Reading multiple parameters through serial port using delimiter (,)

Projects Programming
1

Hi friends!

I have been trying to receive two parameters through serial port at the same time (using , as delimiter) but I always get the second one as zero. I don't know whats wrong with code. Can anyone point out my mistake?

unsigned long T, T0, T1, T2, T3, T4, t, t_start, t1, t2, t3, t4;
boolean signal_ON;
boolean flag = 1;
int user_command = 0;
int user_command2 = 8000;
int Vlow1, Vhigh1;
int v;
String comdata = "";
int numdata[12] = {0}, Users_Parameters[12] = {3, 5, 6, 9, 10, 11, 12, 13, 14, 15, 16, 17}, mark = 0; //numdata is array of numbers after splitting
int Camera_power = 6; //Camera Power Supply
int Laser_power = 7; //Laser Power Supply
int Camera_signal = 3; //Camera Signal
int Laser_signal = 2; //Laser Signal
int Switch_pos = 10; //+24V Switch
int Switch_neg = 12; //-24V Switch

void setup() {

  t1 = 30000;
  t2 = 20479;
  t3 = 1000;
  t4 = 2000;
  T0 = 0;
  T1 = t1;
  T2 = t1 + t2;
  T3 = t1 + t2 + t3;
  T4 = t1 + t2 + t3 + t4;
  T = t1 + t2 + t3 + t4;
  t = T + 1;

  Vlow1;
  Vhigh1;
  signal_ON = true;

  pinMode(Camera_signal, OUTPUT);
  pinMode(Laser_signal, OUTPUT);
  pinMode(Laser_power, OUTPUT);
  pinMode(Switch_pos, OUTPUT);
  pinMode(Switch_neg, OUTPUT);


  analogWriteResolution(12);
  digitalWrite(Camera_signal, LOW);
  digitalWrite(Laser_signal, LOW);
  digitalWrite(Laser_power, LOW);
  digitalWrite(Switch_pos, HIGH);
  digitalWrite(Switch_neg, HIGH);
  Serial.begin(9600);
  Serial.println("Enter a command:");
  Serial.println("For Switching on the Camera, Enter 1");
  Serial.println("For Switching off the Camera, Enter 2");
  Serial.println("For Switching on the Laser, Enter 3");
  Serial.println("For Switching off the Laser, Enter 4");
  Serial.println("For Switching on the Scanner, Enter 5");
  Serial.println("For Switching off the Scanner, Enter 6");
  Serial.println("For changing the laser/scanner high time, Enter 7, value for laser/scanner high");
  Serial.println("For changing the camera high time, Enter 8, value for Camera");
  Serial.println("For changing the camera exposure time, Enter 9, value for Camera exposure");
  Serial.println("For changing the angle of scanner, Enter 10, Value of Scanner between 0 to 4095 ");
  Serial.println("For Switching on the Signal_ON, Enter 11");
  Serial.println("For Switching off the Signal_ON, Enter 12");


}

void loop() {


  PIV_Preset();
  Users_Parameter_Acquisition();


}

void PIV_Preset()
{

  int j = 0;
  if (signal_ON)
  { T1 = t1;

    if (t > T)
    {
      t_start = micros();
    }

    t = micros() - t_start;
    if (t < T1)
    {
      flag = 0;
      digitalWrite(Camera_signal, HIGH);
    }

    if (t > T1)
    { T0 = 0;
      T2 = t1 + t2;
      T3 = t1 + t2 + t3;
      T4 = t1 + t2 + t3 + t4;
      T = t1 + t2 + t3 + t4;
      flag = 0;
      v = map(t, T1, T2, Vlow1, Vhigh1);
      analogWrite(DAC1, v);
      //digitalWrite(Laser_signal, HIGH);

    }
    if (t > T2)
    {
      flag = 0;
      digitalWrite(Laser_signal, LOW);
    }

    if (t > T3)
    {
      flag = 0;
      digitalWrite(Camera_signal, LOW);
    }
  }
}

void Users_Parameter_Acquisition()
{ int j = 0;
  while ((Serial.available() > 0))
  {
    // Read in the string and connect it to comdata
    comdata += char(Serial.read());
    delay(2);
    mark = 1;
  }

  if (mark == 1) //If data is received perform comdata analysis otherwise do nothing
  {
    //Display the string just entered (optional)
    Serial.println(comdata);

    for (int i = 0; i < comdata.length() ; i++)
    {
      if (comdata[i] == ', ')
      {
        j++;
      }
      else
      {
        numdata[j] = numdata[j] * 10 + (comdata[i] - '0');
      } 

