Supported Targets	ESP32	ESP32-C2	ESP32-C3	ESP32-C6	ESP32-H2	ESP32-P4	ESP32-S2	ESP32-S3

ESP32 Clocks (ESP-IDF)

It connects to the Wi-Fi and syncs the time with the NTP server, showing the time and temperature on the screen. Optionally saving it to the external timer and showing the temperature from the sensor + from the API. Supports OTA Wi-Fi updates.

The project started from the dead section of the built-in clocks in my bath mirror and moved to my first experience with microcontrollers, C language and creating the home "lab".

(green wires - data, yellow wires - clock, blue wire - low / high light sensor output)

Features

• Based on ESP32 microcontroller (tested with ESP32, ESP32C3 and ESP32S3). I've used the WeActStudio ESP32-C3FH4 Core Board.

• TM1637 7-segment display.

• Optional: NTP Sync

• Optional: DS3231 external timer. Saving time to the separate precise clocks.

• Optional: SHT3X environment sensor. Measuring temperature (and optionally humidity).

• Optional: BMP280/BME280 environment sensor. Measuring temperature (and optionally humidity).

• Optional: DS1820 temperature sensor. Measuring temperature.

• Optional: Temperature from API over Wi-Fi and HTTPS. api.weatherapi.com

• Optional: OTA Updates over Wi-Fi and HTTPS.

• Optional: GL5516 Photo resistor. Switching between full and minimal brightness using ADC.

• Optional: HW-072 Light Sensor. Switching between full and minimal brightness based on the photoresistor output (both analog and digital).

Requirements

The project was created using ESP-IDF plugin for Visual Studio Code and ESP-IDF-LIB.

Initial setup

1. Clone the repo git clone git@github.com:Flight/clocks.git and go inside: cd clocks.

2. Generate the certificate for weatherapi.com

   echo -n | openssl s_client -connect 192.168.50.100:443 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > main/weather_from_api/api_weatherapi_com.pem

3. Generate a certificate for the OTA Updates. Please don't forget to fill the server name on this step:

   Common Name (e.g. server FQDN or YOUR name) []: 192.168.50.100 (your local IP address).

   openssl req -newkey rsa:2048 -new -nodes -x509 -days 365 -keyout ota_server/key.pem -out main/ota_update/cert.pem

4. Change the settings.

Run the project

Run the project using the ESP-IDF Build, Flash and Monitor button (number 6 on the screenshot).

OTA Wi-Fi Updates

Initial Checklist

• Flash size according to the settings on the screenshot (> 4 MB is needed for OTA).
• Partition table in settings
• Firmware upgrade endpoint URL in the Clocks OTA Update section.
• Generated the certificate main/ota_update/cert.pem.

Run OTA Update

1. Create new GIT Tag

   git tag -a v0.0.1 -m "new release"

   git push origin v0.0.1 (optional)

2. Run OTA web-server from ota_server folder. I'm using this http-server as OpenSSL one didn't work properly and was hanging during download until you don't stop it manually.

   cd ota_server

   sudo npx http-server -S -C ../main/ota_update/cert.pem -p 8070 -c-1

3. Drop the file clocks.bin to ota_server folder or setup the build to generate the output file in that folder.

   You can find the main.bin in the build folder after you built it. Just copy and rename it to clocks.bin.

4. Restart the ESP32. It will automatically start update process in 10 seconds after boot.

Next steps

• Replace the light sensor with the one which supports dead-zone to prevent blinking when the light is near the threshold. (Done)
• Compare OTA versions to prevent cycle update. (Done)
• Replace the Legacy ADC lib with adc_oneshot.h as ESP-IDF suggests.
• Show if it would be rainy on the display.
• Web server with ESP_LOG outputs. The device already supports OTA Wi-Fi updates, so it will make it even easier.
• Check updates from FTP server or Samba directly from the router.
• Rewrite TM1637 lib as it isn't perfect.
• Add the human presense sensor like LD2410 and turn off the screen if there is nobody in the bath to prevent display degradation. Maybe can add some other cool features with it.

More photos

Folder contents

The project clocks contains the entry point file in C language main.c. The file is located in folder main.

ESP-IDF projects are built using CMake. The project build configuration is contained in CMakeLists.txt files that provide set of directives and instructions describing the project's source files and targets (executable, library, or both).

Below is short explanation of remaining files in the project folder.

├── CMakeLists.txt
├── main
│   ├── CMakeLists.txt
│   └── main.c
└── README.md