The Idea

In a local shop I bought the cheapest (3.9 Euro) mechanical alarm clock I found, to scavenge the internal clock for this animated carousel.

However the casing was too nice not to be used in any other way.

So I decided to place an esp32-cam inside it with batteries, to be used as an extemporary webcam to watch kids, pets, cooking and so on at a distance.

The circuit

I composed the circuit using boards I had in my "wonder box", but they can be easily bought on AliExpress, EBay or Amazon.

Note the two 1 MOhm resistors, needed to reduce the battery voltage just to be measured by the ESP32 Analog to Digital Converter. 

The assembly

See the positioning of the devices. 

• The ESP32-cam board is fixed with some plastic foam glued to the chassis
• The TP4056 Battery Charger board has the USB charger socket back oriented
• The two batteries will be positioned on the bottom side of the case to lower the center of gravity.
• Bottom left there's a small optional antenna, found in an old WiFi router. 

Antenna (optional)

It can be easily built with a small piece of tin. See here the specifications.

Time

OK, I got a beautiful WiFi Camera but I lost the main function for a clock! Therefore, according to a friend of mine, I used a NeoPixel 12 RGB LEDs ring to recreate hours and minutes.

The EspHome is programmed to:

• Flash for 1 second the red LED indicating the hours
• Flash for 1 second the green LED indicating the minutes (0 5 10 15 20 25 30 35 40 45 50 55)
• Stay blank for 1 second
• (repeat)

ESPHome programming

The YAML code is the following 

esphome:
  name: esp32-cam
  friendly_name: ESP32-CAM
 

esp32:
  board: esp32dev
  framework:
    type: arduino

# Enable logging
logger:

# Enable Home Assistant API
api:

ota:

# Enable connection to my home hotspot
wifi:
  networks:
  - ssid: !secret wifi_ssid
    password: !secret wifi_password

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Esp32-Cam Fallback Hotspot"
    password: "Xy2wARLvmF24"

# Enable the WiFi info
text_sensor:
  - platform: wifi_info
    ip_address:
      name: ESP IP Address
    ssid:
      name: ESP Connected SSID
    bssid:
      name: ESP Connected BSSID
    mac_address:
      name: ESP Mac Wifi Address
    scan_results:
      name: ESP Latest Scan Results
    dns_address:
      name: ESP DNS Address


captive_portal:

# Enable SNTP server time synchronization
time:
  - platform: sntp
    id: sntp_time
    timezone: Europe/Rome

# enable the NeoPixel 12 LED's ring
display:
  - platform: addressable_light
    id: led_matrix_display
    addressable_light_id: light_ring
    width: 12
    height: 1
    update_interval: 1000ms
    lambda: |-
          // Define colors
          Color red = Color(0xFF0000);
          Color green = Color(0x00FF00);
          Color blue = Color(0x0000FF);
          Color black = Color(0x000000);
          // set timing to be repeated every 3 seconds
          int currentSeconds = id(sntp_time).now().second % 3;
          int currentPos;
          if(currentSeconds == 0){
                // flash hours
                currentPos = (id(sntp_time).now().hour + 12 - 4) % 12;
                it.line(currentPos,0,currentPos,0,red);             
          }else if (currentSeconds == 1){
                // flash minutes
                currentPos = id(sntp_time).now().minute/5;
                currentPos = (currentPos + 12 - 4) % 12;
                it.line(currentPos,0,currentPos,0,green);             
          }else{
                // clear everything
                it.line(0,0,0,0,black);             
          }
          

# Enable ESP32 camera
esp32_camera:
  external_clock:
    pin: GPIO0
    frequency: 20MHz
  i2c_pins:
    sda: GPIO26
    scl: GPIO27
  data_pins: [GPIO5, GPIO18, GPIO19, GPIO21, GPIO36, GPIO39, GPIO34, GPIO35]
  vsync_pin: GPIO25
  href_pin: GPIO23
  pixel_clock_pin: GPIO22
  power_down_pin: GPIO32

  # Image settings
  name: esp32-cam
  resolution: 1024x768
  jpeg_quality: 10
  #brightness: 1
  agc_gain_ceiling: 8X

# ESP32 Camera web server
esp32_camera_web_server:
  - port: 8080
    mode: stream
  - port: 8081
    mode: snapshot


sensor:
# Measure the battery voltage (3.7V nominal)
  - platform: adc
    pin: GPIO33
    name: "esp32-cam battery voltage"
    update_interval: 10s
    accuracy_decimals: 1
    attenuation: 11dB
    filters:
    - multiply: 2.0  # The voltage divider requires us to multiply by 2.0
 
  - platform: wifi_signal # Reports the WiFi signal strength/RSSI in dB
    name: "WiFi Signal dB"
    id: wifi_signal_db
    update_interval: 60s
    entity_category: "diagnostic"

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


# Turn on/off a green LED connected to GPIO13
switch:
  - platform: gpio
    pin: GPIO13
    id: gpio13_green_led
    name: "esp32-cam green led"
    
  - platform: gpio
    pin: GPIO4
    id: gpio4_bright_led
    name: "esp32-cam bright led"
    
# The 12 LEDs nepoixel ring
light:
  - id: light_ring
    platform: neopixelbus
    type: GRB
    variant: WS2812
    pin: GPIO12
    num_leds: "12"
    method: ESP32_I2S_1
    name: "NeoPixel Light"