I wanted to create an open source electronic dashboard for my custom project car. Similar dashboards from Holley, AEM, Racepack, and other aftermarket companies can cost thousands of dollars and I think this is cost prohibitive for the average DIYer.

The System I came up with reads signals into Arduino, and then displays these signals on a cheap Nextion display. In industrial settings an Arduino would be referred to as a Programmable Logic Controller, or PLC, and the display would be a Human Machine Interface or HMI.

Currently this system is setup to read my tachometer signal and use that to drive the stock tachometer. It also reads fuel pressure and intake air temperature and shows that on the HMI display. I also setup a graph of fuel pressure over time since I needed to troubleshoot a fueling issue. It also has some automated functions such as running my engines grid heaters when the intake air temperature is low.

This system is a starting point and you could use my code and system design to create whatever controls and information display that you need. Please let me know if you endup making improvements to this project so I can make sure others can also benefit from updates. Feel free to contact me at info@buildautomedia.com.

Video 1: Fuel Pressure - Making an HMI for Arduino

Video 2: Tachometer - Using a 0.8V signal to trigger a 5V Arduino input

Video 3: Grid Heaters - Running 12V components with 5V Arduino and Measuring Temperature

Amazon Links

Here are the products I used in this project as a recommended starting point for components you may need.
Note: This links are affiliate links and any purchases made help support the website and channel.

  • Arduino Mega

    This is the standard, cheaper, version of the Rugged Arduino I used. It is up to you whether you think the standard version is needed or if your environment is harsh enough to necessitate the ruggeduino from rugged-circuits.com (no affiliation).

    Amazon Link 
  • Screw Terminal Kit for Arduino

    This allows you to convert a regular Arduino to screw terminals to make the connections much more robust. It also gives you some free prototyping space to create some small circuits.

    Amazon Link 
  • Nextion Touchscreen Display

    This is the cheap HMI touchscreen I used for my project.

    Amazon Link 
  • Wire

    Note: this wire is very soft and flexible and works well inside the enclosure. However, consider firmer wire for engine bay wiring.

    Amazon Link 
  • Inline Fuses

    For safety and reliability, all power wires should have a fuse near their source. There should never be a direct path to a battery or power supply's positive terminal without a fuse in between.

    Amazon Link 
  • Cable Glands

    for passing wires through enclosure walls and sheet metal

    Amazon Link 
  • Deutsch Connectors

    High quality connectors suitable for automotive use.

    Amazon Link 
  • Deutsch Crimpers

    Used to crimp pins onto wires before inserting them into a connector.

    Amazon Link 
  • Depinning Tool

    Used to remove pins from connectors. Keep your hand out of the line of fire when using this, I cut myself multiple times when a finger was in the wrong spot.

    Amazon Link 
  • Power Transistors

    These were used to convert voltage and signal levels between Arduino 5V logic, 0.8V triggers, and 12V. See wiring schematics and datasheets provided in the downloads.

    Amazon Link 
  • Transistor Heatsink

    If your transistors are used at a high duty cycle consider a heat sink to prevent overheating. This is unneeded for occasional switching.

    Amazon Link 
  • Resistors

    This is a broad selection of resistors which is used to create voltage dividers and in all sorts of other areas in electronics.

    Amazon Link 
  • PCB's

    These Printed Circuit Boards give you a place to create circuits and put your components.

    Amazon Link 
  • Terminal Blocks

    I used these to breakout a 5V power source within my engine bay to minimize wiring to my 5V sensors.

    Amazon Link 
  • Enclosure

    The small enclosure works well for small projects, but if you're adding multiple PCB's consider a larger size.

    Amazon Link 
  • DIN Rails

    DIN mounting is optional, but it spaces your boards off the back of the enclosure and makes them easy to add and remove as needed.

    Amazon Link 
  • DIN Mounts

    For attaching components to DIN rails

    Amazon Link 
  • Rubber Vibration Isolator

    I used these on the enclosure to protect sensitive electronics from vibrations.

    Amazon Link 
  • Pressure Sensor

    Note: This sensor failed after a few days of exposure to diesel fuel (despite claiming it was compatible). I'm still searching for a more robust sensor for measuring fuel pressure.

    Amazon Link 
  • Banjo to NPT Adapter

    Diesel fuel fittings often use banjo thru-hole style fittings. This adapter lets you add a pressure sensor to your banjo fitting. Check what types of fittings your vehicle uses and buy the appropriate adapter.

    Amazon Link 
  • Snubber Valve

    A pressure snubber protects your pressure sensor from pressure spikes, and gives more accurate readings by lowering noise. This is useful in liquid systems, but isn't needed when measuring air pressure.

    Amazon Link 
Back to blog

Leave a comment