VL53L0X Multiple Sensors, Adjust IC2 address

GarrettC · February 27, 2019, 3:47pm

Hey. So I am trying to assemble a robot car that avoids hitting walls. To do this I am planning to use the VL53L0X sensor. The difficulty is using the two sensors.

For a little while I had it almost working however the values were not actual readings. Currently however the code is not getting past the sensor1.init(true) line.

Any suggestions would be appreciated. One other consideration is that I am using a custom shield so I don’t have the ability to use the XSHUT pin.

#include<Wire.h>
#include <math.h>
#include <MPU6050_tockn.h>
#include <VL53L0X.h>


//MPU-6050
MPU6050 mpu6050(Wire);


//VL53L0X
VL53L0X sensor1;
VL53L0X sensor2;

//IR
int IR_1 = 5;
int IR_2 = 6;
int IR_3 = 8;
int IR_4 = 9;


//A4988
int Step_A = 11;
int Dir_A = 10;
int Step_B = 3;
int Dir_B = 2;

int value = 0; 
int Index;
char Selection;
int SensorValue;

void setup() 
{

  //Serial
  Serial.begin(9600);

  
  //MPU-6050
  Wire.begin();
  mpu6050.begin();

  //VL53L0X
  Serial.println("S1 start");

  sensor1.init(true);

  Serial.println("01");
  delay(100);
  sensor1.setAddress((uint8_t)22);
  Serial.println("02");

  delay(150);

  Serial.println("S2 start");
  sensor2.init(true);
  Serial.println("03");
  delay(100);
  sensor2.setAddress((uint8_t)25);
  Serial.println("04");

  Serial.println("addresses set");

  sensor1.setTimeout(500);
  sensor1.startContinuous();

  sensor2.setTimeout(500);
  sensor2.startContinuous();

  //IR
  pinMode(IR_1, INPUT); 
  pinMode(IR_2, INPUT); 
  pinMode(IR_3, INPUT); 
  pinMode(IR_4, INPUT); 
  

  //STEPPER MOTORS
  pinMode(Step_A, OUTPUT); 
  pinMode(Dir_A, OUTPUT); 
  pinMode(Step_B, OUTPUT);
  pinMode(Dir_B, OUTPUT); 

  shortMenu();
}

void loop() 
{
  if (Serial.available()){
    Selection = Serial.read();
  
    switch (Selection)
    {
      case '1':
      {
        Serial.println(F("************* TESTING STEPPERS MOTORS - A4988 ******************"));
        testSteppers();
        break;
      }
            case '2':
      {
        Serial.println(F("******************* MESURING VOLTAGE INPUT *********************"));
        mesureVoltage();
        break;
      }
           case '3':
      {
        Serial.println(F("*************** TESTING GYROSCOPE - MPU6050 ********************"));
        displayGyro();
        break;
      }
           case '4':
      {
        Serial.println(F("**************** MESURING DISTANCE - VL53L0X *******************"));
        displayVL53L0X();
        break;
      }
           case '5':
      {
        Serial.println(F("******************* TESTING IR LIMITERS ************************"));
        displayIR();
        break;
      }
    }
  }
}

//********************** TEST STEPPERS MOTORS **********************
void testSteppers() {
  Serial.println(F("MOT_A: RIGHT"));
  turnRight(Dir_A, Step_A, 100);
  delay(1000);
  Serial.println(F("MOT_B: RIGHT"));
  turnRight(Dir_B, Step_B, 100);
  delay(1000);
  Serial.println(F("MOT_A: LEFT"));
  turnLeft(Dir_A, Step_A, 100);
  delay(1000);
  Serial.println(F("MOT_B: LEFT"));
  turnLeft(Dir_B, Step_B, 100);
  delay(1000);
  Serial.println(F("MOT_A & MOT_B: RIGHT"));
  turnRight(Dir_A, Step_A, 100);
  turnRight(Dir_B, Step_B, 100);
  delay(1000);
  Serial.println(F("MOT_A & MOT_B: LEFT"));
  turnLeft(Dir_A, Step_A, 100);
  turnLeft(Dir_B, Step_B, 100);
  shortMenu();
}

void turnRight(int Mot_Dir, int Mot_Step, int spd) {
  digitalWrite( Mot_Dir,HIGH);
  for (int i =0; i <= 3000; i++){
    digitalWrite(Mot_Step, HIGH);
    delayMicroseconds(spd);
    digitalWrite(Mot_Step, LOW);
  }
}

