Line Encodings

Display Layout Overview

You control the layout of the display by specifying the content for up to five lines and a quantity parameter, using either the REST API or the QueryString API. Each of the five lines can contain simple text (scaled to maximum size to fit), a barcode, a QR-Code, or an icon.

The quantity parameter will display in a box on the upper left-hand corner of the display if the number is less than 64. If the quantity number is higher, it will display elsewhere.

Using Line Encodings with Commands vs. Statics

All the encoding techniques on this page work with both commands and statics:

Example: Same Display as Command and Static

# Temporary display with LED and button press
session.post(
    url + "device/DEVICE_ID/",
    headers=headers,
    json={
        'command': 'flash',
        'arrow': 'up',
        'line1': 'Pick Widget A',
        'barcode': 'SKU12345',
        'quantity': 3,
        'color': 'g',
        'seconds': 600
    }
)

Simple Text

Each line supports up to 26 Western characters. The shorter the text the better, both because it's easier to read and because the text will scale to fill the surrounding area.

session.post(
    url + "device/DEVICE_ID/",
    headers=headers,
    json={
        'command': 'flash',
        'line1': 'Pick Item',
        'line2': 'SKU-12345',
        'line3': 'Qty: 5'
    }
)

Barcode

Up to 23 characters can be encoded in a barcode. Barcodes are always placed at the bottom of the display. Barcodes less than 10 characters in length will scan more easily than longer barcodes.

If barcodes are combined with both an icon and a QR code, the maximum length is reduced to 15 characters. Barcodes are encoded in Code 128 B.

Two Ways to Specify Barcodes

You can specify barcodes using either line encoding or a convenience field:

session.post(
    url + "device/DEVICE_ID/",
    headers=headers,
    json={
        'command': 'flash',
        'line1': 'Pick Item A',
        'barcode': '12345Test'     # barcode as field
    }
)

QR Code

Like barcodes, 2-D QR codes can hold up to 23 characters. When specified, they always appear in the top left corner of the display. QR-Codes are encoded using Version 3.

Two Ways to Specify QR Codes

You can specify QR codes using either line encoding or a convenience field:

session.post(
    url + "device/DEVICE_ID/",
    headers=headers,
    json={
        'command': 'flash',
        'line1': 'Scan to verify',
        'qrcode': 'myspecialcode'   # QR code as field
    }
)

Icons (Arrows)

Icons are placed in the top left corner of the display (unless a QR-Code is also used, in which case they are placed in the bottom left corner).

Arrow Directions

session.post(
    url + "device/DEVICE_ID/",
    headers=headers,
    json={
        'command': 'flash',
        'arrow': 'up',            # arrow as field
        'line1': 'Pick Item',
        'line2': 'Shelf Above'
    }
)

Quantity

Quantity values are displayed in a large text box in the top left corner of the display. Values must be between 0 and 63.

session.post(
    url + "device/DEVICE_ID/",
    headers=headers,
    json={
        'command': 'flash',
        'line1': 'Pick Widget A',
        'quantity': 5              # displays "5" in quantity box
    }
)

Combined Example

You can combine multiple encoding types in a single command. Here's the same command using both methods:

session.post(
    url + "device/DEVICE_ID/",
    headers=headers,
    json={
        'command': 'flash',
        'arrow': 'up',               # arrow pointing up
        'line1': 'Pick Widget A',    # text
        'barcode': 'SKU12345',       # barcode
        'quantity': 3,               # quantity box
        'color': 'g',                # green LED
        'sound': '15,c5,4'          # beep pattern
    }
)

Encoding Reference Summary

Additional Icons (Hazard Signs)

In addition to arrows, devices support a full set of hazard and safety icons. These use the same \ic prefix followed by hazard and the icon character, or you can use the icon convenience field.

For example, hazardd or "icon": "hazardd" displays a "No Smoking" sign.

The complete icon reference is shown below with visual representations and their corresponding codes: