You can now use the M5Stack Core in ESPHome

The M5Stack Core is a modular, stackable, ESP32 board with a 2 inch LCD screen and three buttons, all in a package that doesn't look bad in your living room. ESPHome is a system to configure your ESP8266/ESP32 with YAML files to connect them to your home automation system (MQTT or Home Assistant). As of ESPHome 1.16.0, released this week, ESPHome supports the M5Stack Core's ILI9341 display.

What this means is that you can now set up your own display device without having to solder (thanks to the M5Stack Core's all-in-one package) and without having to program (thanks to ESPHome's configuration-based approach), and let it talk to your home automation system, including advanced functionality such as over-the-air (OTA) updates. This is really bringing do-it-yourself home automation to the masses.

For an example, have a look at my ESPHome configuration for the M5Stack PM2.5 Air Quality Kit. I wrote it two months ago for the dev version of ESPHome, and I can confirm that this now just works with the 1.16.0 release. The result looks like this:

/images/m5stack-air-quality-kit-esphome.jpg

Using the display

The display is using the SPI bus, so you define it like this with the right clock, MOSI and MISO pins:

spi:
  clk_pin: 18
  mosi_pin: 23
  miso_pin: 19

Then define a font: 1

# Download Roboto font from https://fonts.google.com/specimen/Roboto
font:
  - file: "fonts/Roboto-Medium.ttf"
    id: font_roboto_medium22
    size: 22
    glyphs: '!"%()+,-_.:°0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz/³µ'

Then you can define the display and add a lambda expression to show something on the screen:

display:
  - platform: ili9341
    id: m5stack_display
    model: M5Stack
    cs_pin: 14
    dc_pin: 27
    led_pin: 32
    reset_pin: 33
    rotation: 0
    lambda: |-
      Color RED(1,0,0);
      Color BLUE(0,0,1);
      Color WHITE(1,1,1);
      it.rectangle(0,  0, it.get_width(), it.get_height(), BLUE);
      it.rectangle(0, 22, it.get_width(), it.get_height(), BLUE);
      it.print(it.get_width() / 2, 11, id(font_roboto_medium22), RED, TextAlign::CENTER, "Particulate matter");

Using the buttons

The M5Stack Core's buttons were already supported: they can just be used as a binary sensor. For instance, this is how you use the middle button to toggle the display's backlight:

# Button to toggle the display backlight
binary_sensor:
  - platform: gpio
    id: M5_BtnB
    pin:
      number: 38
      inverted: true
    on_click:
      then:
        - switch.toggle: backlight

# GPIO pin of the display backlight
switch:
  - platform: gpio
    pin: 32
    name: "Backlight"
    id: backlight
    restore_mode: ALWAYS_ON

The M5Stack Core has three buttons. From left to right those are button A (GPIO39), button B (GPIO38) and button C (GPIO37). You can use them all like in the code above. As an exercise, I have reimplemented Homepoint's interface in ESPHome. With the left and right buttons I cycle through the pages showing sensor values of my home, and with the middle button I toggle the display backlight.

1

To be able to use fonts in ESPHome, you need to install Pillow with pip3 install pillow.