APC220 and Arduino Mega Problem TX and RX ing at the same time

Hi to all

i hope anyone has any ideas on what might be wrong with my setup/code.

I can't seem to able to get a pair of APC220 to TX and RX and the same time using TX RX 3 on the Arduino mega.

I can get it to Radio TX data to my PC. But if i send a bit of data back using serial monitor "R" for reset no joy.

Stop the code Radio TX-ing (comment out the prints).....and it works "R" resets my code ??? :~

Strange thing is i can do both just fine simultaniusly using the USB cable ?

0	RPM	0.00	MPH	0.00	MaxMPH	10	IntBat	82	KartBat	123	Amps	66.35	Pack V	8	KW	10.94	HP	23	M Temp	00:00:05.643	Time
0	RPM	0.00	MPH	0.00	MaxMPH	10	IntBat	82	KartBat	123	Amps	66.35	Pack V	8	KW	10.94	HP	23	M Temp	00:00:05.875	Time
0	RPM	0.00	MPH	0.00	MaxMPH	10	IntBat	82	KartBat	123	Amps	66.35	Pack V	8	KW	10.94	HP	23	M Temp	00:00:06.107	Time

I would be very grateful if anyone knows any info on what might be causing this to happen.

  /////TX the info to base
  Serial3.print(rpm);
  Serial3.print("\t");
  Serial3.print("RPM");
  Serial3.print("\t");
  Serial3.print(mph);
  Serial3.print("\t");
  Serial3.print("MPH");
  Serial3.print("\t");
  Serial3.print(MaxMPH);
  Serial3.print("\t");
  Serial3.print("MaxMPH");
  Serial3.print("\t");
  Serial3.print(chargedisplaypercent);
  Serial3.print("\t");
  Serial3.print("IntBat");
  Serial3.print("\t");
  Serial3.print(chargedisplaypercent2);
  Serial3.print("\t");
  Serial3.print("KartBat");
  Serial3.print("\t");
  Serial3.print(amps);
  Serial3.print("\t");
  Serial3.print("Amps");
  Serial3.print("\t");
  Serial3.print(PackVoltage);
  Serial3.print("\t");
  Serial3.print("Pack V");
  Serial3.print("\t");
  Serial3.print(KW);
  Serial3.print("\t");
  Serial3.print("KW");
  Serial3.print("\t");
  Serial3.print(PackVoltage * amps / 746);
  Serial3.print("\t");
  Serial3.print("HP");
  Serial3.print("\t");
  Serial3.print(Temp1);
  Serial3.print("\t");
  Serial3.print("M Temp");
  Serial3.print("\t");
  print_time(millis() - time0);
  //Serial3.print(runtime);
  Serial3.print("\t");
  Serial3.println("Time");

   ////////////////////////////////////


/////Heres the reading sense for letter R code/////

    String input = ""; 
    // Read any serial input
    while (Serial3.available() > 0)
    {
        input += (char) Serial3.read(); // Read in one char at a time
        delay(5); // Delay for 5 ms so the next char has time to be received
    }
     
       
 if (input == "R")
 {
   MaxMPH = 0;
     
 }

Kind regards
James

Ive simplified my question a bit more, :fearful: