Example Code for Arduino-UART Mode (Serial Command)
Last revision 2025/12/18
This code tests the range finder function of the URM13 ultrasonic sensor
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
Sample Code
/**************************************************************************************************************
This code tests the range finder function of the URM13 ultrasonic sensor
@ author : [email protected]
@ data : 21.08.2020
@ version: 1.0
**************************************************************************************************************/
#define SLAVE_ADDR ((uint16_t)0x0D)
#define TEMP_CPT_SEL_BIT ((uint16_t)0x01 << 0)
#define TEMP_CPT_ENABLE_BIT ((uint16_t)0x01 << 1)
#define MEASURE_MODE_BIT ((uint16_t)0x01 << 2)
#define MEASURE_TRIG_BIT ((uint16_t)0x01 << 3)
#define MEASURE_RANGE_BIT ((uint16_t)0x01 << 4)
#define MB_OP_WRITE_SINGLE_HOLDING_REG ((uint8_t)0x06)
#define MB_OP_READ_HOLDING_REGS ((uint8_t)0x03)
typedef enum {
ePid,
eVid,
eAddr,
eComBaudrate,
eComParityStop,
eDistance,
eInternalTempreture,
eExternTempreture,
eControl,
eNoise,
eSensitivity
} eRegIndex_t; //Sensor register index
static const uint8_t aucCRCHi[] = {
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40
};
static const uint8_t aucCRCLo[] = {
0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06, 0x07, 0xC7,
0x05, 0xC5, 0xC4, 0x04, 0xCC, 0x0C, 0x0D, 0xCD, 0x0F, 0xCF, 0xCE, 0x0E,
0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09, 0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9,
0x1B, 0xDB, 0xDA, 0x1A, 0x1E, 0xDE, 0xDF, 0x1F, 0xDD, 0x1D, 0x1C, 0xDC,
0x14, 0xD4, 0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3,
0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3, 0xF2, 0x32,
0x36, 0xF6, 0xF7, 0x37, 0xF5, 0x35, 0x34, 0xF4, 0x3C, 0xFC, 0xFD, 0x3D,
0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A, 0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38,
0x28, 0xE8, 0xE9, 0x29, 0xEB, 0x2B, 0x2A, 0xEA, 0xEE, 0x2E, 0x2F, 0xEF,
0x2D, 0xED, 0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26,
0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60, 0x61, 0xA1,
0x63, 0xA3, 0xA2, 0x62, 0x66, 0xA6, 0xA7, 0x67, 0xA5, 0x65, 0x64, 0xA4,
0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F, 0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB,
0x69, 0xA9, 0xA8, 0x68, 0x78, 0xB8, 0xB9, 0x79, 0xBB, 0x7B, 0x7A, 0xBA,
0xBE, 0x7E, 0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5,
0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71, 0x70, 0xB0,
0x50, 0x90, 0x91, 0x51, 0x93, 0x53, 0x52, 0x92, 0x96, 0x56, 0x57, 0x97,
0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C, 0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E,
0x5A, 0x9A, 0x9B, 0x5B, 0x99, 0x59, 0x58, 0x98, 0x88, 0x48, 0x49, 0x89,
0x4B, 0x8B, 0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C,
0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42, 0x43, 0x83,
0x41, 0x81, 0x80, 0x40
};
static uint16_t mbCrcCalculated(uint8_t * pCmd, uint8_t usLen )
{
uint8_t ucCRCHi = 0xFF;
uint8_t ucCRCLo = 0xFF;
int16_t iIndex;
while ( usLen-- )
{
iIndex = ucCRCLo ^ *( pCmd++ );
ucCRCLo = ( uint8_t )( ucCRCHi ^ aucCRCHi[iIndex] );
