Arduino Usb Scanner Problem

Using Arduino Project Guidance
#1

Hello,

I have a question about using the USB Host Library 2.0 Bellow is the code. What i’m trying to do is when i scan a barcode to light a led, then wait until a switch is pressed to make it go off. The problem is when i scan the code, the scanner beeps 3 times and the red light comes up with error, like the buffer is not empty or something like that. I don’t know how to make the program to wait until the switch is pressed without the scanner entering in error mode.

Anyone can help? Thanks for your time. :slight_smile:

/*
 
Portable barcode scanner. Uses USB HID barcode scanner, Arduino Board, USB Host Shield and HD44780-compatible LCD display
 
  The circuit:
 * LCD RS pin to digital pin 7
 * LCD Enable pin to digital pin 6
 * LCD D4 pin to digital pin 5
 * LCD D5 pin to digital pin 4
 * LCD D6 pin to digital pin 3
 * LCD D7 pin to digital pin 2
 * LCD R/W pin to ground
 * 10K resistor:
 * ends to +5V and ground
 * wiper to LCD VO pin (pin 3)
 
*/
#include <string.h> 
#include <SPP.h>
#include <LiquidCrystal.h>
#include <avr/pgmspace.h>
#include <SPI.h> 
//#include <avrpins.h>
//#include <max3421e.h>
//#include <usbhost.h>
//#include <usb_ch9.h>
#include <Usb.h>
#include <usbhub.h>
#include <avr/pgmspace.h>
//#include <address.h>
#include <hidboot.h>
#include <hid.h>
#include <hiduniversal.h>
 
//#include <printhex.h>
//#include <message.h>
//#include <hexdump.h>
//#include <parsetools.h>
 
#define DISPLAY_WIDTH 16

const int button1 =  32;
const int button2 =  48;
const int ledPin1 =  8;
const int ledPin2 =  44;

String myString;
int val;
 
// initialize the LCD library with the numbers of the interface pins
LiquidCrystal lcd(7, 6, 5, 4, 3, 2);
 
USB     Usb;
USBHub     Hub(&Usb);
HIDUniversal   Hid(&Usb);
HIDBoot<HID_PROTOCOL_KEYBOARD>    Keyboard(&Usb);
 
class KbdRptParser : public KeyboardReportParser
{
     void PrintKey(uint8_t mod, uint8_t key);
     
protected:
	virtual void OnKeyDown	(uint8_t mod, uint8_t key);
	virtual void OnKeyPressed(uint8_t key);
};
 
void KbdRptParser::OnKeyDown(uint8_t mod, uint8_t key)	
{
    uint8_t c = OemToAscii(mod, key);
 
    if (c)
        OnKeyPressed(c);
}
 
/* what to do when symbol arrives */
 void KbdRptParser::OnKeyPressed(uint8_t key)	
{
static uint32_t next_time = 0;      //watchdog
static uint8_t current_cursor = 0;  //tracks current cursor position  
 
    if( millis() > next_time ) {
      lcd.clear();
      current_cursor = 0;
      delay( 5 );  //LCD-specific 
      lcd.setCursor( 0,0 );
    }//if( millis() > next_time ...
 
    next_time = millis() + 200;  //reset watchdog
 
    if( current_cursor++ == ( DISPLAY_WIDTH + 1 )) {  //switch to second line if cursor outside the screen
      lcd.setCursor( 0,1 );
    }
    
    val += key;   
    myString += char(key);
    //Serial.print(char(key));
    //Serial.println(key);    
    if (key==19){
          Serial.println(myString);
          Serial.println(val);
         
    switch (val) {
    case 274:         
          digitalWrite(ledPin1,HIGH);
          myString="";
          val=0;
          do {}
                while (digitalRead(button1)==HIGH);
          digitalWrite(ledPin1,LOW);
          
          break;
    case 530:
          digitalWrite(ledPin2,HIGH);
          myString="";
          val=0;
          do {}
                while (digitalRead(button2)==HIGH);
          digitalWrite(ledPin2,LOW);  
          break;
    default:
          myString="";
          val=0;
          break;
  }
            } 
                                 
    lcd.print( char(key) );
};
 
KbdRptParser Prs;
 
void setup()
{
    Serial.begin( 115200 );
    Serial.println("Start");
    
    if (Usb.Init() == -1) {
        Serial.println("OSC did not start.");
    }
 
    delay( 200 );
 
    Hid.SetReportParser(0, (HIDReportParser*)&Prs);
    // set up the LCD's number of columns and rows: 
    lcd.begin(DISPLAY_WIDTH, 2);
    lcd.clear();
    lcd.noAutoscroll();
    lcd.print("Ready");
    delay( 200 );
   
    pinMode(ledPin1,OUTPUT);
    pinMode(ledPin2,OUTPUT);
    pinMode(button1,INPUT_PULLUP);
    pinMode(button2,INPUT_PULLUP);
}
 
void loop()
{
  Usb.Task();
  
}
#2

I really need a suggestion if anyone could help?

#3

Do you have a simpler sketch that only exercises the scanner?

#4

Do you mean that the part that prints on the serial monitor the scanned barcode values?

#5

Do you mean the part that prints on the serial monitor the scanned barcode values?

#6

This is the part that prints on serial the values and the scanner enter in error mode when do while loop is being called:

val += key;   
    myString += char(key);
    //Serial.print(char(key));
    //Serial.println(key);    
    if (key==19){
          Serial.println(myString);
          Serial.println(val);
         
    switch (val) {
    case 274:         
          digitalWrite(ledPin1,HIGH);
          myString="";
          val=0;
          do {}
                while (digitalRead(button1)==HIGH);
          digitalWrite(ledPin1,LOW);
          
          break;
    case 530:
          digitalWrite(ledPin2,HIGH);
          myString="";
          val=0;
          do {}
                while (digitalRead(button2)==HIGH);
          digitalWrite(ledPin2,LOW);  
          break;
    default:
          myString="";
          val=0;
          break;
  }
#7

Anyone more experienced with some help please?

#8