350z Elmduino Project

This is a simple Arduino project using the ELMduino library to help diagnose information on my 350z on the track. This should work for any car that supports OBDII.

Things you'll need

1. ESP32 Board - I got this one, but there are other options out there. You just need bluetooth.
2. ELM 327 Bluetooth Module - It was cheap and seems to work well. Connects very quickly.
3. 128x64 LCD - You don't have to have an LCD for this to work but it's very helfpul for displaying the data. This article helped me get the LCD up and running on the ESP32. The LCD Pintout, I used is as follows:

// LCD hookup.
LCD | Board
SCK | D21 (SCL on board)
SDA | D22 (SDA on board)
GND | GND
VDD | 3.3v

Getting Started

1. Clone the repo
2. Select your ESP32 board and install necessary libraries
3. Create a file called arduino_secrets.h in the root directory near the index file using the template below.
4. Update the values for your MacAddress and pass code if needed see "Finding the ELM327 Mac Address)".
5. Lastly, flash the board and you're ready to try it out.

How to Run

1. With your ESP32 flashed and secrets.sh updated. Connect the ELM327 to your car.
2. Turn on the ignition.
3. Power on the device Arduino device.
4. It will begin attempting to connect. If it fails to connect try a power the device on / off (sometimes it doesn't connect the first time).
5. If you see CONNECTION SUCCESSFUL, wait a few seconds and you should see your data soon.

#define SECRET_SSID "OBD2"; // Default.
#define SECRET_PASS "1234"; // Default.

// Replace this with your own.
// Bluetooth device MAC address AA:BB:CC:11:22:33
#define SECRET_MAC_ADRESS {0xAA, 0xBB, 0xCC, 0x11, 0x22, 0x33};

Finding the ELM327 Mac Address:

1. Plugin the ELM327 unit and connect to it your computers bluetooth. It should show up as "OBDII".
2. Enter the password if it requires one. The default passcode for ELM327 bluetooth model is usually 1234. If that doesn't work, try 12345 or 0000.
3. For mac users, you can find the MAC address with the command system_profiler SPBluetoothDataType in Terminal.
4. You should be able to spot by looking for OBDII.
5. Once you have the MAC address, go to your bluetooth settings and forget "OBDII".
6. Next, update the MAC address in the arduino_secrets file. Each pair of values will have an 0x as seen below.

// AA BB CC 11 22 33
#define SECRET_MAC_ADRESS {0xAA, 0xBB, 0xCC, 0x11, 0x22, 0x33};

Troubleshooting

• Due to challenges connecting this to ELM327 wifi consistently I recommend bluetooth or a wired connection. For more details see [ELMduino Wifi Issue]](PowerBroker2/ELMduino#52).
• Make sure the car is started with OBDII ELM327 inserted into the port before starting the ESP32.
• If it doesn't connect the first time, try restarting the ESP32.
• Using the ELM_PORT.connect(ssid) as seen in the ELMduino ESP32 example often failed to connect and was very slow. I used the solution documented here to resolve this.
• Querying certain data together such as RPM and temperatures was a little slow. I didn't really need RPM anymore, so I removed it from my example. However, even with multiple other data types the temperatures displayed fluctuate a lot between the values I show here on this repo.
• If you're able to connect but your values don't load for some reason, checkout the Elmduino library and try other PIDs.