Landy Gauge

Contact

Thu, 23 Apr 2026 00:00:00 +0000

If you have questions about the Landy Gauge project, found a bug, or want to contribute, feel free to get in touch.

Email: paulrbarnard@mac.com

You can also open an issue or pull request directly on the GitHub repository.

Why I did it

Tue, 21 Apr 2026 00:00:00 +0000

The reasoning behind the project and the motivations for open sourcing the project

About

Mon, 20 Apr 2026 00:00:00 +0000

What is the Landy Gauge?

The Landy Gauge is a 52mm standard vehicle instrument gauge. It is an open-source project built around the Waveshare ESP32-S3 1.85" round LCD module. Originally designed for my Land Rover Defender, it’s adaptable to any vehicle.

It packs a surprising number of features into a compact round display:

Compass — digital compass with vehicle heading and bearing
Inclinometer — pitch with customisable Landrover image
Tyre Pressures — BLE TPMS sensor monitoring for up to 4 tyres
Exhaust Gas Temperature — thermocouple-based EGT monitoring
Boost Pressure — MAP sensor-based turbo boost gauge
Clock — RTC-backed clock with NTP sync via WiFi
Cooling — coolant temperature and fan status monitoring
Tilt Meter — vehicle tilt angle display with customisable image

The project supports both the touch and non-touch versions of the Waveshare 1.85 inch display. The expansion board is I2C connected to provide additional sensor and vehicle signal inputs. Without the expansion board the display provides clock, TPMS, tilt and incline. Add the expansion board for coolant temperature, EGT, Boost and some custom wadding and fan control specific to my Landrover. The expansion board has eight 12V safe inputs and eight outputs capable of switching automotive relays. Lots of expansion to develop your own custom functions. The gauge has an SDCard that hosts custom voice messages and the Waveshare display also supports voice input if your want to go that route.

Build Guide

Mon, 20 Apr 2026 00:00:00 +0000

Introduction

This guide walks through building a Landy Gauge from scratch. You’ll need basic soldering skills and access to a 3D printer (or a printing service).

What You’ll Need

Main Gauge

Waveshare ESP32-S3 1.85" Round Touch or non touch LCD module
Custom gauge PCB (KiCad files provided)
Components as per the BOM
3D printed case

Expansion Board (Optional)

Custom expansion board PCB
MCP23017 I/O expander
Components as per the BOM
6-wire cable (recommended: 500mm max). This is actually a Bambu labs AMS interconnect cable.
3D printed case

Sensors

EGT: K-type thermocouple. These are pretty standard. I used a generic K-type thermocouple from Amazon.
Boost: MAP sensor (0.5V–4.5V output). There are many options but I went with a FEDLDM187 which is used by Renault
TPMS: BLE tyre pressure sensors (4x). Any generic BLE sensor will work but you might need to change the format string used for reading. The specific ones I went for are AIYATO BLE TPMS from Amazon

Assembly Steps

1. PCB Assembly

I had all my PCB manufactured by PCBWay in China. It was fast and cheap with great results. I had them populate the boards for the supply and expansion board as they use SMD parts. The expansion board i did just as a desktop test board so had screw terminals for connections. My intension was to produce a smaller specific board for the final gauge but it didn’t turn out to be a high priority. I asked PCBWay not to populate the screw terminals so that I could solder wires directly to the connections to use in the Landrover. You could keep the screw terminals in the car but should seal the screw with some wax to stop them vibrating loose. A Landroiver vibrates a lot so I went for the solderd connections. The Fan Relay PCB layout can be improved a lot and I forgot to put pads on the vias I used for wire links to be able to use a single sided board. It also uses a thicker Cu layer to handle the current. If you go the fan control route don’t go with the layout as is…

Firmware

Mon, 20 Apr 2026 00:00:00 +0000

Overview

The firmware is written in C using the ESP-IDF v5.5.1 framework with LVGL v8.2 for the graphics. It runs on the ESP32-S3 with PSRAM.

Source Code

The full firmware source is available on GitHub:

LandyGauge Firmware on GitHub

Features

Display Gauges

Clock — RTC-backed with NTP time sync and timezone support (34 zones)
Boost Gauge — turbo boost pressure from MAP sensor (ADS1115 ADC)
EGT — exhaust gas temperature via K-type thermocouple (MCP9600)
Cooling Status — coolant level and fan speed indicators. Coolant temperature from Defender temperature sender.
TPMS - Tire preasure monitor supporting 4 BTLE sensors
Tilt Meter — lateral tilt angle
Inclinometer — pitch angle from IMU
Compass — digital heading with lubber line, bearing display, magnetometer calibration
Artificial Horizon — visual pitch/roll indicator (currently commented out of the gauge sequense)

System Features

Night Mode — automatic day/night switching via expansion board (headlights) or solar twilight calculation
Custom Images — load personalised vehicle images from SD card
WiFi — WPA2 connection for NTP time sync. Tried once a day to sync on home wifi and can be commanded to sync via smart phone hotspot. Selectable timezone for global use with automatic daylight saving.
Audio — warning beeps via I2S amplifier. Voice warnings for critical events.
Touch — capacitive touch for menu navigation with Touch version of Waveshare display
Settings — persistent calibration and configuration via NVS

Building the Firmware

Prerequisites

ESP-IDF v5.5.1
USB-C cable to the ESP32-S3 module

Build & Flash

# Source the ESP-IDF environment
source ~/esp/v5.5.1/esp-idf/export.sh

# Build
idf.py build

# Flash (adjust port as needed)
idf.py -p /dev/tty.usbmodem21301 flash

# Monitor serial output
idf.py -p /dev/tty.usbmodem21301 monitor

Configuration

The gauge is configured through screen menus. Key settings include:

Hardware

Mon, 20 Apr 2026 00:00:00 +0000

Main Gauge Board

The gauge is built around the Waveshare ESP32-S3 1.85" Round LCD module, with a custom PCB providing sensor connections and power management.

Key Components

Component	Purpose
ESP32-S3 (N16R8)	Main processor with WiFi and BLE
PCF85063	Real-time clock (battery backed)
QMI8658	6-axis IMU (accelerometer + gyroscope)
MAX98357A	I2S audio amplifier (warning beeps)

Downloads — Gauge Supply PCB

The power supply and interconnect PCB fits inside the 52mm gauge housing alongside the Waveshare module. KiCad project files and manufacturing outputs:

Project Launch

Mon, 20 Apr 2026 00:00:00 +0000

The Landy Gauge project is now open source — firmware, schematics, and 3D models all available.

User Manual

Mon, 20 Apr 2026 00:00:00 +0000

Overview

The Landy Gauge is a compact round instrument display designed for Land Rover vehicles. It features a 360×360 pixel circular screen with touch input, physical navigation buttons, and an expansion board for vehicle signal inputs and outputs.

The gauge provides eight display screens that cycle in order:

Clock
Boost (turbo boost pressure)
EGT (exhaust gas temperature)
Cooling (fan status, coolant level, coolant temperature)
Tire Pressure (BLE TPMS)
Tilt (vehicle roll angle / inclinometer)
Incline (vehicle pitch angle)
Compass (magnetic heading)

Gauges that require the expansion board (Boost, EGT, Compass, Cooling) are automatically skipped if the expansion board is not detected.