    }
    //Comdata strings have been converted to numdata. Clear comdata for next use
    //If you don't clear it, this result is likely to interfere with the next time.


    comdata = String("");
   
    //The content of numdata are output in a cycle and written to Users_Parameters[]

    for (int i = 0; i < 12; i++)
    {
      Users_Parameters[i] = numdata[i];
      numdata[i] = 0;
    }
    user_command = int(Users_Parameters[0]);
    user_command2 = int(Users_Parameters[1]);
    
    if (user_command == 1)     {
      Serial.println("Camera On");
      digitalWrite(Camera_power, HIGH);
    }
    else if (user_command == 2) {
      Serial.println("Camera Off");
      digitalWrite(Camera_power, LOW);
    }
    else if (user_command == 3) {
      Serial.println("Laser On");
      digitalWrite(Laser_signal, HIGH);
    }
    else if (user_command == 4) {
      Serial.println("Laser Off");
      digitalWrite(Laser_signal, LOW);
    }
    else if (user_command == 5) {

      Serial.println("Scanner On");

      int v = map(t, 0, T, 0, 4095);
      analogWrite(DAC1, v);

    }
    else if (user_command == 6) {
      Serial.println("Scanner Off");
      analogWrite(DAC1, Vlow1);
    }

else if (user_command == 7) {
      t2 = user_command2;
      Serial.println(t2);
 
    }
    
    else if (user_command == 8) {
      t3 = user_command2;
      Serial.println(t3);
    }
    
    else if (user_command == 9) {
      t4 = user_command2;
      Serial.println(t4);
    }
    
    else if (user_command == 10) {
      Vhigh1 = user_command2;
      Serial.println(Vhigh1);
    }

    else if (user_command == 11) {
      Serial.println("Signal On");
      signal_ON = true;
    }
    
    else if (user_command == 12) {
      Serial.println("Signal Off");
      signal_ON = false;
    }

    else
    {
      delay(10);
    }

    //After output, the mark read to data must be set to 0. If it is not set to 0, the next cycle cannot be used
    mark = 0;
    flag = 1;
  }
}

PIV_Arduino.ino (5.51 KB)

2

Most probably something is wrong with these parts:

for (int i = 0; i < 12; i++)
{
Users_Parameters = numdata*;*
_ numdata = 0;
* }_
user_command = int(Users_Parameters[0]);
user_command2 = int(Users_Parameters[1]);
if (user_command == 7) {
t2 = user_command2;
_ Serial.println(t2);*_

* }*
Whenever I print value of t2, its always zero.

3

First it is impossible, if you want to receive both concurrently with one serial port. you need two serial ports. The software serial only allows one channel at a time. Since you did not state which Arduino you are using look at the Mega, it has three ports available and all three can receive concurrently. I hope this helps.

4

Thanks for your time. I am using Arduino Due. I meant to say that when I enter 7, 1000 in serial port. 1000 should be transferred to user_command2. Is that possible?

5

Have a look at the examples in Serial Input Basics - simple reliable non-blocking ways to receive data. There is also a parse example to illustrate how to extract numbers from the received text.

...R

6

Also avoid using Strings.

7

Robin2:
Have a look at the examples in Serial Input Basics - simple reliable non-blocking ways to receive data. There is also a parse example to illustrate how to extract numbers from the received text.

...R

Thanks a lot. I already used the example you mentioned and it worked. But for knowledge's sake, can you point out the basic mistake in my code?

8

BJHenry:
Also avoid using Strings.

What problems does string use cause in general?

9

nauman_khan_93:
But for knowledge's sake, can you point out the basic mistake in my code?

Might be this:

      if (comdata[i] == ', ')

There are two characters enclosed in single quotes. Single quotes are for a single character. Double quotes are for string literals - a trailing null character is added.

Websearch 'C++ single quote'.

nauman_khan_93:
What problems does string use cause in general?

Memory fragmentation which leads eventually to unexpected/unwanted behavior.

10

Thanks a lot dougp. I got it.