A Go reimplementation of the RockPi SATA HAT fan and OLED controller.

• ✅ Dual PWM fan control (CPU + Disk fans)
• ✅ Linear temperature interpolation
• ✅ Separate temperature thresholds for CPU and disk fans
• ✅ Disk temperature monitoring via SMART
• ✅ Syslog support
• ✅ Inversed polarity support
• ✅ Minimum duty cycle threshold (7%)
• ✅ SSD1306 OLED display (128x32) with multi-font support
• ✅ Multiple display pages (system info, fan speed, disk usage, network I/O, disk I/O, disk temps)
• ✅ Configurable page cycling (5-second intervals)
• ✅ 180° display rotation support
• ✅ Button input handling (click/double-click/long-press)
• ✅ Configurable button actions (slider, switch, poweroff, reboot, custom commands)
• ✅ Environment file loading (/etc/rockpi-quad.env)

# Build the binary
cd rockpi-quad-go
GOOS=linux GOARCH=arm64 go build -o rockpi-quad-go ./cmd/rockpi-quad-go
# or 
make build

# Install on Rock Pi 4
sudo mkdir -p /usr/bin/rockpi-quad
sudo cp rockpi-quad-go /usr/bin/rockpi-quad/
sudo cp rockpi-quad-go.service /etc/systemd/system/
sudo systemctl daemon-reload
sudo systemctl enable rockpi-quad-go
sudo systemctl start rockpi-quad-go

# Check status
sudo systemctl status rockpi-quad-go

The application uses the same configuration files as the Python version:

• /etc/rockpi-quad.conf - Application settings
• /etc/rockpi-quad.env - Hardware/GPIO configuration

No changes to existing config files are needed.

go get github.com/d2r2/go-i2c
go get github.com/d2r2/go-logger
go get github.com/warthog618/go-gpiocdev
go get github.com/golang/freetype
go get gopkg.in/ini.v1
go get golang.org/x/image

Or simply:

go mod download

Or make deps

The application uses two configuration files:

Main configuration file (same format as Python version) containing:

• Fan temperature thresholds and PWM levels
• OLED display settings (rotation, temperature unit, enabled/disabled)
• Disk monitoring configuration (mount points for usage/I/O, temperature disks)
• Network interface configuration
  • skip_page (boolean): when true the Network I/O OLED page is disabled
• Key/button behavior settings (click, double-click, long-press actions)
• Timing settings for button detection

Example network configuration in /etc/rockpi-quad.conf to configure interfaces and skip the Network I/O page:

[network]
interfaces = eth0,wlan0
skip_page = true

Environment configuration file (same as Python version) containing hardware-specific settings:

• I2C pins for OLED (SDA, SCL, OLED_RESET)
• Button GPIO configuration
• Fan control GPIO settings
• SATA LED indicators
• PWM configuration

Note: Both files are shared with the Python version - no changes needed to switch between implementations.

The OLED displays the following information pages in rotation:

1. System Info Page 0: Uptime, CPU temperature, IP address
2. System Info Page 1: Fan speeds (CPU & Disk), CPU load, Memory usage
3. Disk Usage: Root partition and data disk usage percentages (sorted: sda, sdb, sdc, sdd)
4. Network I/O: RX/TX rates for configured network interfaces
5. Disk I/O: Read/Write rates for configured disks
6. Disk Temperatures: Temperature readings for SATA disks

Display features:

• Multi-font support: Uses DejaVu Sans Mono Bold TTF in sizes 10, 11, 12, and 14
• Proper Unicode: Supports degree symbol (°) and other special characters
• Two-column layout: Efficient use of 128x32 pixel display
• Auto-detection: Automatically detects SATA disks for temperature monitoring
• Configurable: Can be enabled/disabled, rotated 180°, and switch between Celsius/Fahrenheit

The button supports three types of presses with configurable actions:

• Single Click (click): Default action is slider (advance to next OLED page)
• Double Click (twice): Default action is switch (toggle fan on/off)
• Long Press (press): Default action is poweroff (system shutdown)

Configurable actions in /etc/rockpi-quad.conf:

[key]
click = slider      # Options: slider, switch, poweroff, reboot, none, or custom shell command
twice = switch
press = poweroff

Timing configuration:

[time]
twice = 0.7         # Double-click detection window (seconds)
press = 1.8         # Long-press threshold (seconds)

Note: Both files are shared with the Python version - no changes needed to switch between implementations.

The following environment variables are loaded from /etc/rockpi-quad.env:

OLED Display:

• SDA - I2C data pin (e.g., I2C7_SDA)
• SCL - I2C clock pin (e.g., I2C7_SCL)
• OLED_RESET - OLED reset GPIO (e.g., GPIO4_D2)

Button:

• BUTTON_CHIP - GPIO chip number
• BUTTON_LINE - GPIO line number

Fan Control:

• FAN_CHIP - GPIO chip for fan control
• FAN_LINE - GPIO line for fan control
• HARDWARE_PWM - Set to "1" to enable hardware PWM

PWM (when HARDWARE_PWM=1):

• PWM_CHIP - PWM chip device (default: pwmchip0)
• PWM_CPU_FAN - CPU fan PWM channel
• PWM_TB_FAN - Top/disk fan PWM channel
• POLARITY - PWM polarity (normal/inversed)

SATA LEDs:

• SATA_CHIP - GPIO chip for SATA LEDs
• SATA_LINE_1 - First SATA LED GPIO line
• SATA_LINE_2 - Second SATA LED GPIO line

• Lower memory footprint (~5MB vs ~30MB)
• Better CPU efficiency (compiled binary)
• Single binary deployment (no dependencies to install)
• No runtime dependencies (no Python interpreter needed)
• Faster startup time (no module loading)
• Built-in concurrency with goroutines
• Static typing catches errors at compile time

rockpi-quad-go/
├── cmd/
│   └── rockpi-quad-go/       # Main application entry point
│       └── main.go
├── internal/
│   ├── config/               # Configuration loading
│   │   └── config.go
│   ├── fan/                  # Fan control logic
│   │   └── fan.go
│   ├── button/               # Button input handling
│   │   └── button.go
│   ├── oled/                 # OLED display controller
│   │   ├── oled.go           # Display controller
│   │   ├── pages.go          # Page definitions and data
│   │   └── ssd1306.go        # SSD1306 I2C driver
│   └── disk/                 # Disk temperature monitoring
│       └── disk.go
├── pkg/
│   └── pwm/                  # PWM hardware interface
│       └── pwm.go
└── fonts/
    └── DejaVuSansMono-Bold.ttf  # TrueType font for OLED

The project includes comprehensive unit tests for core functionality:

# Run tests (macOS/Linux compatible tests only)
make test

# Run all tests (requires Linux environment)
make test-linux

# Run tests with coverage
go test -cover ./pkg/... ./internal/config

# Run specific package tests
go test -v ./pkg/pwm
go test -v ./internal/config

• pkg/pwm: PWM duty cycle calculation and sysfs operations
• internal/config: Configuration file loading and defaults
• internal/fan: Fan speed calculation (linear and non-linear modes)
• internal/button: Button event type handling
• internal/oled: Display rendering, page generation, and image rotation
• internal/disk: Device name parsing and temperature monitoring

Note: Some tests require a Linux environment with GPIO hardware support to run fully.

Same as the original Python version.