TRMNL 7.5" (OG) DIY Kit Battry voltage status not wokring

Good Day all,

Does anybody have an idea what I’m doing wrong? I’m trying to measure the battery voltage, but the voltage I get is only 0.00000 V.

I followed the example script from this page and take out what i only need from my understanding.

this is output from ESPHome:

INFO ESPHome 2025.10.3
INFO Reading configuration /config/esphome/einkdisplay.yaml...
INFO Detected timezone 'Europe/Amsterdam'
INFO Starting log output from einkdisplay.local using esphome API
INFO Successfully resolved einkdisplay.local in 0.005s
WARNING Can't connect to ESPHome API for einkdisplay.local: Error connecting to [AddrInfo(family=<AddressFamily.AF_INET: 2>, type=<SocketKind.SOCK_STREAM: 1>, proto=6, sockaddr=IPv4Sockaddr(address='192.168.1.109', port=6053))]: [Errno 113] Connect call failed ('192.168.1.109', 6053) (SocketAPIError)
INFO Trying to connect to einkdisplay.local in the background
INFO Successfully connected to einkdisplay @ 192.168.1.109 in 0.013s
INFO Successful handshake with einkdisplay @ 192.168.1.109 in 0.108s
[22:35:37.299][I][app:185]: ESPHome version 2025.10.3 compiled on Oct 24 2025, 22:13:53
[22:35:37.299][C][wifi:679]: WiFi:
[22:35:37.299][C][wifi:458]:   Local MAC: D0:CF:00:00:ED:24
[22:35:37.305][C][wifi:465]:   IP Address: 192.168.1.109
[22:35:37.320][C][wifi:469]:   SSID: [redacted]
[22:35:37.320][C][wifi:469]:   BSSID: [redacted]
[22:35:37.320][C][wifi:469]:   Hostname: 'einkdisplay'
[22:35:37.320][C][wifi:469]:   Signal strength: -73 dB ▂▄▆█
[22:35:37.320][C][wifi:469]:   Channel: 11
[22:35:37.320][C][wifi:469]:   Subnet: 255.255.255.0
[22:35:37.320][C][wifi:469]:   Gateway: 192.168.1.1
[22:35:37.320][C][wifi:469]:   DNS1: 192.168.1.1
[22:35:37.320][C][wifi:469]:   DNS2: 0.0.0.0
[22:35:37.320][C][logger:261]: Logger:
[22:35:37.320][C][logger:261]:   Max Level: DEBUG
[22:35:37.320][C][logger:261]:   Initial Level: DEBUG
[22:35:37.320][C][logger:267]:   Log Baud Rate: 115200
[22:35:37.320][C][logger:267]:   Hardware UART: USB_SERIAL_JTAG
[22:35:37.320][C][logger:274]:   Task Log Buffer Size: 768
[22:35:37.334][C][spi:067]: SPI bus:
[22:35:37.334][C][spi:068]:   CLK Pin: GPIO7
[22:35:37.334][C][spi:069]:   SDI Pin: 
[22:35:37.334][C][spi:070]:   SDO Pin: GPIO9
[22:35:37.340][C][spi:075]:   Using HW SPI: SPI
[22:35:37.379][C][uptime.sensor:015]: Uptime Sensor 'Uptime'
[22:35:37.379][C][uptime.sensor:015]:   State Class: 'total_increasing'
[22:35:37.379][C][uptime.sensor:015]:   Unit of Measurement: 's'
[22:35:37.379][C][uptime.sensor:015]:   Accuracy Decimals: 0
[22:35:37.380][C][uptime.sensor:025]:   Device Class: 'duration'
[22:35:37.384][C][uptime.sensor:029]:   Icon: 'mdi:timer-outline'
[22:35:37.385][C][uptime.sensor:033]:   Type: Seconds
[22:35:37.399][C][template.sensor:015]: Template Sensor 'Display Last Update'
[22:35:37.399][C][template.sensor:015]:   State Class: ''
[22:35:37.399][C][template.sensor:015]:   Unit of Measurement: ''
[22:35:37.399][C][template.sensor:015]:   Accuracy Decimals: 1
[22:35:37.400][C][template.sensor:025]:   Device Class: 'timestamp'
[22:35:37.400][C][template.sensor:362]:   Update Interval: 60.0s
[22:35:37.414][C][template.sensor:015]: Template Sensor 'Display Refresh Count'
[22:35:37.414][C][template.sensor:015]:   State Class: 'total_increasing'
[22:35:37.414][C][template.sensor:015]:   Unit of Measurement: 'Refreshes'
[22:35:37.414][C][template.sensor:015]:   Accuracy Decimals: 0
[22:35:37.415][C][template.sensor:362]:   Update Interval: 60.0s
[22:35:37.449][C][homeassistant.time:010]: Home Assistant Time:
[22:35:37.449][C][homeassistant.time:010]:   Timezone: 'CET-1CEST,M3.5.0,M10.5.0/3'
[22:35:37.455][C][adc.esp32:015]: ADC Sensor 'Battery Voltage'
[22:35:37.455][C][adc.esp32:015]:   State Class: 'measurement'
[22:35:37.455][C][adc.esp32:015]:   Unit of Measurement: 'V'
[22:35:37.455][C][adc.esp32:015]:   Accuracy Decimals: 2
[22:35:37.461][C][adc.esp32:025]:   Device Class: 'voltage'
[22:35:37.461][C][adc.esp32:122]:   Pin: GPIO1
[22:35:37.464][C][adc.esp32:123]:   Channel:       0
[22:35:37.464][C][adc.esp32:123]:   Unit:          ADC1
[22:35:37.464][C][adc.esp32:123]:   Attenuation:   12 dB
[22:35:37.464][C][adc.esp32:123]:   Samples:       1
[22:35:37.464][C][adc.esp32:123]:   Sampling mode: average
[22:35:37.468][C][adc.esp32:133]:   Setup Status:
[22:35:37.468][C][adc.esp32:133]:     Handle Init:  OK
[22:

