esphome-docs/components/qr_code.rst

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.. _display-qrcode:
QR Code Component
=================
.. seo::
:description: Instructions for displaying a QR Code in ESPHome
:image: qr-code.svg
Use this component to generate a QR-code containing a string on the device, which can then be drawn on compatible displays.
.. code-block:: yaml
qr_code:
- id: homepage_qr
value: esphome.io
Configuration variables:
------------------------
- **id** (**Required**, :ref:`config-id`): The ID with which you will be able to reference the QR-code later
in your display code.
- **value** (**Required**, string): The string which you want to encode in the QR-code.
- **ecc** (*Optional*, string): The error correction code level you want to use. Defaults to ``LOW``. You can use one of the following values:
- ``LOW``: The QR Code can tolerate about 7% erroneous codewords
- ``MEDIUM``: The QR Code can tolerate about 15% erroneous codewords
- ``QUARTILE``: The QR Code can tolerate about 25% erroneous codewords
- ``HIGH``: The QR Code can tolerate about 30% erroneous codewords
To draw the QR-code, call the ``it.qr_code`` function from your render lambda:
.. code-block:: yaml
display:
- platform: ...
# ...
pages:
- id: page1
lambda: |-
// Draw the QR-code at position [x=50,y=0] with white color and a 2x scale
it.qr_code(50, 0, id(homepage_qr), Color(255,255,255), 2);
// Draw the QR-code in the center of the screen with white color and a 2x scale
auto size = id(homepage_qr).get_size() * 2; // Multiply by scale
auto x = (it.get_width() / 2) - (size / 2);
auto y = (it.get_height() / 2) - (size / 2);
it.qr_code(x, y, id(homepage_qr), Color(255,255,255), 2);