RTscan

How to Use an Embedded 2d and QR barcode scanner with Arduino microcontroller (MCU)

If you are using an Arduino MCU (microcontroller) to develop your system and need an embedded 1D/ 2D QR barcode scanner to work with it, this article will be helpful. Here, we introduce how we connect the Arduino Uno microcontroller with RTscan embedded 2d & QR barcode scanners and make them work together.

When we try to integrate a QR barcode scanner with the Arduino microcontroller board, we would meet these problems:

  1. The QR barcode scanner normally comes with a USB and RS232 cable, but if the Arduino board does not have this type of connector, how can we connect them together?
  2. Whatever QR barcode scanners we choose, how can we control them with Arduino and upload decoded data to the Arduino system?

Read below and find out how RTscan provides solutions for the above questions.

Contents

Part I: Introduction of Arduino UNO and RTscan embedded barcode scanner

Part II: Connection solutions

  • Connect via USB interface via USB Host Shield

Part III: Sample code/ Control the QR barcode scanner via Arduino system

  • USB CDC Communication
  • USB-HID Communication

Part VI: Video Demo

 
 

Part I:  Introduction of Arduino UNO and RTscan QR barcode scanner

Arduino UNO: The UNO is the most used and documented board of the whole Arduino microcontroller family. Many people choose this model for their projects. Arduino Uno has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, an ICSP header, and a reset button. It contains everything needed to support the microcontroller.

Arduino UNO:

Arduino UNO Pinout

RTscan QR barcode scanners:

In this article, we choose RT870 and RT830C as examples to introduce our solutions.

 

Part II: Connection solutions:

 

Connect the 2D QR barcode scanner via USB interface ( here we  take RT870 as an example)

You can also choose our RT870 for your solution: use an Arduino USB host shield as shown below.

 

Part III: Sample code/ Control the QR barcode scanner via Arduino system

We developed sample code to work with our scanners so that you can copy our source code and program your system very quickly, without needing to write the whole code one by one; save your time and speed up your integration work!

 

1 . USB CDC (USB virtual COM) Communication 

In this solution, the scanner is set to USB COM port emulation mode, and the Arduino recognizes the scanner via the USB host shield.

Step 1: Hardware connection

Connect the RT870 scanner to the USB port of the Arduino USB host shield through a USB data cable.

Step 2: RT870 settings

RT870 set to USB CDC mode, scan the following Setting bar code

Firstly, Set to USB cable

Then, Set to USB-CDC mode

*Recognized as USB com port device on the computer.

Step 3:Include the library

Arduino Library Manager

First, install Arduino IDE version 1.6.2 or newer, then simply use the Arduino Library Manager to install the library.

Please see the following page for instructions:

http://www.arduino.cc

Manual installation

First, download the library by clicking on the following link:

https://github.com/felis/USB_Host_Shield_2.0

Then uncompress the zip folder and rename the directory to “USB_Host_Shield_20”, as any special characters are not supported by the Arduino IDE.

Now open up the Arduino IDE and open “File>Preferences”. There you will see the location of your sketchbook. Open that directory and create a directory called “libraries” inside that directory. Now move the “USB_Host_Shield_20” directory to the “libraries” directory.

The final structure should look like this:

  • Arduino/
    • libraries/
      • USB_Host_Shield_20/

Now quit the Arduino IDE and reopen it.

Now you should be able to open all the examples codes by navigating to “File>Examples>USB_Host_Shield_20”, and then select the example.

