Array Data Reading Failed - arrays

Question

I am reading the data from a "Torque Wrench" using "USB Host Shield2.0" and Arduino UNO. I am receiving correct data from my "Torque Wrench" Data is receiving in a array.
But when I started reading data after "for" loop inside Void loop() I am receiving incorrect data. I attached Both output pictures correct and incorrect data.
Basically I am read data from Torque Wrench and send to receiver using Nrf24l01. I am receiving incorrect data.
My question is :- Why I am reading Incorrect data outside "for" loop.
Correct Data inside "for" loop :- enter image description here
Incorrect Data outside "for" loop :- enter image description here
#include <SPI.h> // for SPI communication
#include <nRF24L01.h>
#include <RF24.h>
#include <cdcacm.h>
#include <usbhub.h>
//#include "pgmstrings.h"
// Satisfy the IDE, which needs to see the include statment in the ino too.
#ifdef dobogusinclude
#include <spi4teensy3.h>
#endif
#include <SPI.h>
RF24 radio(7, 8); // CE, CSN
const byte address[6] = {'R','x','A','A','A','B'}; // the address the the module
class ACMAsyncOper : public CDCAsyncOper
{
public:
uint8_t OnInit(ACM *pacm);
};
uint8_t ACMAsyncOper::OnInit(ACM *pacm)
{
uint8_t rcode;
// Set DTR = 1 RTS=1
rcode = pacm->SetControlLineState(3);
if (rcode)
{
ErrorMessage<uint8_t>(PSTR("SetControlLineState"), rcode);
return rcode;
}
LINE_CODING lc;
lc.dwDTERate = 9600;
lc.bCharFormat = 0;
lc.bParityType = 0;
lc.bDataBits = 8;
rcode = pacm->SetLineCoding(&lc);
if (rcode)
ErrorMessage<uint8_t>(PSTR("SetLineCoding"), rcode);
return rcode;
}
USB Usb;
//USBHub Hub(&Usb);
ACMAsyncOper AsyncOper;
ACM Acm(&Usb, &AsyncOper);
void setup() {
Serial.begin(9600);
radio.begin();
radio.openWritingPipe(address);
radio.setPALevel(RF24_PA_MAX);
radio.stopListening();
#if !defined(__MIPSEL__)
while (!Serial);
#endif
Serial.println("Start");
if (Usb.Init() == -1)
Serial.println("USB Not Connected");
delay( 200 );
}
void loop() {
Usb.Task();
if( Acm.isReady()) {
uint8_t rcode;
/* reading the keyboard */
if(Serial.available()) {
uint8_t data= Serial.read();
/* sending to the phone */
rcode = Acm.SndData(1, &data);
if (rcode)
ErrorMessage<uint8_t>(PSTR("SndData"), rcode);
}
delay(10);
uint8_t buf[64];
uint16_t rcvd = 64;
char text[64];
rcode = Acm.RcvData(&rcvd, buf);
if (rcode && rcode != hrNAK)
ErrorMessage<uint8_t>(PSTR("Ret"), rcode);
if ( rcvd ) {
for(uint16_t i=0; i < rcvd; i++ )
{
// Serial.print((char)buf[i]); // correct Data read from torque wrench
text[i] = (char)buf[i];
}
Serial.println(text); // reading wrong data here
//radio.write(&text, sizeof(text));
//Serial.println(text);
}
delay(10);
}
}

Answer 1

Character arrays must be null-terminated to count as C strings.
After the for loop, add text[rcvd] = '\0';
Also, your rcvd is fixed at 64. It needs to be one less than the array size for the null terminator to fit.