从具有相同地址的i2c传感器读取值

Question

我有4个SingleTact电容式传感器,每个传感器的i2c地址为0x04.我想找到传感器的平均值,以制作操纵杆.但是我不确定如何为每个传感器分配它自己的地址,因为它们都具有相同的地址,因为它们是相同的传感器.我有一个初始代码,但这只适用于一个传感器,因为它只有一个i2c地址字节.我已经使用在线教程将所有SDA和SCL线连接在一起,并包含了上拉电阻.

#include <Wire.h>
#define initializetime 4
byte serialToPCBuffer[77];
byte serialToPCBufferIndex = 0;

int data[4];
int databuffer[4][initializetime] = {0,0,0,0,0,0,0,0,0,0,0,0};
int base[4] = {0,0,0,0};
int ArduinoToPCBuffer[4] = {1000,2000,3000,4000};
byte outgoingI2CBuffer[32];
unsigned long timeStamp_;

void setup() {
  int i;
  Wire.begin();
  //TWBR = 12;
  Serial.begin(57600);
  Serial.flush();
  initializeSensors();

  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }
  Serial.println("PPS UK: SingleTact sensor value in PSI. \n(resembles PC executable display)");
  Serial.println("Refer manual for any other calculation.");
  Serial.println("----------------------------------------");  
}    

void loop(){
  byte i2cAddress = 0x04; // Slave address (SingleTact), default 0x04
  int data = readDataFromSensor(i2cAddress);
  Serial.print("I2C Sensor Data:");
  Serial.print(data);    
  Serial.print("\n");
  delay(100); // Change this if you are getting values too quickly 
}

int readDataFromSensor(int address)
{
  byte i = 0;
  byte i2cPacketLength = 6;
  byte outgoingI2CBuffer[3];
  byte incomingI2CBuffer[6];

  outgoingI2CBuffer[0] = 0x01;
  outgoingI2CBuffer[1] = 128;
  outgoingI2CBuffer[2] = i2cPacketLength;

  Wire.beginTransmission(address);
  Wire.write(outgoingI2CBuffer,3);
  byte error = Wire.endTransmission();
  if (error != 0) return -1;
  Wire.requestFrom(address,i2cPacketLength);

  int incomeCount =0;
  while(incomeCount < i2cPacketLength)
  {
    if(Wire.available())
    {
    incomingI2CBuffer[incomeCount] = Wire.read();
    incomeCount++;
    }
    else
    {
    delay(1);
    }
  }
  if(serialToPCBuffer[4] == 0x00 && serialToPCBuffer[5] == 0xFE)
  {
    serialToPCBuffer[5] = 0xFF;
  }

  int datafromi2c = serialToPCBuffer[4]*256+serialToPCBuffer[5]-base[address-5];

  if(datafromi2c<21)
    datafromi2c = 0;

  return datafromi2c;
}

void initializeSensors()
{
  for(int k = 0;k<4;k++)
  {
    databuffer[k][0] = readDataFromSensor(k+5);
    delay(10);
    databuffer[k][1] = readDataFromSensor(k+5);
    delay(10);
    databuffer[k][2] = readDataFromSensor(k+5);
    delay(10);
    databuffer[k][3] = readDataFromSensor(k+5);
    delay(10);
    base[k] = (databuffer[k][0] + databuffer[k][1] + databuffer[k][2] +     databuffer[k][3])/3;
  }
}

谢谢你的建议.

Answer 1

您应该阅读此设备的手册,可在此处获得.它在界面描述中说

多个传感器接口可以连接到单个I2C总线.可以通过I2C接口写入所需的地址值(4到127)来配置各个传感器接口的总线地址,以通过I2C写操作注册地址0.PC和Arduino示例支持更改单个传感器I2C地址.

所以你必须这样做

1. 插上第一个传感器
2. 将地址(例如0x41)写入该器件的寄存器0
3. 拔下传感器
4. 对于使用不同地址的所有传感器,重复1-2-3

然后每个传感器将回复您设置的地址.

请注意

由于接口板将始终响应地址0x04,因此必须将此地址视为为SingleTact保留.如果要将多个SingleTact接口连接到同一I2C总线,则必须将地址0x04视为无效

所以,即使在这种情况下,RTFM建议也是最重要的建议......