SEN0002

  URM04 V2.0 (SKU:SEN0002) URM04 V2.0 Figure 1: URM04 Beam Width 60 degree Contents 1 Introduction 2 Specification 3 Dimension and Pin definition 4 Communication Protocols 4.1 Set Device Address 4.2 Trigger measurement 4.3 Read Distance 4.4 Read tempeature 5 Sensor Connection Diagram 6 Sensor Networking 7 Arduino sketch for driving one URM04 sensor Introduction A. Please read this mannual carefully before power on the device. B. Do not use this device for military or medical purpose as they are not designed to. URM04 is developed based upon our popular URM37 ultrasonic sensor. The RS485 interface allows a number of sensors working together. Up to 32 URM04 may be connected together in a network. Specification Power: +5V Current: =0xF0) { Temperature= ((HightByte-0xF0)*256-LowByte)/10 } Else { Temperature= ((HightByte)*256-LowByte)/10 } Sensor Connection Diagram As the sensor uses RS485 interface which can not be connected directly to the MCU, a MAX485 chip will bridge the TTL interface to RS485, as shown in Figure 4. For PC users, either a USB-RS485 or RS232-RS485 converter will bridge the gap. A diagram is depicted in Figure 5 and 6. Figure 4 Connect Sensor to MCU via MAX485 Figure 5 Connect Sensor to PC via USB-RS485 converter Figure 6 Connect Sensor to PC via RS232-RS485 Converter Figure 7 Connect Sensor to Arduino Via MAX485 IC  Sensor Networking Upto 32 URM04 sensors are able to join a network. Simply serially connect the sensors uses twisted pair cables. A diagram is illustrated in Figure 7. Figure 7 URM04 Networking Arduino sketch for driving one URM04 sensor The sketch code: /* # The Sample code for driving single URM04 measuring distance function # Editor : Lauren # Date : 2012.2.8 # Ver : 0.3 # Product: URM04 Ultrasonic sensor # Specification * Detecting range: 4cm-500cm * Resolution : 1cm * Interface : RS485 * Units: Range reported in cm * Temperature sensor: 12 bits reading from serial port # Description: # finish driving single URM function # if use the IO expansion shield to drive the urm sensors, the measuring rate may be 20Hz or slower[if you want]. # The sample code is compatible with the Arduino IDE 1.0 and also the earlier version. */ #include "Urm4parser.h" void setup(){ urmInit(); // Init the URM04 sensor } void loop(){ static unsigned long timePoint = 0; runUrm4(); // Drive URM04 Sensor and transmit the protocol to the sens or via RS485 interface // (IO Expansion shield V5 for arduino) decodeURM4(); // Read and get the distance value from the sensor if(millis() - timePoint > 100){ PrintData(); // print the data timePoint = millis(); } // PrintData(); // delay(100); } void PrintData(){ Serial.print("Distance value: "); for(int i = 0; i < urmAccount; i++){ Serial.print(urmData[i]); Serial.print(" "); } /* for(int i = 0; i < urmAccount;i ++){ Serial.print(urmID[i],HEX); Serial.print(" "); } */ Serial.println(); } The library code: please place the library file Urm4parser.h in to the sketch folder. /* # The library for the URM04 sketch # Editor : Lauren # Date : 2012.2.8 # Ver : 0.3 # Product: URM04 Ultrasonic sensor # Specification * Detecting range: 4cm-500cm * Resolution : 1cm * Interface : RS485 * Units: Range reported in cm * Temperature sensor: 12 bits reading from serial port # Description: # finish driving single URM function # if use the IO expansion shield to drive the urm sensors, the measuring rate may be 20Hz or slower[if you want]. # The sample code is compatible with the Arduino IDE 1.0 and also the earlier version. */ #if defined(ARDUINO) && ARDUINO >= 100 #include "Arduino.h" #define printByte(args) Serial.write(args) #else #include "WProgram.h" #define printByte(args) Serial.print(args,BYTE) #endif #define SerialPort Serial #define urmAccount 1 // Init the account of the URM04 sensor #define CommMAXRetry 40 #define TriggerPin 2 /******************** Variables ****************/ byte startAddr = 0x11; // Init the URM04 485 Address -- URM04 default address = 0x11 byte readingStep; byte cmdst[10]; int urmID[urmAccount]; unsigned int urmData[urmAccount]; unsigned long managerTimer = 20; /******************** Functions ****************/ void urmInit(); void runUrm4(); void urmTrigger(int