void turnLeft(int Mot_Dir, int Mot_Step, int spd) {
  digitalWrite( Mot_Dir,LOW);
  for (int i =0; i <= 3000; i++){
    digitalWrite(Mot_Step, HIGH);
    delayMicroseconds(spd);
    digitalWrite(Mot_Step, LOW);
  }
}

void turnMotors(int Mot_Dir_A, int Mot_Step_A, bool dir_A, bool turn_A, int Mot_Dir_B, int Mot_Step_B, bool dir_B, bool turn_B, int spd) {
  if (turn_A == true && turn_B == true){
    //TURN BOTH
    if (dir_A == true && dir_B == true){
      //TURN A and B RIGHT
    } else if( dir_A == true && dir_B == false) {
      //TURN A RIGHT and B LEFT
    } else if ( dir_A == false && dir_B == true) {
      //TURN A LEFT and B RIGH
    } else {
      //TURN A LEFT and B LEFT
    }
  } else if (turn_A == true && turn_B == false) {
    //TURN A ONLY
    if (dir_A == true) {
      //TURN A RIGHT
    } else {
      //TURN A LEFT 
    }
  } else if (turn_A == false && turn_B == true) {
    //TURN B ONLY
    if (dir_B == true){
      //TURN B RIGHT
    } else {
      //TURN B LEFT
    }
  }  
}




//********************** BATTERY VOLTAGE **********************

void mesureVoltage() {
  SensorValue = .0;
  for (Index = 0; Index < 10; Index++){
    SensorValue += analogRead(A0);
    delay(100);
  }
   float voltage = (SensorValue/Index) * (15.5 / 1023.0);
   Serial.println((String)"Input power: " + voltage + (String)" V");
   shortMenu();
}

//********************** MAIN MENU **********************

void shortMenu() {
  Serial.println(F("****************************************************************"));
  Serial.println(F("* 1.Stepper Motors | 2.Voltage | 3.MPU-6050 | 4.VL53L0X | 5.IR *"));
  Serial.println(F("****************************************************************\n"));
}

//********************** TEST MPU6050 **********************

void displayGyro() {
  mpu6050.calcGyroOffsets(true);
  Serial.println();
  for (int i = 0; i <= 300; i++){
    mpu6050.update();  
    Serial.print("angleX : ");
    Serial.print(mpu6050.getAngleX());
    Serial.print("\tangleY : ");
    Serial.print(mpu6050.getAngleY());
    Serial.print("\tangleZ : ");
    Serial.println(mpu6050.getAngleZ());
  }
  shortMenu();
}

//********************** TEST VL53L0X **********************

void displayVL53L0X() { 
  for (int i = 0; i <= 300; i++){
  //Serial.println((String)"S1 Distance: " + sensor1.readRangeContinuousMillimeters() + (String)" mm");
  //delay(1000);
  Serial.println((String)"S2 Distance: " + sensor2.readRangeContinuousMillimeters() + (String)" mm");
  if (sensor1.timeoutOccurred()) { Serial.print(" TIMEOUT"); }
  if (sensor2.timeoutOccurred()) { Serial.print(" TIMEOUT"); }
  }
  shortMenu();
}

//************************* IR *************************

void displayIR() { 
  for (int i = 0; i <= 300; i++){
  String ir_1 = ( digitalRead(IR_1) == HIGH ) ? "On" : "Off";
  String ir_2 = ( digitalRead(IR_2) == HIGH ) ? "On" : "Off";
  String ir_3 = ( digitalRead(IR_3) == HIGH ) ? "On" : "Off";
  String ir_4 = ( digitalRead(IR_4) == HIGH ) ? "On" : "Off";
  Serial.println(ir_1 + (String)" | " + ir_2 + (String)" | " + ir_3 + (String)" | " + ir_4); 
  }
  shortMenu();
}

void Test()
{
  Serial.println ("I2C scanner. Scanning ...");
  byte count = 0;


  for (byte i = 1; i < 120; i++)
  {

    Wire.beginTransmission (i);
    if (Wire.endTransmission () == 0)
    {
      Serial.print ("Found address: ");
      Serial.print (i, DEC);
      Serial.print (" (0x");
      Serial.print (i, HEX);
      Serial.println (")");
      count++;
      delay (1);  // maybe unneeded?
    } // end of good response
  } // end of for loop
  Serial.println ("Done.");
  Serial.print ("Found ");
  Serial.print (count, DEC);
  Serial.println (" device(s).");

  delay(3000);
}

JonathanKosh · February 27, 2019, 11:07pm

Hello.

