Serial Plotter is a programm that can receive data from any electronic board and reprent the result on very nice graph.
The program can manager up to four channels and has Free run and append feature.
the programm use a simple protocol to ease the task for fast developpement of a code on the hardware side.
The protocol is as follow :
string command = NumberOfSamples.ToString() + “,” + SamplingTimeuS.ToString() + “,” + activatedChannels + “,” + FreeRunCmd;

Explination :
NumberOfSamples : How many samples (points) you want to receive.
SamplingTimeuS : sampling time in micro seconds
activatedChannels : is a string of 4 bits, each bit represent a channel
example : 0001 : Channel 0 is activated and the others deactivated
1010 : channel 1 and 3 activated and channels 0 and 2 deactivated.
FreeRunCmd : not used for now.

Here is an arduino code to test :

#include <TimerOne.h>

unsigned int sensorValue[4] ; //= 0;

String inputString = “”; // a String to hold incoming data
unsigned long int count = 0;
unsigned long int NbrPoints = 0;
unsigned int activatedChannels = 1;
unsigned int freeRunCmd = 0;
bool SendingStarted = false;

unsigned int MaxChannels = 4;

void setup() {

Serial.begin(115200);
inputString.reserve(200);
Timer1.initialize(1000);
Timer1.stop();
}
void serialSend(void)
{
count++;
for(int i=0 ; i< MaxChannels ; i++)
{
if (((activatedChannels >> i )& 0x01) == 1)
{
if(SendingStarted)
{
Serial.print(“,”);
}
sensorValue[i] = analogRead(i);
Serial.print(sensorValue[i]);
SendingStarted=true;
}

  }    
  
  if (count<= NbrPoints-1)
  {
    Serial.print(";");
  }
  else
  {
      Serial.println("\n\r"); 
      Timer1.detachInterrupt(); //Timer1.stop();   
  }
  SendingStarted=false;

}
void loop() {
}

void serialEvent() {
inputString= Serial.readStringUntil(‘\n’);
unsigned int firstCommaIndex = inputString.indexOf(‘,’);
unsigned int secondCommaIndex = inputString.indexOf(‘,’, firstCommaIndex+1);
unsigned int thirdCommaIndex = inputString.indexOf(‘,’, secondCommaIndex+1);
unsigned int fourthCommaIndex = inputString.indexOf(‘,’, thirdCommaIndex+1);

  String NbrPointsCmd     = inputString.substring(0, firstCommaIndex);
  String TimerParam       = inputString.substring(firstCommaIndex+1, secondCommaIndex);
  String activatedChannelsCmd = inputString.substring(secondCommaIndex+1, thirdCommaIndex);
  String freeRun          = inputString.substring(thirdCommaIndex+1, inputString.length());
  
  //inputString="";

  NbrPoints = NbrPointsCmd.toInt();
  unsigned long int Timer1Step=TimerParam.toInt();
  activatedChannels=activatedChannelsCmd.toInt();
  freeRunCmd = freeRun.toInt();
  count=0; 
  
  Timer1.setPeriod(Timer1Step);
  Timer1.attachInterrupt(serialSend);
  Timer1.start();

}