This .yaml i created:

esphome:
  name: einkdisplay
  friendly_name: EinkDisplay

esp32:
  board: esp32-s3-devkitc-1
  framework:
    type: arduino

# Enable logging
logger:

# Enable Home Assistant API
api:
  encryption:
    key: "KZfSEtCJbvI2000000000000000000e0LUu9Ih1b2BU="

ota:
  - platform: esphome
    password: "b62c4d1a00000000000000007b4e464d364"

globals:
  - id: wifi_status
    type: int
    restore_value: no
    initial_value: "0"
  - id: recorded_display_refresh
    type: int
    restore_value: yes
    initial_value: '0'
    
wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password
  on_connect:
    then:
      - lambda: |-
          id(wifi_status) = 1;
  on_disconnect:
    then:
      - lambda: |-
          id(wifi_status) = 0;

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Einkdisplay Fallback Hotspot"
    password: "OReBfmKer3EX"

captive_portal:

# Here is deep sleep part
deep_sleep:
  id: deep_sleep_1
  run_duration: 1min  # Device wake up and run 60s (enough to pull data and update)
  sleep_duration: 60min  # deep sleep for 120m

http_request:
  verify_ssl: false
  timeout: 10s
  watchdog_timeout: 15s

online_image:
  - id: dashboard_image
    format: bmp
    type: BINARY
    buffer_size: 50000
    url: http://192.168.1.113:10000/dashboard-display?viewport=800x480&eink=2&invert&format=bmp #change this link to your screenshot link
    update_interval: 25s
    on_download_finished:
      - delay: 0ms
      - component.update: main_display

spi:
  clk_pin: GPIO7
  mosi_pin: GPIO9

display:
  - platform: waveshare_epaper
    id: main_display
    model: 7.50inv2
    cs_pin: GPIO44
    dc_pin: GPIO10
    reset_pin: GPIO38
    busy_pin: 
      number: GPIO4
      inverted: true
    update_interval: never
    lambda: |-
      it.image(0, 0, id(dashboard_image));
      
time:
  - platform: homeassistant
    id: homeassistant_time
          
sensor:

  - platform: adc
    pin: GPIO1
    name: "Battery Voltage"
    id: battery_voltage
    update_interval: 60s
    attenuation: 12db
    filters:
      - multiply: 2.0
  
  - platform: wifi_signal # Reports the WiFi signal strength/RSSI in dB
    name: "WiFi Signal dB"
    id: wifi_signal_db
    update_interval: 120s
    entity_category: "diagnostic"

  - platform: copy # Reports the WiFi signal strength in %
    source_id: wifi_signal_db
    name: "WiFi Signal Percent"
    id: wifi_signal_percent
    filters:
      - lambda: return min(max(2 * (x + 100.0), 0.0), 100.0);
    unit_of_measurement: "Signal %"
    entity_category: "diagnostic"

  - platform: uptime
    name: Uptime

  - platform: internal_temperature
    name: "Internal Temperature"

  - platform: template
    name: "Display Last Update"
    device_class: timestamp
    entity_category: "diagnostic"
    id: display_last_update
    lambda: 'return id(homeassistant_time).now().timestamp;'

  - platform: template
    name: "Display Refresh Count"
    accuracy_decimals: 0
    unit_of_measurement: "Refreshes"
    state_class: "total_increasing"
    entity_category: "diagnostic"
    lambda: 'return id(recorded_display_refresh) += 1;'