Integration 7-segment display max7219 in HA

ESPHome
1

Hello,

I have a 7 segment display max7219 connected to an ESP32. It seems that the wiring is right and the build is okay but I don’t know how to send text from homeassistant to the display.

I have used the following code at the end of the YAML but I don’t know how to call from homeassistant:

Example configuration entry

spi:
clk_pin: GPIO14
mosi_pin: GPIO15

display:

  • platform: max7219
    cs_pin: GPIO13
    num_chips: 1
    lambda: |-
    it.print(“01234567”);
2

Can try following:

text_sensor:
  - platform: template
    id: string_to_display
    name: String to Display

api:
  services:
    - service: string_publish
      variables:
        string_from_ha: string
      then:
        - lambda: |-
            id(string_to_display).publish_state(string_from_ha);

display:
  - platform: max7219
...
    lambda: |-
      it.printf("%s", id(string_to_display).state);

Then on HA side You can publish string by calling

service: esphome.<Your_device_name>_string_publish
data:
  string_from_ha: hello
1 Like
3

Thanks, the display works but parsing values from homeassistant not perfect, probably my own problem …

4

I can’t find the solution for parsing values to the display.

I use the following code:

---
substitutions:
  device_name: esphome-testkit
  device_description: "ESPHome testkit"
  device_key: "????"
  device_ota_pass: "???"

esphome:
  name: ${device_name}
  comment: "${device_description}"
  friendly_name: "${device_description}"

esp32:
  board: esp32dev
  framework:
    type: arduino

# Enable Home Assistant API
api:
  encryption:
    key: ${device_key}

  # Services t.b.v. MAX7219
  services:
    - service: string_publish
      variables:
        string_from_ha: string
      then:
        - lambda: |-
            id(string_to_display).publish_state(string_from_ha);

ota:
  password: ${device_ota_pass}

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
.
.
.
.
text_sensor:
      
  - platform: template
    id: string_to_display
    name: String to Display

spi:
  # t.b.v. MAX7219 sclk_pin en mosi_pin
  clk_pin: GPIO14
  mosi_pin: GPIO2

display:
  - platform: max7219
    cs_pin: GPIO13
    num_chips: 1
    lambda: |-
      it.printf("%s", id(string_to_display).state);

In Homeassistant I see that the state of ‘sensor.esphome_testkit_string_to_display’ is ‘123456’ but the display shows strange chars suct as ‘8.|8.p’.

Can somebody explain what is wrong?

Thanks!