iRobot Create 2 - How did I get weird data from the serial port?

Question

I'm new to Roomba Create2.

I just want the program to send and receive data of the bumper sensor only.

I tried this code on an Arduino Uno:

#include <SoftwareSerial.h>
#include "roombaDefines.h"
int rxPin = 10;
int txPin = 11;
int sensorbytes;
SoftwareSerial Roomba(rxPin, txPin);
void setup()
{
  Roomba.begin(19200);
  Serial.begin(9600);
  pinMode(ddPin, OUTPUT);
  wakeUp ();   // Wake-up Roomba
  startSafe(); // Start Roomba in Safe Mode
  setPowerLED(128, 255);
  delay(1000);
  setPowerLED(128, 0);
  delay(1000);
}
void loop() 
{  
  Roomba.write(142);
  Roomba.write(7);
  delay(100);
  sensorbytes = Roomba.read();

   if (sensorbytes!=0 )
   {
    setPowerLED(255,255);
    Serial.println(sensorbytes);
   }
   else
   {
    setPowerLED(255,0);
    Serial.println("not_Press");
   }
   delay(100);
}

The robot code works fine for a period of time but after about two minutes I got some weird data from the robot (it shows in my serial monitor) and it makes my program seem to delay and crash.

So I tried to check where it comes from

void loop() 
{

int i = 0;

  while(Roomba.available() ) {
    byte c = Roomba.read();
    sensorbytes = c;
    Serial.println(sensorbytes);
    i++;
  }
  delay(150);
}

to check that the robot sends data via the serial port or not. Even if I don't command it, I get a packet of data, maybe every two minutes:

32
32
32
32
70
108
97
115
104
32
67
82
67
32
115
117
99
148
205
205
233
32
48
120
48
32
40
48
120
48
41
10
13

and it is the same. So I think that the Roomba Create2 will send data via the serial port every two minutes.

Can I avoid that data?

Answer 1

You might want to take a look at the iRobot Create 2 OI spec https://www.irobotweb.com/~/media/MainSite/PDFs/About/STEM/Create/iRobot_Roomba_600_Open_Interface_Spec.pdf

I'm using a different controller so I can't test your code. Just be sure you are set for 115,200 baud.

You might also want to try sending a 128,7 command to fully reset the Create 2 before starting to send your 142,7 sensor read command which should only return a single byte on every command

You might also want to send the recommended "start" command