The Nextion uses a baud rate of 9600 by default. It may be configured to use a faster speed by adding (for
example)
..code-block:: c++
baud=115200 // Sets the baud rate to 115200
bkcmd=0 // Tells the Nextion to not send responses on commands. This is the current default but can be set just in case
to the ``program.s`` source file (in the Nextion Editor) before the ``page`` line.
This permits faster communication with the Nextion display and it is highly recommended when using :ref:`uart-hardware_uarts`. Without a hardware uart make sure to set the baud rate to 9600.
The below example configures a UART for the Nextion display to use
See :ref:`display-nextion_lambda` for more information. This is typically empty. The individual components for the Nextion will handle almost all features needed for updating
-**on_setup** (*Optional*, :ref:`Action <config-action>`): An action to be performed after ESPHome connects to the Nextion. See :ref:`Nextion Automation <nextion-on_setup>`.
-**on_sleep** (*Optional*, :ref:`Action <config-action>`): An action to be performed when the Nextion goes to sleep. See :ref:`Nextion Automation <nextion-on_sleep>`.
-**on_wake** (*Optional*, :ref:`Action <config-action>`): An action to be performed when the Nextion wakes up. See :ref:`Nextion Automation <nextion-on_sleep>`.
-**on_page** (*Optional*, :ref:`Action <config-action>`): An action to be performed after a page change. See :ref:`Nextion Automation <nextion-on_page>`.
-**on_touch** (*Optional*, :ref:`Action <config-action>`): An action to be performed after a touch event (press or release). See :ref:`Nextion Automation <nextion-on_touch>`.
display updates. See the full :apiref:`nextion/nextion.h` for more info.
.._nextion_upload_tft:
-``upload_tft``: Start the upload process. See :ref:`nextion_upload_tft_file`
The developer tools in Home Assistant can be used to trigger the update. The below code block is an example on how to set this up.
..code-block:: yaml
api:
services:
- service: update_nextion
then:
- lambda: 'id(nextion1)->upload_tft();'
.._nextion_update_all_components:
-``update_all_components()``: All the components will publish their states.
..code-block:: c++
id(nextion1).update_all_components();
.._update_components_by_prefix:
-``update_components_by_prefix(std::string page)``: This will send the current state of any **component_name** matching the prefix. Some settings like background color need to be resent on page change. This is a good hook for that.
With Nextion displays, it's possible to define several automation actions. Depending on your setup, you may or may not need to use some of them.
.._nextion-on_setup:
``on_setup``
************
This automation will be triggered once ESP establishes a connection with Nextion. This happens after a boot up and may take some
noticeable time (e.g. hundreds of milliseconds) to establish a connection over UART. Typical use scenario for this automation is choosing of the initial
ap: {} # This spawns an AP with the device name and mac address with no password.
captive_portal:
display:
- platform: nextion
id: disp
on_setup:
then:
lambda: |-
// Check if WiFi hot-spot is configured
if (wifi::global_wifi_component->has_sta()) {
// Show the main page
id(disp).goto_page("main_page");
} else {
// Show WiFi Access Point QR code for captive portal, see https://qifi.org/
id(disp).goto_page("wifi_qr_page");
}
.._nextion-on_sleep:
``on_sleep / on_wake``
**********************
The action is called before and after Nextion goes to sleep mode. Nextion is not responsive while in sleep mode. Use these triggers to prepare your code
for that and :ref:`force-update <nextion_update_all_components>` the on-screen content once it's back.
.._nextion-on_page:
``on_page``
***********
This automation is triggered when a page is changed on the Nextion display. This includes both ESP and Nextion initiated page changes.
ESP initiates a page change by calling ``goto_page("page_name")`` or ``goto_page(page_id)`` function. Nextion can change pages as a reaction to user's activity (e.g. clicks) or using a timer.
In either case, this automation can be helpful to update on-screen controls for the newly displayed page.
If you fully own your Nextoin HMI design and follow the best practice of setting the components' vscope to global in the Nextion Editor, you'll probably never need this trigger.
However, if this is not the case and all / some of your UI components have local visibility scope, ``on_page`` will be your remedy. Here you can initiate updates of the relevant components.
Before actually updating components, you need to understand which page Nextion was switched to. ``x`` argument will contain a page id integer.
Once you know the page id, it's time to update the components. Two strategies would be possible. The first one is to use :ref:`Nextion Sensors <nextion_sensor>` for every UI field and use one of the
:ref:`update functions <nextion_update_all_components>`. The second is to manually set component text or value for each field:
..code-block:: yaml
on_page:
then:
lambda: |-
switch (x) {
case 0x02: // wifi_qr_page
// Manually trigger update for controls on page 0x02 here
This automation is triggered when a component is pressed or released on the Nextion display.
The following arguments will be available:
-``page_id``: Contains the id (integer) of the page where the touch happened.
-``component_id``: Contains the id (integer) of the component touched. It's required that the component have "Send Component ID" enabled either for "Touch Press Event" and/or "Touch Release Event".
-``touch_event``: It will be ``true`` for a "press" event, or ``false`` for a "release" event.
This will download the file from the tft_url and will transfer it over the UART to the Nextion.
Once completed both the ESP and Nextion will reboot. During the upload process esphome will be
unresponsive and no logging will take place. This uses the same protocol as the Nextion editor and
only updates the changes of the TFT file. If HTTPS/SSL is enabled it will be about 1kB/sec.
..warning::
If :ref:`uart-hardware_uarts` are not available then inconsistent results WILL occur. Lowering the speed to 9600 baud may help.
To host the TFT file you can use Home Assistant itself or any other web server. HTTPS, while always recommended on any network, will greatly reduce the upload speed.
Home Assistant
**************
To host the TFT file from Home Assistant, create a www directory if it doesn't exist in your config
directory. You can create a subdirectory for those files as well.
For example if the file is located
under your configuration directory ``www/tft/default.tft`` the URL to access it will be
The below NGINX example configuration will serve files out of the /var/www/nextion directory.
..code-block:: nginx
server {
listen 80;
access_log /var/log/nginx/nextion_access.log;
error_log /var/log/nginx/nextion_error.log;
root /var/www/nextion;
}
Components
----------
This library supports a few different components allowing communication back and forth from HA <-> MCU <-> Nextion.
..note::
If the Nextion is sleeping or if the component was set to be hidden, it will not update its components even if updates are sent.
After the Nextion wakes up, all components will send their states to the Nextion to get around this.
With the exception of the :doc:`../binary_sensor/nextion` that has the ``page_id``/``component_id`` options configured, the example below illustrates:
- Polling the Nextion for updates
- Dynamic updates sent from the Nextion to the ESP device
..code-block:: yaml
sensor:
- platform: nextion
nextion_id: nextion1
name: "n0"
component_name: n0
- platform: nextion
id: current_page
name: "current_page"
variable_name: dp
update_interval: 1s
Note that the first one requires a custom protocol to be included in the Nextion display's code/configuration. See the individual components for more detail.
