QRCode Unit

The QRCode Unit is an integrated one-dimensional/two-dimensional code scanning unit that combines a CMOS QR code capture engine with a resolution of 640x480 and a bus conversion MCU (STM32F030). It features a device-side toggle switch that allows for switching between I2C and UART communication interfaces.

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QRCodeUnit

Micropython Example:

import os, sys, io
import M5
from M5 import *
from unit import QRCodeUnit
from hardware import *

def qrcode_0_event(qrdata):
    print(qrdata)

i2c0 = I2C(0, scl=Pin(1), sda=Pin(2), freq=100000)
qrcode_0 = QRCodeUnit(0, i2c0, 0x21)
qrcode_0.set_event_cb(qrcode_0_event)
qrcode_0.set_trigger_mode(1)

while True:
    qrcode_0.event_poll_loop()
    time.sleep_ms(25)

UIFLOW2 Example:

example.png

unit-qrcode-demo.m5f2

class QRCodeUnit

Constructors

class QRCodeUnit(mode, i2c, address, id, port)

Create a QRCodeUnit object

Parameters:

  • mode – 0: I2C, 1: UART mode.

  • i2c – the I2C object.

  • address – the I2C address of the device. Default is 0x21.

  • id – 1: UART1, 2: UART2.

  • port – uart pin tuple, which contains: (tx_pin, rx_pin)

UIFLOW2:

init.png

Methods

QRCodeUnit.get_qrcode_data_length()

Scan the QR code and get the available data length.

  • Return: int: available data length is int format

UIFLOW2:

get_qrcode_data_length.png

QRCodeUnit.get_qrcode_data()

Scan the QR code and get the data in the string.

  • Return: string: scanned data output is string format

UIFLOW2:

get_qrcode_data.png

QRCodeUnit.set_trigger_mode(mode)

Set the trigger mode to Auto or Manual(Key).

The parameters is:

  • mode: auto: 0 or manual: 1

UIFLOW2:

set_trigger_mode.png

QRCodeUnit.set_manual_scan(ctrl)

Set the manual(use the key button) scanning control ON or OFF.

The parameters is:

  • ctrl: off: 0 or on: 1

Note

This command is only effective in manual trigger mode

UIFLOW2:

set_manual_scan.png

QRCodeUnit.set_event_cb(qrcode_0_event)

Set the callback event and callback function.

The callback function:

  • qrcode_0_event

An handler showing a message has been received:

def qrcode_0_event(_qrdata):
    print(_qrdata)
    pass

UIFLOW2:

callback.png

QRCodeUnit.event_poll_loop()

The calling event poll block must be used inside a loop.

UIFLOW2:

event_poll_loop.png

QRCodeUnit.get_qrcode_data_status()

Reading data scanned QR code after get the data status

  • Return: int: 0: not ready, 1: data available, 2: read again

UIFLOW2:

get_qrcode_data_status.png

QRCodeUnit.get_trigger_mode()

Get the auto or manual trigger mode status.

  • Return: int: 0: auto, 1: manual

UIFLOW2:

get_trigger_mode.png

QRCodeUnit.get_trigger_button_status()

Get the trigger button status

  • Return: int: 1: press, 0: not pressed

UIFLOW2:

get_trigger_button_status.png

QRCodeUnit.get_device_info(info)

Get the firmware version details and I2C address of this device.

The parameters is:

  • info: 0xFE: firmware version, 0xFF: I2C address

UIFLOW2:

get_device_info.png

QRCodeUnit.clear_qrcode_data_status()

Clear the data status after reading the QR code scanned data.

UIFLOW2:

clear_qrcode_data_status.png

QRCodeUnit.set_device_i2c_address(addr)

The i2c address can be changed by the user and this address should be between 0x01 and 0x7F.

  • addr: range of address(0x01 - 0x7F).

UIFLOW2:

set_device_i2c_address.png