For more information please visit the following sites:

http://arduino.cc/en/Guide/Libraries

Step 4: Run the sample code

Run: acm_terminal. ino 

#include 
#include 

#include "pgmstrings.h"

// Satisfy the IDE, which needs to see the include statment in the ino too.
#ifdef dobogusinclude
#include 
#endif
#include 

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(PSTR("SetControlLineState"), rcode);
        return rcode;
    }

    LINE_CODING	lc;
    lc.dwDTERate	= 115200;
    lc.bCharFormat	= 0;
    lc.bParityType	= 0;
    lc.bDataBits	= 8;

    rcode = pacm->SetLineCoding(&lc);

    if (rcode)
        ErrorMessage(PSTR("SetLineCoding"), rcode);

    return rcode;
}

USB     Usb;
//USBHub     Hub(&Usb);
ACMAsyncOper  AsyncOper;
ACM           Acm(&Usb, &AsyncOper);

void setup()
{
  Serial.begin( 115200 );
#if !defined(__MIPSEL__)
  while (!Serial); // Wait for serial port to connect - used on Leonardo, Teensy and other boards with built-in USB CDC serial connection
#endif
  Serial.println("Start");
  Serial.println("Please set the scanner to USB CDC mode");

  if (Usb.Init() == -1)
      Serial.println("OSCOKIRQ failed to assert");

  delay( 200 );
}
... Please contact us to get full sample codes: sales@rtscan.net
 

Open the serial port for debugging

Scan any barcode and it will be shown as below:

 

2. USB-HID Communication

In this solution, the scanner is set to USB HID KBW mode. The Arduino recognizes the scanner via the USB host shield.

Step 1: Hardware connection

Connect the RT870 scanner to the Arduino USB host shield’s USB port using a USB data cable.

Step 2: RT870 settings

RT870 set to USB-HID mode, scan the following Setting bar code

Set to the USB output

Set to USB-HID mode

*Recognized as a HID Keyboard Device on the computer.

 

Step 3: Include the library

Arduino Library Manager

First, install Arduino IDE version 1.6.2 or newer, then simply use the Arduino Library Manager to install the library.

Please see the following page for instructions:

http://www.arduino.cc/

Manual installation

First, download the library by clicking on the following link:

https://github.com/felis/USB_Host_Shield_2.0

Then uncompress the zip folder and rename the directory to “USB_Host_Shield_20”, as any special characters are not supported by the Arduino IDE.

Now open up the Arduino IDE and open “File>Preferences”. There you will see the location of your sketchbook. Open that directory and create a directory called “libraries” inside that directory. Now move the “USB_Host_Shield_20” directory to the “libraries” directory.

The final structure should look like this:

  • Arduino/
    • libraries/
      • USB_Host_Shield_20/

Now, quit the Arduino IDE and reopen it.

Now you should be able to open all the examples codes by navigating to “File>Examples>USB_Host_Shield_20”, and then select the example.

For more information, please visit the following sites: 

http://arduino.cc/en/Guide/Libraries 

https://learn.adafruit.com/adafruit-all-about-arduino-libraries-install-use.

 

Step 4: Run the sample code

Run:

Scanner_USBHIDUniversalKbd. ino

#include 
#include 
#include 

#include 

class KbdRptParser : public KeyboardReportParser
{
  public:
    void PrintKey(uint8_t mod, uint8_t key);

    bool isScanEnd();
    void PrintScanCode();

  protected:
    void OnControlKeysChanged(uint8_t before, uint8_t after);

    void OnKeyDown  (uint8_t mod, uint8_t key);
    void OnKeyUp    (uint8_t mod, uint8_t key);
    void OnKeyPressed(uint8_t key);

    String ScanCode = "";
    uint32_t FreeTime = 0;
    bool StartScan = false;
};

void KbdRptParser::PrintKey(uint8_t m, uint8_t key)
{
  MODIFIERKEYS mod;
  *((uint8_t*)&mod) = m;
  Serial.print((mod.bmLeftCtrl   == 1) ? "C" : " ");
  Serial.print((mod.bmLeftShift  == 1) ? "S" : " ");
  Serial.print((mod.bmLeftAlt    == 1) ? "A" : " ");
  Serial.print((mod.bmLeftGUI    == 1) ? "G" : " ");

  Serial.print(" >");
  PrintHex(key, 0x80);
  Serial.print("< ");

