AnalogGaugeUSB

AnalogGaugeUSB is a DIY hardware project that brings the retro charm of analog gauges to your modern PC setup. It uses a Raspberry Pi Pico to drive physical needles and RGB lighting, displaying real-time CPU and GPU load information from your Windows computer.

Features

• Real-time Monitoring: Displays CPU and GPU usage (0-100%) on two separate analog gauges.
• RGB Lighting: extensive RGB backlight support for customizable aesthetics (CPU and GPU sides, left and right).
• USB HID Interface: Driverless plug-and-play connection using standard Human Interface Device (HID) protocol.
• Easy Debugging: SWD pins are accessible on the back side of the enclosure for easy firmware debugging.
• Windows Service: Background service runs automatically to fetch sensor data and update the display.
• 3D Printable Enclosure: Complete files included for printing a custom case.

Hardware Architecture

Components

• Microcontroller: Raspberry Pi Pico (RP2040)
• Display: 3V Analog Voltmeters
• Lighting: Common Anode RGB LEDs
  • Red Cathode: 100Ω resistor
  • Green Cathode: 10Ω resistor
  • Blue Cathode: 10Ω resistor
• Connection: USB (Micro-USB to PC)

Pinout (Raspberry Pi Pico)

Component	Function	GPIO Pin
CPU Gauge	Needle (PWM)	GP10
GPU Gauge	Needle (PWM)	GP6
GPU Right LED	Blue / Green / Red	GP0 / GP1 / GP2
GPU Left LED	Blue / Green / Red	GP3 / GP4 / GP5
CPU Right LED	Blue / Green / Red	GP7 / GP8 / GP9
CPU Left LED	Blue / Green / Red	GP11 / GP12 / GP13

Software Architecture

Firmware

The firmware is written in C using the Pico SDK and TinyUSB. It enumerates as a USB HID device.

• VID: 0x6D6F
• PID: 0x1004
• Report ID: 1

It receives 3-byte reports to control the hardware:

1. Report ID (0x01)
2. Component ID (0=CPU Needle, 1=GPU Needle, 2-13=LED channels)
3. Value (0-255)

Host Service

The Windows host application is a .NET 10.0 Worker Service.

• Uses LibreHardwareMonitor to fetch cpu and gpu load sensors.
• Uses HidSharp to communicate with the USB device.
• Installs as a Windows Service to run silently in the background.

Getting Started

Prerequisites

• Firmware: CMake, ARM GCC Toolchain (for Pico development).
• Software: .NET 10.0 SDK.
• Hardware: 3D Printer (for enclosure), Soldering iron, Wires.

1. Build & Flash Firmware

1. Navigate to the firmware directory.
2. Create a build directory:

   mkdir build
   cd build

3. Configure and build:

   cmake ..
   make

4. Hold the BOOTSEL button on your Pico and plug it in.
5. Copy the generated .uf2 file to the RPI-RP2 drive.

2. Build & Install Service

1. Navigate to the service directory.
2. Publish the project:

   dotnet publish -c Release -r win-x64 -o publish

3. Run the installation script (requires Admin privileges):

   install.bat

   Alternatively, manually create the service using sc create "Analog Gauge USB" binPath= "..."

3. Enclosure

1. Open enclosure/AnalogGaugeUSB v6.f3d in Fusion 360 or use the provided .stl files.
2. Print the parts:
   • AnalogGaugeUSB-front.stl
   • AnalogGaugeUSB-back.stl
   • AnalogGaugeUSB-inside1.stl, inside2.stl, inside3.stl
3. Assemble the gauges and LEDs into the case and wire them to the Pico according to the pinout.

License

This project is licensed under the MIT License - see the LICENSE file for details.