换测量量程。oop
我参照芯片官方的数据手册写出了这个简易的测试程序，只用到了最基本的IIC的通信， 使用功能也比较有限，高级一些的功能都须要使用基于IIC通信的SMBUS协议， 这个就没有继续深究了。测试
#include <Wire.h>
const int8_t ADS1115_address = 0x48;
enum ADS1115Conf{
AIN0_2AIN1 = 0b000, // << 12,
AIN0_2AIN3 = 0b001, // << 12,
AIN1_2AIN3 = 0b010, // << 12,
AIN2_2AIN3 = 0b011, // << 12,
AIN0_2GND = 0b100, // << 12,
AIN1_2GND = 0b101, // << 12,
AIN2_2GND = 0b110, // << 12,
AIN3_2GND = 0b111, // << 12,
FSR_6_144V = 0b000, // << 9,
FSR_4_096V = 0b001, // << 9,
FSR_2_048V = 0b010, // << 9,
FSR_1_024V = 0b011, // << 9,
FSR_0_512V = 0b100, // << 9,
FSR_0_256V = 0b101, // << 9,
CONTINU_CONV = 0, //<<8
SINGLE_SHOT = 1,
SPS_8 = 0b000, // << 5,
SPS_16 = 0b001, // << 5,
SPS_32 = 0b010, // << 5,
SPS_64 = 0b011, // << 5,
SPS_128 = 0b100, // << 5,
SPS_250 = 0b101, // << 5,
SPS_475 = 0b110, // << 5,
SPS_860 = 0b111, // << 5,
}typedef ADS1115Conf;
/**
* [ADS1115Configure description]
* @Author 叶鹏程
* @DateTime 2019-08-19T20:44:30+0800
* @discrption : 芯片初始化配置
*
* @param mux [输入通道配置]
* @param pga [量程设置]
* @param mode [单次或持续转换模式]
* @param dr [采样速率设置]
*/
void ADS1115Configure(ADS1115Conf mux, ADS1115Conf pga, ADS1115Conf mode, ADS1115Conf dr){
uint16_t conf;
Wire.beginTransmission(ADS1115_address);
Wire.write(0x01); //set Address Pointer Register as conf Register
Wire.endTransmission();
/*read chip's conf register data */
Wire.requestFrom(ADS1115_address, 2);
conf = 0;
conf = Wire.read();
conf = conf<<8;
conf |= Wire.read();
/*change it*/
conf = 0x8000;
conf &= (~(0x0007<< 12)); conf |= mux << 12;
conf &= (~(0x0007<< 9 )); conf |= pga << 9;
conf &= (~(0x0007<< 8 )); conf |= mode << 8;
conf &= (~(0x0007<< 5 )); conf |= dr << 5;
// conf = 0xf483;
/* trans back*/
Wire.beginTransmission(ADS1115_address);
Wire.write(0x01); //set Address Pointer Register as conf Register
Wire.write(uint8_t(conf>>8)); //conf MSB
Wire.write(uint8_t(conf)); //conf LSB
Wire.endTransmission();
/**/
Wire.beginTransmission(ADS1115_address);
Wire.write(0x00); //set Address Pointer Register as conf Register
Wire.endTransmission();
}
/**
* [ADS1115SetChannel description]
* @Author 叶鹏程
* @DateTime 2019-08-19T20:43:57+0800
* @discrption :芯片输入通道设置
*
* @param mux [description]
*/
void ADS1115SetChannel(ADS1115Conf mux){
uint16_t conf;
Wire.beginTransmission(ADS1115_address);
Wire.write(0x01); //set Address Pointer Register as conf Register
Wire.endTransmission();
/*read chip's conf register data */
Wire.requestFrom(ADS1115_address, 2);
conf = 0;
conf = Wire.read();
conf = conf<<8;
conf |= Wire.read();
/*change it*/
conf = conf & (~(0x0007<< 12)); conf |= mux << 12;
/* trans back*/
Wire.beginTransmission(ADS1115_address);
Wire.write(0x01); //set Address Pointer Register as conf Register
Wire.write(uint8_t(conf>>8)); //conf MSB
Wire.write(uint8_t(conf)); //conf LSB
Wire.endTransmission();
/**/
Wire.beginTransmission(ADS1115_address);
Wire.write(0x00); //set Address Pointer Register as conf Register
Wire.endTransmission();
}
int16_t ADS1115ReadResult(void){
int16_t ret;
Wire.requestFrom(ADS1115_address, 2);
ret = 0;
ret = Wire.read();
ret = ret<<8;
ret |= Wire.read();
return ret;
}
void setup() {
// put your setup code here, to run once:
Wire.begin();
Serial.begin(115200);
while (!Serial); // Leonardo: wait for serial monitor
Serial.println("Arduino Running!");
Serial.println("configing ADS1115.");
delay(200);
ADS1115Configure(AIN3_2GND, FSR_6_144V, CONTINU_CONV, SPS_250);
Serial.println("configed.");
Wire.beginTransmission(ADS1115_address);
Wire.write(0x00); //set Address Pointer Register as conv Register
Wire.write(0x00);
Wire.write(0x00);
Wire.endTransmission();
}
void loop() {
int16_t adc_result;
double v;
Serial.print("adc conversion result: ");
ADS1115SetChannel(AIN0_2GND);
delay(10);
adc_result = ADS1115ReadResult(); v = adc_result * 6.144 / 0x7fff;
Serial.print("\tA0: "); Serial.print(v); Serial.print('V');
ADS1115SetChannel(AIN1_2GND);
delay(10);
adc_result = ADS1115ReadResult(); v = adc_result * 6.144 / 0x7fff;
Serial.print("\tA1: "); Serial.print(v); Serial.print('V');
ADS1115SetChannel(AIN2_2GND);
delay(10);
adc_result = ADS1115ReadResult(); v = adc_result * 6.144 / 0x7fff;
Serial.print("\tA2: "); Serial.print(v); Serial.print('V');
ADS1115SetChannel(AIN3_2GND);
delay(10);
adc_result = ADS1115ReadResult(); v = adc_result * 6.144 / 0x7fff;
Serial.print("\tA3: "); Serial.print(v); Serial.print('V');
Serial.println();
delay(100);
// put your main code here, to run repeatedly:
}