ucCRCHi = aucCRCLo[iIndex];
}
return ( uint16_t )( (uint16_t)ucCRCHi << 8 | ucCRCLo );
}
/*
@brief Read data from holding register of client
@param addr ： Address of Client
@param reg: Reg index
@param regNum: The number of registers to read，The register is 16 bits wide
@param pBuf:Points to the receive data buffer
*/
void readHoldingRegisters(uint16_t addr, eRegIndex_t regIndex, uint16_t regNum, uint8_t *pBuf)
{
uint8_t pCmdBuf[8], i;
uint16_t crc;
pCmdBuf[0] = addr;
pCmdBuf[1] = MB_OP_READ_HOLDING_REGS;
pCmdBuf[2] = regIndex >> 8;
pCmdBuf[3] = (uint8_t)regIndex;
pCmdBuf[4] = regNum >> 8;
pCmdBuf[5] = (uint8_t)regNum;
crc = mbCrcCalculated(pCmdBuf, 6);
pCmdBuf[6] = (uint8_t)crc;
pCmdBuf[7] = crc >> 8;
for (i = 0; i < 8; i++) {
Serial1.write( pCmdBuf[i]);
}
delay(150);
i = 0;
while (Serial1.available()) {
pBuf[i++] = (Serial1.read());
}
}
/*
@brief Write data to holding register of client
@param addr ： Address of Client
@param reg: Reg index
@param data: The data to be sent
@param pBuf:Points to the receive data buffer
*/
void writeSigleHoldingRegister(uint16_t addr, eRegIndex_t regIndex, uint16_t data, uint8_t *pBuf)
{
uint8_t pCmdBuf[8], i;
uint16_t crc;
pCmdBuf[0] = addr;
pCmdBuf[1] = MB_OP_WRITE_SINGLE_HOLDING_REG;
pCmdBuf[2] = regIndex >> 8;
pCmdBuf[3] = (uint8_t)regIndex;
pCmdBuf[4] = data >> 8;
pCmdBuf[5] = (uint8_t)data;
crc = mbCrcCalculated(pCmdBuf, 6);
pCmdBuf[6] = (uint8_t)crc;
pCmdBuf[7] = crc >> 8;
for (i = 0; i < 8; i++) {
Serial1.write( pCmdBuf[i]);
}
delay(150);
i = 0;
while (Serial1.available()) {
pBuf[i++] = (Serial1.read());
}
}
uint8_t rxBuf[100];
int16_t dist; float temp;
volatile uint16_t cr = 0;
void setup() {
Serial1.begin(19200);
Serial.begin(9600);
cr &= ~TEMP_CPT_SEL_BIT;//clear bit0, select internal temperature compensation
//cr |= TEMP_CPT_SEL_BIT;//set bit0,select external temperature compensation
cr &= ~TEMP_CPT_ENABLE_BIT;//clear bit1,enable temperature compensation
//cr |= TEMP_CPT_ENABLE_BIT; //set bit1,disable temperature compensation
cr |= MEASURE_MODE_BIT;//set bit2 , set to trigger mode
//cr &= ~MEASURE_MODE_BIT;//clear bit2 , set to Automatic ranging mode
cr &= ~MEASURE_RANGE_BIT;//clear bit4,long-range ranging mode
//cr |= MEASURE_RANGE_BIT; //set bit4,short-range ranging mode
writeSigleHoldingRegister(SLAVE_ADDR, eControl, cr, rxBuf); //Writes the setting value to the control register
delay(100);
}
void loop() {
cr |= MEASURE_TRIG_BIT;//Set trig bit
writeSigleHoldingRegister(SLAVE_ADDR, eControl, cr, rxBuf); //Write the value to the control register and trigger a ranging
delay(300);//Delay of 300ms(minimum delay should be greater than 100ms) is to wait for the completion of ranging
readHoldingRegisters(SLAVE_ADDR, eDistance, 1, rxBuf); //Read distance register, one LSB is 1cm
dist = (int16_t)rxBuf[3] << 8 | rxBuf[4];
delay(10);
readHoldingRegisters(SLAVE_ADDR, eInternalTempreture, 1, rxBuf); //Read tempreture register
temp = (float)((int16_t)rxBuf[3] << 8 | rxBuf[4]) / 10.0;// one LSB is 0.1 ℃
Serial.print("dist = ");
Serial.print(dist);
Serial.print("cm---");
Serial.print("temp = ");
Serial.print(temp);
Serial.println(" ℃");
}
Result
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