arduino_gauge_controller

A dedicated gauge controller for Arduinos.

Overview

This repository contains:

• Gaugecontroller/Gaugecontroller.ino: the Arduino Mega firmware for the stepper gauges, LEDs, and integrated HV5812-based VFD
• gaugecontroller.yaml: the ESPHome-based ESP32 firmware that exposes the gauges and VFD to Home Assistant via the native API

VFD Support

The integrated gauge controller now includes a 4-digit VFD with:

• 4 alphanumeric digits
• decimal point indicator
• alarm bell indicator

On the merged Arduino firmware, the HV5812 control pins are:

• D46 -> DATA
• D47 -> CLOCK
• D48 -> STROBE
• D49 -> BLANK/OE

The standalone VFD sketch used D51/D52/D53/D49, but 51/52/53 conflict with the gauge stepper pins in the integrated controller.

Arduino Serial Commands

The merged Arduino firmware accepts:

• VFD clears the display and turns off decimal point and alarm bell
• VFD 1234
• VFD 0123
• VFD DEAD
• VFD 8888.
• VFD BEEF!
• VFD 12AF.!

Rules:

• up to 4 characters are displayed
• valid characters are 0-9, A-F, and -
• . enables the decimal point
• ! enables the alarm bell
• shorter values are right-aligned
• leading zeroes are preserved if they are part of the input

Home Assistant Integration

The ESPHome firmware in gaugecontroller.yaml exposes entities to Home Assistant via the native API:

Gauge Controls

• Number entities for each gauge’s target value (with unit conversion)
• Number entities for speed and acceleration (diagnostic)
• Rezero buttons for each gauge and all gauges

VFD Display

• VFD Display: text entity for the displayed value
• VFD Decimal Point: switch entity
• VFD Alarm: switch entity

The display is intentionally exposed as a text entity rather than a numeric entity so that:

• leading zeroes are preserved
• hexadecimal values like DEAD or BEEF work
• clearing the display is possible with an empty value

LED Controls

• RGB light entity for each gauge’s backlight with effects (Blink, Breathe, Double Flash)
• Binary light entities for each gauge’s red/green indicators and status lights

Diagnostics

• WiFi signal sensor
• Uptime sensor
• IP address and SSID text sensors
• Arduino Last Message sensor