  Serial.print((mod.bmRightCtrl   == 1) ? "C" : " ");
  Serial.print((mod.bmRightShift  == 1) ? "S" : " ");
  Serial.print((mod.bmRightAlt    == 1) ? "A" : " ");
  Serial.println((mod.bmRightGUI    == 1) ? "G" : " ");
};

void KbdRptParser::OnControlKeysChanged(uint8_t before, uint8_t after) {

  MODIFIERKEYS beforeMod;
  *((uint8_t*)&beforeMod) = before;

  MODIFIERKEYS afterMod;
  *((uint8_t*)&afterMod) = after;

  if (beforeMod.bmLeftCtrl != afterMod.bmLeftCtrl) {
    Serial.println("LeftCtrl changed");
  }
  if (beforeMod.bmLeftShift != afterMod.bmLeftShift) {
    Serial.println("LeftShift changed");
  }
  if (beforeMod.bmLeftAlt != afterMod.bmLeftAlt) {
    Serial.println("LeftAlt changed");
  }
  if (beforeMod.bmLeftGUI != afterMod.bmLeftGUI) {
    Serial.println("LeftGUI changed");
  }

  if (beforeMod.bmRightCtrl != afterMod.bmRightCtrl) {
    Serial.println("RightCtrl changed");
  }
  if (beforeMod.bmRightShift != afterMod.bmRightShift) {
    Serial.println("RightShift changed");
  }
  if (beforeMod.bmRightAlt != afterMod.bmRightAlt) {
    Serial.println("RightAlt changed");
  }
  if (beforeMod.bmRightGUI != afterMod.bmRightGUI) {
    Serial.println("RightGUI changed");
  }

}

void KbdRptParser::OnKeyDown(uint8_t mod, uint8_t key)
{
  Serial.print("DN ");
  PrintKey(mod, key);
  uint8_t c = OemToAscii(mod, key);

  if (c){
    OnKeyPressed(c);
  }
}

void KbdRptParser::OnKeyUp(uint8_t mod, uint8_t key)
{
  // Serial.print("UP ");
  // PrintKey(mod, key);
  
  FreeTime = millis();
  StartScan = true;
}

void KbdRptParser::OnKeyPressed(uint8_t key)
{
  Serial.print("ASCII: ");
  Serial.println((char)key, HEX);
  // ScanCode = ScanCode + String((char)key);
};

bool KbdRptParser::isScanEnd()
{
  if(millis() - FreeTime > 200 && StartScan){
      StartScan = false;
      return true;
  }

  return false;
};

void KbdRptParser::PrintScanCode()
{
  Serial.print("ScanCode: ");
  Serial.println(ScanCode);
  ScanCode = "";
};

USB          Usb;
HIDUniversal Hid(&Usb);
KbdRptParser Prs;

void setup()
{
  Serial.begin( 115200 );
#if !defined(__MIPSEL__)
  while (!Serial); // Wait for serial port to connect - used on Leonardo, Teensy and other boards with built-in USB CDC serial connection
#endif
  Serial.println("Start");
  Serial.println("Please set the scanner to USB HID mode");

  if (Usb.Init() == -1)
    Serial.println("OSC did not start.");

  delay( 200 );

  Hid.SetReportParser(0, &Prs);
}


Please contact us to get full sample codes: sales@rtscan.net

Open the serial port for debugging

Scan any barcode, and it will be shown as below:

 

Part VI: Video Demo

Please refer to the following video for specific operations:

If you need an OEM barcode scanner module for Arduino, please read: 

Arduino Barcode Scanner

If you need an OEM barcode scanner for Raspberry Pi, please read:

Raspberry Pi Barcode Scanner

If you need an embedded barcode scanner for Raspberry Pi, please read:

Embedded barcode scanner for Raspberry Pi

Related Products:

Fixed mount 2d Barcode Scanner: RT240

Fixed-mount embedded & Kiosk Barcode Scanner: RT830C

OEM 2D Barcode Reader: RT214

Embedded 2D Barcode And QR Code Reader: RT870

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