I am sorry you are having trouble getting multiple VL53L0X working together in your system. It looks like in your code you are trying to set your I²C slave addresses while both sensors are powered and connected to the I²C bus, which means that both sensors receive both commands. So, the net effect of those commands is that both sensors have the slave address of the last setAddress() command (i.e. they are both 25). Are you somehow not powering one of those boards during the brief time that you are setting their device addresses? XSHUT is useful for setting different I²C slave addresses; it can be used to disable one of the boards so that your setAddress() command is only received by the intended VL53L0X. We don’t know of any other way to effectively work with multiple VL53L0X sensors unless you otherwise have a way to isolate communications to one at a time.

-Jon

GarrettC · February 27, 2019, 11:33pm

Thanks for the response. Currently the code isn’t even managing to get past initiating the first sensor which is odd. It did manage this until we adjusted the values for the addresses.

Unfortunately I am unable to use the XSHUT pin currently as I am using a custom PCB built as a shield. The issue is that the design only has the 4 pins. I understand the general idea of the XSHUT pin and I can see how it would be useful in solving my problem. Unfortunately I wasn’t the one tasked with designing the board I was just the one told to program it.

I have included the schematic of the PCB and an image of the assembled one encase these help explain the issue or give anyone some ideas on how to go about solving this.

GarrettC · February 27, 2019, 11:34pm

Also a side view for extra context. As a side note I also didn’t assemble the board, wouldn’t have left it this shabby myself.

JonathanKosh · February 28, 2019, 8:21pm

Like I mentioned in my initial reply, we do not really have an effective solution for working with multiple VL53L0X sensors that does not use XSHUT. If the XSHUT pins are accessible in your setup, you might consider soldering wires directly between them and a couple pins on your Arduino.

-Jon

GarrettC · March 1, 2019, 11:59am

Yeah I appreciate that you don’t know of an effective solution besides the XSHUT pins and I am looking at ways of using any spare output pins from the board to either drive another board to toggle the XSHUT pins or if there are enough free outputs doing direct. I appreciate the help. Still doesn’t solve the issue with the code stalling at the sensor1.init() but perhaps the issue is linked to both sensors being on so I will investigate.

JonathanKosh · March 1, 2019, 7:36pm

Testing a single VL53L0X is a good start to troubleshooting your initialization issue. Then, using known-working libraries and code is an appropriate next step (e.g. does running our Single or Continuous example sketch work?) Are you using our carrier board?

-Jon

GarrettC · March 11, 2019, 11:22pm

Sorry for the delay there.

Yeah got the init stuff to work and for a short while got the sensors to work properly using the XSHUTs the only issue now is I messed up and lost the working stuff. So if you could correct me if I am wrong on the procedure here it would help.

Set XSHUT pins to INPUT
delay
Set XSHUT pins to OUTPUT
delay

Set address 1
delay
Set an XHSHUT to input
delay
Set address 2

Something like that?

I have been trying to fix it again but sensor 1 keeps giving a reading of 65000 ish while sensor 2 provides actual results.

Alternatively I may just set it up so that I only power and initialise the one I want to record values from when it’s needed. Not as fast to do it that way but might be a last ditch solution.

JonathanKosh · March 12, 2019, 8:39pm

It looks like you are trying to set address 1 while neither board is enabled. Here is what is happening in your pseudocode:

Set XSHUT pins to INPUT 	// all XSHUT pins set to high-impedance, enabling all Pololu VL53L0X carrier boards*
delay 				        // waiting
Set XSHUT pins to OUTPUT	// all XSHUT pins are driven LOW, which places all VL53L0X in standby mode
delay				        // waiting

Set address 1		      	// send a set address command (no VL53L0X are enabled, so none receive this command)
delay				        // waiting
Set an XHSHUT to input		// a single XSHUT pin is set to high-impedance, enabling a single VL53L0X
delay				        // waiting
Set address 2			    // send a set address command; a single VL53L0X receives this command

* Pololu VL53L0X carrier boards have a pull-up resistor on XSHUT, so they are enabled by default.

The result of your pseudocode is that one VL53L0X retains the default slave address and another is set to “address 2”, which probably explains the behavior you are getting. Although it does not seem like your intent, that setup should still allow you to communicate with both time-of-flight sensors on the same I²C bus.

-Jon