On Air illuminated Sign by Paladone

Modification of a Paladone On-Air Sign for Home Assistant automation, whilst maintaining the original control electronics and manual button.

Based on the instructable from WCBMaker - https://www.instructables.com/Browser-controlled-ON-AIR-Light-Modification/

Powered via the micro-USB connector at the rear of the unit, the LED circuit and the D1 Mini are wired to the 5v supply. The output of the GPIO pin on the D1 is switched high, through an NPN transistor to present a pulse to ground, imitating the button on the side of the unit. The normal operating conditions of the circuit are, with one press the lamp illuminates, another press and the lamp pulses and a third press will switch the light off.  The ESPHome code uses one pulse to turn the lamp on, and two further pulses to turn the lamp off.

Home Assistant is used to manually switch the lamp on and off, additionally a Web Hook is published to automate the On-Air Lamp via the Radio Shack PC Logging Software, Log4OM.

Parts Used

Wemos D1 Mini Microprocessor
Home Assistant
ESPHome Add-On
1 x 2n2222 Transistor
1 x 1K Ohm Resistor
1 x Veroboard
Connection Wire

Wiring Circuit

D1 Mini Code - ESPHome

esphome:
name: esphome-web-xxxxx
friendly_name: D1 Mini One
min_version: 2025.5.0
name_add_mac_suffix: false
on_boot:
then:
- switch.turn_off: LED_pin
- switch.turn_off: off_air

esp8266:
board: esp01_1m

# Enable logging
logger:

# Enable Home Assistant API
api:

# Allow Over-The-Air updates
ota:

- platform: esphome
wifi:
ssid: WIFI
password: WIFI_PASSWORD

# Optional manual IP
manual_ip:
static_ip: 192.168.xxx.xxx
gateway: 192.168.xxx.xxx
subnet: 255.255.255.0
dns1: 192.168.xxx.xxx
switch:

- platform: gpio
pin: GPIO5
id: LED_pin
on_turn_on:
- delay: 100ms
- switch.turn_off: LED_pin
internal: true

- platform: template
name: "On-Air"
id: lock_open
icon: "mdi:lock"
turn_on_action:
- switch.turn_on: LED_pin
- switch.turn_off: lock_open


- platform: template
name: "Off-Air"
id: off_air
icon: "mdi:lock-open-variant"
turn_on_action:
- switch.turn_on: LED_pin
- delay: 500ms
- switch.turn_on: LED_pin
- switch.turn_off: off_air