HW Monitor

A hardware monitoring display project for ESP32-C3 that shows CPU and GPU metrics on a ST7789 TFT display using LVGL graphics library.

Overview

Real-time hardware monitor with three circular gauge widgets displaying:

• CPU Temperature (left gauge)
• CPU Load (center gauge)
• GPU Temperature (right gauge)

The gauges feature color-coded zones that change based on the monitored values, providing quick visual feedback on system status.

Hardware Requirements

• ESP32-C3 SuperMini
• ST7789 TFT Display (76x284 pixels)
• Serial connection to host PC for data input

Pin Configuration (user defined)

Function	GPIO Pin
TFT CS	10
TFT RST	8
TFT DC	9
TFT MOSI	7
TFT SCLK	6
TFT BL	20

Software Dependencies

• PlatformIO - Build system and IDE
• Arduino Framework - ESP32 Arduino core
• LVGL - Light and Versatile Graphics Library for embedded displays
• LovyanGFX - Fast graphics library for various display controllers

Features

Color-Coded Zones

Temperature Gauges (CPU & GPU) (user defined)

• 🔵 Blue: < 35°C (Cool)
• 🟢 Green: 35-55°C (Normal)
• 🟠 Orange: 55-75°C (Warm)
• 🔴 Red: 75-100°C (Hot)

Load Gauge (CPU) (user defined)

• 🔵 Blue: < 40% (Low)
• 🟢 Green: 40-60% (Normal)
• 🟠 Orange: 60-80% (High)
• 🔴 Red: 80-100% (Critical)

Display Layout

┌──────────────────────────────────────┐
│  [CPU Temp]  [CPU Load]  [GPU Temp]  │
│     °C          %           °C       │
└──────────────────────────────────────┘

Serial Communication Protocol

The device expects data via serial port at 115200 baud in the following format:

<cpu_temp>,<cpu_load>,<gpu_temp>\n

Example

45,60,55

This would set:

• CPU Temperature: 45°C
• CPU Load: 60%
• GPU Temperature: 55°C

Building and Uploading

Using PlatformIO CLI

# Build the project
pio run

# Upload to device
pio run --target upload

# Monitor serial output
pio device monitor

Using PlatformIO IDE (VS Code)

1. Open the project folder in VS Code
2. Use the PlatformIO toolbar:
   • Click "Build" to compile
   • Click "Upload" to flash the device
   • Click "Serial Monitor" to view output

Configuration

Display Configuration

The display is configured in include/display.hpp using LovyanGFX with the following settings:

• Resolution: 284x76 pixels
• SPI Mode: 0
• Write frequency: 40 MHz
• Read frequency: 16 MHz

Scale Ranges

Modify these values in src/main.cpp to adjust gauge ranges:

// Temperature scale
static int32_t scale_temperature_min = 20;
static int32_t scale_temperature_max = 100;

// Load scale
static int32_t scale_load_min = 0;
static int32_t scale_load_max = 100;

Zone Thresholds

Adjust color zone transitions:

// Temperature zones
static int32_t zone1_temperature =  35;
static int32_t zone2_temperature =  55;
static int32_t zone3_temperature =  75;
static int32_t zone4_temperature = 100;

// Load zones
static int32_t zone1_load =  40;
static int32_t zone2_load =  60;
static int32_t zone3_load =  80;
static int32_t zone4_load = 100;

Project Structure

HW Monitor/
├── platformio.ini          # PlatformIO configuration
├── include/
│   ├── display.hpp         # LovyanGFX display driver configuration
│   ├── pin_config.h        # Pin definitions for TFT display
│   └── lv_conf.h          # LVGL configuration
├── src/
    └── main.cpp           # Main application code

Host PC Integration

see python-daemon dir

Troubleshooting

Display not working

• Check pin connections match pin_config.h
• Verify backlight is connected to GPIO 20
• Ensure power supply is adequate (5V/1A minimum)

No serial data received

• Verify baud rate is set to 115200
• Check USB cable supports data (not charge-only)
• Confirm correct COM port is selected

Gauges not updating

• Check serial data format matches: <int>,<int>,<int>\n
• Ensure values are within configured ranges
• Monitor serial output for parsing errors

License

This project is provided as-is for educational and personal use.

Acknowledgments

• Built with PlatformIO
• Graphics powered by LVGL
• Display driver by LovyanGFX