Example Code for Arduino-I2C Mode

Hardware Preparation

• Name: Arduino Leonardo, Model/SKU: , Quantity: 1, Purchase Link: https://www.dfrobot.com/product-832.html
• Name: USB Data Cable, Model/SKU: , Quantity: 1, Purchase Link:

Software Preparation

• Development tools: Arduino IDE

Wiring Diagram

Other Preparation Work

Switch the sensor to I2C mode by short-circuiting pin TRIG and ECHO before powering on.

Sample Code

/*!
       Download this demo to test config to URM13, connect sensor through IIC interface
       Data will print on your serial monitor

       This example is the ultrasonic passive measurement distance and the temperature of the module.

       Copyright   [DFRobot](http://www.dfrobot.com), 2018
       Copyright   GNU Lesser General Public License

       version  V1.0
       date  21/08/2020
*/
#include <Wire.h>
typedef enum {
  eAddr = 0,
  ePid,
  eVid,
  eDistanceH ,
  eDistanceL,
  eInternalTempretureH,
  eInternalTempretureL,
  eExternalTempretureH,
  eExternalTempretureL,
  eConfig,
  eCmd,
  eNoise,
  eSensitivity,
  eRegNum
} regindexTypedef;

#define    MEASURE_RANGE_BIT        ((uint8_t)0x01 << 4)
#define    MEASURE_MODE_BIT         ((uint8_t)0x01 << 2)
#define    TEMP_CPT_ENABLE_BIT      ((uint8_t)0x01 << 1)
#define    TEMP_CPT_SEL_BIT         ((uint8_t)0x01 << 0)

#define    IIC_SLAVE_ADDR           ((uint8_t)0x12)
#define    isSensorBusy()           (digitalRead(busyPin))

int16_t    busyPin = 4;
/*
  @brief Write data to register of client

  @param addr ： Address of Client
  @param regIndex: Reg index
  @param pDataBuf: point to data buffer
  @param dataLen: data length
*/
void i2cWriteBytes(uint8_t addr, regindexTypedef regIndex , uint8_t *pDataBuf, uint8_t dataLen )
{
  Wire.beginTransmission(addr); // transmit to device
  Wire.write(regIndex);              // sends one byte
  for (uint8_t i = 0; i < dataLen; i++) {
    Wire.write(*pDataBuf);
    pDataBuf++;
  }
  Wire.endTransmission();    // stop transmitting
}
/*
  @brief Read data from register of client

  @param addr ： Address of Client
  @param regIndex: Reg index
  @param pDataBuf: point to data buffer
  @param dataLen: data length
*/
void i2cReadBytes(uint8_t addr, regindexTypedef regIndex , uint8_t *pDataBuf, uint8_t dataLen )
{
  unsigned char i = 0;
  Wire.beginTransmission(addr); // transmit to device #8
  Wire.write(regIndex);              // sends one byte
  Wire.endTransmission();    // stop transmitting
  Wire.requestFrom(addr, dataLen);
  while (Wire.available()) {  // slave may send less than requested
    pDataBuf[i] = Wire.read();
    i++;
  }
}

uint8_t cfg = 0, cmd = 0;
uint8_t rxBuf[100] = {0};
void setup() {
  Wire.begin(); // join i2c bus (address optional for master)
  Serial.begin(9600); // join i2c bus (address optional for master)
  pinMode(busyPin, INPUT);
  cfg &= ~MEASURE_RANGE_BIT;//clear bit4,long-range ranging mode
  //cfg |= MEASURE_RANGE_BIT;//set bit4,short-range ranging mode
  cfg |=  MEASURE_MODE_BIT;//Set bit2，i2c passive mode
  //cfg &= ~MEASURE_MODE_BIT;//clear bit2 , set to Automatic ranging mode
  cfg &= ~TEMP_CPT_ENABLE_BIT;//clear bit1,enable temperature compensation
  //cfg |= TEMP_CPT_ENABLE_BIT;//set bit1,disable temperature compensation
  cfg &= ~TEMP_CPT_SEL_BIT;//clear bit0,select internal temperature compensation
  //cfg |= TEMP_CPT_SEL_BIT;//set bit0,select external temperature compensation
  i2cWriteBytes(IIC_SLAVE_ADDR, eConfig , &cfg, 1 );
  delay(100);
}
void loop() {
  int16_t  dist, temp;
  cmd |= 0x01;//Set trig bit
  i2cWriteBytes(IIC_SLAVE_ADDR, eCmd , &cmd, 1 );//Write command register
  //You can replace the delay with these two lines of code
  //while(isSensorBusy()== HIGH);  //Wait for the sensor to start ranging
  //while(isSensorBusy()== LOW);   //Wait for sensor ranging to complete
  delay(100);//delay 100ms
  i2cReadBytes(IIC_SLAVE_ADDR, eDistanceH, rxBuf, 2 ); //Read distance register
  dist = ((uint16_t)rxBuf[0] << 8) + rxBuf[1];
  delay(10);
  i2cReadBytes(IIC_SLAVE_ADDR, eInternalTempretureH, rxBuf, 2 ); //Read the onboard temperature register
  temp = ((uint16_t)rxBuf[0] << 8) + rxBuf[1];

  Serial.print(dist, DEC);
  Serial.print("cm");
  Serial.print("------");

  Serial.print((float)temp / 10, 1);
  Serial.println("℃");
}

Result