ESPHOME with 16x2 module does not display values anymore after reboot of ESP module

ESPHome
1

I programmed with ESPHome an ESP32 to display some Home Assistant sensor values on a 16x2 LCD module without using I2C adapter.
It works fine after ESPhome install and compile. But when I reboot the ESP32 module the display does not show values.
Although in the lESP32 log I see the the values are read and updated.
If I install the code again (wifi) it start displaying the values again.

esphome:
  name: esp32

esp32:
  board: esp32dev
  framework:
    type: arduino

# Enable logging
logger:

# Enable Home Assistant API
api:
  encryption:
    key: "******"

ota:
  password: "*****"

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


  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Esp32 Fallback Hotspot"
    password: "********"



captive_portal:


sensor:
  - platform: dht
    pin: 33
    temperature:
      name: TemperatureESP32
      id: temp
    humidity:
      name: "HumidityESP32"
      id: humidity
    update_interval: 60s
  - platform: homeassistant
    id: elek_up
    entity_id: sensor.dsmr_reading_electricity_currently_returned
  - platform: homeassistant
    id: elek_down
    entity_id: sensor.dsmr_reading_electricity_currently_delivered


display:
  - platform: lcd_gpio
    dimensions: 16x2
    data_pins:
      - 18
      - 17
      - 16
      - 21
    enable_pin: 23
    rs_pin: 19
    lambda: |-
      it.printf("%.1fC %.1f%%", id(temp).state, id(humidity).state);
      it.printf(1 , 1, "%.3fkW %.3fkW", id(elek_up).state, id(elek_down).state);

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2

Capture and post the startup logs for a reboot.

3

I am experiencing exactly same issue. My startup log is as follows:


