Good Day all,
Does anybody have an idea what I’m doing wrong? I’m trying to measure the battery voltage from out ESPHome, but the voltage I get is only 0.00000 V.
The TRMNL 7.5” (OG) DIY Kit has a XIAO-ESP32S3-Plus.
I also asked this question on the Seedstation forum, but not many people had an idea of what I can do.
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;'
