Into The Void

Daysync - An ESP32 based smart screen for your desk

A low power smart display for your desk with news, weather, crypto, stocks and other information

Published on Apr 17 2025 at 3:32pm

Overview

Daysync combines an ESP32 microcontroller with a TFT display (ESP32-2432S028R) to create a smart information display system. It fetches and displays various types of data including weather information, MotoGP and Formula 1 race calendars, cryptocurrency prices, stock market data and news headlines.

graph LR
    subgraph ESP32["ESP32 Display"]
        E[ESP32 Board]
        T[TFT Display]
        E --> T
    end

    subgraph Backend["Go Backend"]
        B[API Server]
        W[Weather API]
        M[MotoGP API]
        F[F1 API]
        C[Crypto API]
        N[News API]
        S[Stock API]
    end

    E <-->|HTTP Requests| B
    B <-->|Data Fetch| W
    B <-->|Data Fetch| M
    B <-->|Data Fetch| F
    B <-->|Data Fetch| C
    B <-->|Data Fetch| N
    B <-->|Data Fetch| S

Parts

ESP32-2432S028R with 2.4” TFT Display

These boards are cheap and easy to find on AliExpress. You can find them here.

3D Printed Enclosure

I designed a 3D printed enclosure using the free version of Autodesk Fusion 360 for the ESP32-2432S028R with 2.4” TFT Display. This was quite time consuming and I had to use Vernier Callipers to get accurate measurements. At the end of it, the result was better than I expected. I used a Bambu Labs P1S printer to print the enclosure. I even managed to get a cool bindok logo etched at the back of the enclosure.

bindok meaning no brains is my gamer alias 🤣

You can download the STL file here

Other Parts

• Micro USB Cable for programming the ESP32
• USB power (any cheap 5V adaptor)
• USB-C to micro usb adaptor if your PC only has USB-C ports
• Vernier Callipers for measuring the dimensions of the board

Source Code

The source code is available on GitHub.

System Architecture

The project consists of two main components:

1. ESP32 Display System

   • ESP32 microcontroller
   • TFT display
   • WiFi connectivity
   • LVGL for UI rendering

2. Go Backend Server

   • RESTful API endpoints
   • Data caching
   • External API integration
   • Configuration management

graph TD
    subgraph ESP32["ESP32 System"]
        W[WiFi Module]
        M[Memory]
        D[Display Driver]
        W --> M
        M --> D
    end

    subgraph Backend["Backend Services"]
        C[Cache Layer]
        A[API Layer]
        E[External APIs]
        C --> A
        A --> E
    end

    ESP32 <-->|HTTP| Backend

Backend Functionality

API Endpoints

The Go backend provides several RESTful endpoints:

graph TD
    API[API Server] --> MotoGP[MotoGP Endpoints]
    API --> F1[F1 Endpoints]
    API --> Weather[Weather Endpoint]
    API --> Crypto[Crypto Endpoint]
    API --> News[News Endpoint]
    API --> Finance[Finance Endpoint]

    MotoGP --> |/api/motogp| SeasonData
    MotoGP --> |/api/motogpnextrace| NextRace
    F1 --> |/api/formula1| SeasonData
    F1 --> |/api/formula1nextrace| NextRace
    Weather --> |/api/weather| LocationData
    Crypto --> |/api/crypto| PriceData
    News --> |/api/news| Headlines
    Finance --> |/api/finance| StockData

Data Flow

sequenceDiagram
    participant ESP32
    participant Backend
    participant ExternalAPI

    ESP32->>Backend: HTTP Request
    Backend->>Backend: Check Cache
    alt Cache Hit
        Backend-->>ESP32: Return Cached Data
    else Cache Miss
        Backend->>ExternalAPI: Fetch New Data
        ExternalAPI-->>Backend: Return Data
        Backend->>Backend: Update Cache
        Backend-->>ESP32: Return Fresh Data
    end

ESP32 Display Features

Screen Management

The ESP32 display automatically cycles through different information screens:

stateDiagram-v2
    [*] --> Weather
    Weather --> MotoGP
    MotoGP --> Formula1
    Formula1 --> StockMarket
    StockMarket --> Cryptocurrency
    Cryptocurrency --> News1
    News1 --> News2
    News2 --> About
    About --> Weather

Data Display

Each screen type has specific information layout:

graph TD
    subgraph Weather["Weather Screen"]
        W1[Location]
        W2[Date/Time]
        W3[Temperature]
        W4[Humidity]
        W5[Conditions]
    end

    subgraph Racing["Race Calendar Screen"]
        R1[Race Name]
        R2[Circuit]
        R3[Date]
        R4[Next Race Info]
    end

    subgraph Finance["Financial Screen"]
        F1[Symbol]
        F2[Current Price]
        F3[Price Change]
        F4[Market Data]
    end

Technical Implementation

Backend Features

1. Caching System

   • 60-minute cache duration
   • Memory-efficient storage
   • Automatic cache invalidation

2. API Integration

   • RESTful endpoints
   • Error handling
   • Rate limiting
   • CORS support

3. Configuration Management

   • YAML configuration
   • Environment variables
   • Test mode support

ESP32 Features

1. Display Management

   • LVGL for UI
   • Screen rotation
   • Automatic updates (Server side, microcontroller auto updates not supported)
   • Error handling

2. Data Processing

   • JSON parsing
   • Data validation
   • Error recovery
   • WiFi reconnection

Development and Testing

The project includes several development features:

graph LR
    subgraph Dev["Development Tools"]
        T[Test Mode]
        C[Cache Control]
        D[Debug Logging]
        M[Mock Data]
    end

    subgraph Test["Testing Features"]
        U[Unit Tests]
        I[Integration Tests]
        E[Error Simulation]
        P[Performance Tests]
    end

Possible Future Enhancements

1. Planned Features
   • Ability for user to change their wifi SSID and password (harcoded at the moment)
   • Custom screen layouts
   • User preferences
   • More data sources
   • Offline mode
   • Automatic OTA updates

This was a fun project that taught me how to use a low power microcontroller to display information. The ESP32 only makes REST calls, the heavy lifting is done by the Go backend. By combining the power of ESP32 with a Go backend, it provides a flexible way to display various types of real-time data.

There can be many improvements to enhance the user experience. User preferences via a web interface would be great. I’ll hopefully find time to keep improving this project and make it more user friendly.

Tags: golang , c++ , programming , electronics , iot