id); void urmReader(int id); void transmitCommands(); void decodeURM4(); void analyzeUrmData(byte cmd[]); /****************** Init sensor ****************/ void urmInit(){ pinMode(TriggerPin,OUTPUT); // TTL -> RS485 chip driver pin digitalWrite(TriggerPin,LOW);// Turn the driver pin to LOW ing mode for the RS485 interface -> Turn on read // Turn the drvier pin to HIGH -> Turn on code transmitting mode for the RS485 interface readingStep = 0; startAddr = 0x11; managerTimer = millis(); for(int i = 0 ;i < urmAccount; i ++){ ddress //Init the URM04 command receiving a urmID[i] = startAddr + i; urmData[i] = 0; } SerialPort.begin(19200); // Init the RS485 interface // Also when you are driving the URM 04, you could open serial monitor to // tracing the steps and data feedba ck from URM04 SerialPort.println(); SerialPort.print("The URM ID: 0x"); for(int i = 0 ;i < urmAccount; i ++){ ddress //Init the URM04 command receiving a SerialPort.print(urmID[i],HEX); SerialPort.print(" "); } SerialPort.println(" "); SerialPort.println("The default baudrate: 19200"); SerialPort.println("Start drive the sensors!"); for(int i = 0 ;i < 10; i++) cmdst[i] = 0; //init the URM04 protocol cmdst[0]=0x55; cmdst[1]=0xaa; } /********************* Drive URM04 and get the data code ******************** *****/ void runUrm4(){ // You could adjust the sensor measuring rate by changing the managerTimer value static unsigned long timer = 0; static int num = 0; //Set the URM04 id to be drived if(millis() - timer > managerTimer){ digitalWrite(TriggerPin, HIGH); 5 interface //Turn on transmitting mode for the RS48 switch(readingStep){ case 0: urmTrigger(urmID[num]); managerTimer = 40; //set a interval after trigger the measur ing break; case 1: urmReader(urmID[num]); managerTimer = 0; eading distance command break; case 2: //set a interval after transmitting the r digitalWrite(TriggerPin, LOW); //Turn on reading mode for the RS485 int erface managerTimer = 10; break; default: readingStep = 0; a new measuring for the sensor // Finish reading the distance and start break; } if(readingStep < 2) readingStep++; //step manager else readingStep = 0; timer = millis(); } } /********************* Transmit Command via the RS485 interface ************* **/ void urmTrigger(int id){ // The function is used to trigger the measuring cmdst[2] = id; cmdst[3] = 0x00; cmdst[4] = 0x01; transmitCommands(); // SerialPort.println("Trigger!"); } void urmReader(int id){ // The function is used to read the distance cmdst[2] = id; cmdst[3]=0x00; cmdst[4]=0x02; transmitCommands(); // SerialPort.println("Ask for distance!"); } void transmitCommands(){ // Send protocol via RS485 interface cmdst[5]=cmdst[0]+cmdst[1]+cmdst[2]+cmdst[3]+cmdst[4]; delay(1); for(int j = 0; j < 6; j++){ printByte(cmdst[j]); // delayMicroseconds(10); } delay(2); } /********************* Receive the data and get the distance value from the R S485 interface ***************/ void decodeURM4(){ if(SerialPort.available()){ unsigned long timerPoint = millis(); int RetryCounter = 0; byte cmdrd[10]; for(int i = 0 ;i < 10; i++) cmdrd[i] = 0; int i=0; // SerialPort.println("OK"); boolean flag = true; boolean valid = false; byte headerNo = 0; while(RetryCounter < CommMAXRetry && flag) { if(SerialPort.available()){ cmdrd[i]= SerialPort.read(); // printByte(cmdrd[i]); if(i > 7){ flag=false; // printByte(0xEE); // printByte(0xFF); SerialPort.flush(); break; } if(cmdrd[i] == 0xAA){ headerNo = i; valid = true; } if(valid && i == headerNo + 6){ // printByte(0xDD); // printByte(0xFF); flag = false; break; } i ++; RetryCounter = 0; } else{ RetryCounter++; delayMicroseconds(15); } } // printByte(millis() - timerPoint); if(valid) analyzeUrmData(cmdrd); // else SerialPort.println("Invalid feedback"); mmand //Get an invalid error co } } void analyzeUrmData(byte cmd[]){ byte sumCheck = 0; for(int h = 0;h < 7; h ++) sumCheck += cmd[h]; if(sumCheck == cmd[7] && cmd[3] == 2 && cmd[4] == 2){ byte id = cmd[2] - startAddr; urmData[id] = cmd[5] * 256 + cmd[6]; // SerialPort.print(id); // SerialPort.print(":"); // SerialPort.println(urmData[id]); } else if(cmd[3] == 2 && cmd[4] == 2){ SerialPort.print("Sum error"); } } Powered By DFRobot © 2008-2017