Barcode Scanner DE2120 - Change single reading time or clear buffer

Sensors Imaging
1

Hey there,

I’m having some issues with the new Sparkfun barcode reader (https://www.sparkfun.com/products/18088).

I’m using it with an ESP 32 via UART and it kind of works pretty good.

I just would like to define the time, when the sensor is actually looking for barcodes.

The library offers the function .startScan(); and stopScan(); which work fine when using the board in “single scanning mode” but don’t when using the board in “continuous scanning mode”.

I’m using a slightly modified version of the example sketch:

 #include "SoftwareSerial.h"
SoftwareSerial softSerial(16, 17); 
#include "SparkFun_DE2120_Arduino_Library.h" 
DE2120 scanner;

#define BUFFER_LEN 40
char scanBuffer[BUFFER_LEN];

int button = 23;
int button_status = 0;
int button_pressed = 0;

void setup()
{

  pinMode(button, INPUT);

  Serial.begin(115200);
  Serial.println("DE2120 Scanner Example");

  if (scanner.begin(softSerial) == false)
  {
    Serial.println("Scanner did not respond. Please check wiring. Did you scan the POR232 barcode? Freezing...");
    while (1)
      ;
  }
  Serial.println("Scanner online!");

  scanner.enableContinuousRead(2); 
  
}

void loop()
{

  button_status = digitalRead(button);
  if(button_status == HIGH) button_pressed=1;

  if(button_pressed == 1 && button_status == LOW) {
   //when button is released
    scanner.startScan();
    button_pressed=0;
    delay(200);
  }


  if (scanner.readBarcode(scanBuffer, BUFFER_LEN)) {
    Serial.print("Code found: ");
    for (int i = 0; i < strlen(scanBuffer); i++) Serial.print(scanBuffer[i]);
    Serial.println();
    scanner.stopScan();
    delay(200);
  }

}

The scanner doesn’t really stop searching for barcodes when it found one. The lights turn off after it recognizes a barcode, so it seems like the scanner.stopScan(); worked, but when I turn the scanner on again using the button ```
scanner.startScan();


So it seems like the barcode is still in the buffer and fires immediately when the scanner is activated again.

It sometimes even fires a broken / wrong barcode from the buffer when started.

When using the barcode scanner in "single scanning mode" everything works fine, but the scanner turns off after 5 seconds if it doesn't recognize a barcode and it's not possible to change that time. Unfortunately I need to turn it off manually so that doesn't work for me. 

Maybe someone uses the same barcode scanner and has an idea how to solve the problem :)

It would be amazing if someone could help me! Thanks a lot!

Leo :)
2

Hi there,

So I’ve been pouring over the “Setting Manual” for the DE2120 and it’s pretty cryptic. I’ve been specifically looking at the “Continuous scanning mode” section. I believe the startScan() and stopScan() functions are intended for the manual/trigger mode, so I’m not sure how they will work in continuous reading mode. Have you considered using “Sense mode” pg 29? Would that work for what you’re trying to do? enableMotionSense()