[21:36:05][C][wifi:428]:   Local MAC: EC:64:C9:7C:F0:BC
[21:36:05][C][wifi:433]:   SSID: [redacted]
[21:36:05][C][wifi:436]:   IP Address: 192.168.1.12
[21:36:05][C][wifi:440]:   BSSID: [redacted]
[21:36:05][C][wifi:441]:   Hostname: 'esp32-co2--voc-sensor'
[21:36:05][C][wifi:443]:   Signal strength: -61 dB ▂▄▆█
[21:36:05][C][wifi:447]:   Channel: 11
[21:36:05][C][wifi:448]:   Subnet: XXX.XXX.XX.XX
[21:36:05][C][wifi:449]:   Gateway: XXX.XXX.X.X
[21:36:05][C][wifi:450]:   DNS1: XXX.XXX.XX.X
[21:36:05][C][wifi:451]:   DNS2: 0.0.0.0
[21:36:05][D][wifi:626]: Disabling AP...
[21:36:05][C][api:026]: Setting up Home Assistant API server...
[21:36:05][I][app:062]: setup() finished successfully!
[21:36:05][W][component:170]: Component wifi cleared Warning flag
[21:36:05][W][component:157]: Component api set Warning flag: unspecified
[21:36:05][I][app:100]: ESPHome version 2024.12.4 compiled on Feb  8 2025, 17:10:11
[21:36:05][C][wifi:600]: WiFi:
[21:36:05][C][wifi:428]:   Local MAC: XXXXXXXXXXXXXX
[21:36:05][C][wifi:433]:   SSID: [redacted]
[21:36:05][C][wifi:436]:   IP Address: XXX.XXX.XX.X
[21:36:05][C][wifi:440]:   BSSID: [redacted]
[21:36:05][C][wifi:441]:   Hostname: 'esp32-co2--voc-sensor'
[21:36:05][C][wifi:443]:   Signal strength: -61 dB ▂▄▆█
[21:36:05][C][wifi:447]:   Channel: 11
[21:36:05][C][wifi:448]:   Subnet: XXX.XXX.XX.XX
[21:36:05][C][wifi:449]:   Gateway: XXX.XXX.XX.X
[21:36:05][C][wifi:450]:   DNS1: XXX.XXX.XX.X
[21:36:05][C][wifi:451]:   DNS2: 0.0.0.0
[21:36:05][C][logger:185]: Logger:
[21:36:05][C][logger:186]:   Level: DEBUG
[21:36:05][C][logger:188]:   Log Baud Rate: 115200
[21:36:05][C][logger:189]:   Hardware UART: UART0
[21:36:05][C][i2c.arduino:071]: I2C Bus:
[21:36:05][C][i2c.arduino:072]:   SDA Pin: GPIO21
[21:36:05][C][i2c.arduino:073]:   SCL Pin: GPIO22
[21:36:05][C][i2c.arduino:074]:   Frequency: 50000 Hz
[21:36:05][C][i2c.arduino:086]:   Recovery: bus successfully recovered
[21:36:05][I][i2c.arduino:096]: Results from i2c bus scan:
[21:36:05][I][i2c.arduino:102]: Found i2c device at address 0x62
[21:36:05][C][scd4x:094]: scd4x:
[21:36:05][C][scd4x:095]:   Address: 0x62
[21:36:05][C][scd4x:112]:   Automatic self calibration: ON
[21:36:05][C][scd4x:121]:   Ambient pressure compensation disabled
[21:36:05][C][scd4x:122]:   Altitude compensation: 0m
[21:36:05][C][scd4x:127]:   Measurement mode: periodic (5s)
[21:36:05][C][scd4x:139]:   Temperature offset: 4.00 °C
[21:36:05][C][scd4x:140]:   Update Interval: 60.0s
[21:36:05][C][scd4x:141]:   CO2 'SCD41 CO2'
[21:36:05][C][scd4x:141]:     Device Class: 'carbon_dioxide'
[21:36:05][C][scd4x:141]:     State Class: 'measurement'
[21:36:05][C][scd4x:141]:     Unit of Measurement: 'ppm'
[21:36:05][C][scd4x:141]:     Accuracy Decimals: 0
[21:36:05][C][scd4x:141]:     Icon: 'mdi:molecule-co2'
[21:36:05][C][scd4x:142]:   Temperature 'SCD41 Temperature'
[21:36:05][C][scd4x:142]:     Device Class: 'temperature'
[21:36:05][C][scd4x:142]:     State Class: 'measurement'
[21:36:05][C][scd4x:142]:     Unit of Measurement: '°C'
[21:36:05][C][scd4x:142]:     Accuracy Decimals: 2
[21:36:05][C][scd4x:142]:     Icon: 'mdi:thermometer'
[21:36:05][C][scd4x:143]:   Humidity 'SCD41 Humidity'
[21:36:05][C][scd4x:143]:     Device Class: 'humidity'
[21:36:05][C][scd4x:143]:     State Class: 'measurement'
[21:36:05][C][scd4x:143]:     Unit of Measurement: '%'
[21:36:05][C][scd4x:143]:     Accuracy Decimals: 2
[21:36:05][C][scd4x:143]:     Icon: 'mdi:water-percent'
[21:36:05][C][lcd_gpio:027]: **GPIO LCD Display:**
**[21:36:05][C][lcd_gpio:028]:   Columns: 16, Rows: 2**
**[21:36:05][C][lcd_gpio:029]:   RS Pin: GPIO19**
**[21:36:05][C][lcd_gpio:031]:   Enable Pin: GPIO23**
**[21:36:05][C][lcd_gpio:033]:   Data Pin 0: GPIO18**
**[21:36:05][C][lcd_gpio:034]:   Data Pin 1: GPIO17**
**[21:36:05][C][lcd_gpio:035]:   Data Pin 2: GPIO16**
**[21:36:05][C][lcd_gpio:036]:   Data Pin 3: GPIO15**
**[21:36:05][C][lcd_gpio:043]:   Update Interval: 1.0s**
[21:36:05][D][api:103]: Accepted 192.168.1.84
[21:36:05][W][component:170]: Component api cleared Warning flag
[21:36:05][W][component:237]: Component api took a long time for an operation (51 ms).
[21:36:05][W][component:238]: Components should block for at most 30 ms.
[21:36:05][C][captive_portal:089]: Captive Portal:
[21:36:05][C][mdns:116]: mDNS:
[21:36:05][C][mdns:117]:   Hostname: esp32-co2--voc-sensor
[21:36:05][D][api.connection:1446]: Home Assistant 2025.2.1 XXX.XXX.XX.X: Connected successfully
[21:36:05][C][esphome.ota:073]: Over-The-Air updates:
[21:36:05][C][esphome.ota:074]:   Address: esp32-co2--voc-sensor.local:3232
[21:36:05][C][esphome.ota:075]:   Version: 2
[21:36:05][C][esphome.ota:078]:   Password configured
[21:36:05][C][safe_mode:018]: Safe Mode:
[21:36:05][C][safe_mode:020]:   Boot considered successful after 60 seconds
[21:36:05][C][safe_mode:021]:   Invoke after 10 boot attempts
[21:36:05][C][safe_mode:023]:   Remain in safe mode for 300 seconds
[21:36:05][C][api:140]: API Server:
[21:36:05][C][api:141]:   Address: esp32-co2--voc-sensor.local:6053
[21:36:05][C][api:143]:   Using noise encryption: YES

Any hint would be appreciated…

TIA. J

4

How are you rebooting the ESP? Maybe a full power cycle solves the problem.

5

Basically the lcd stops working after the power cycle. I need to re-flash it and then it works.

6

I have the same setup (ESP32 + display_gpio) and similar problem. My display does not show any text. However, this happens randomly. Like 50% of times. It does not matter if I use soft or hard reset button or cut the power. Tried many wannabe solutions (excluded software and hardware parts, changed display, …) but nothing changes.
I am willing to post log file. However, it is normal. No errors whatsoever.
Any hints?