Introduction: Opel DPF Indicator & Monitor

Having a latest model of Opel car (Vauxhall in UK) with diesel engine can give you a little bit of headache.

I found myself in a situation I didn't know when my DPF (Diesel particulate filter) was being burned, and got filled completely. The only remedy then is chemical cleaning or DPF replacement (if it's too late).

You can find few examples of dealing with the fact on web, none of them I liked. Either you need to pay attention at your fuel burn rate while not driving or cut wires & solder to mount 12V LED which is lit while rear windows heating starts.

I thought why not to use OBD/ELM237 bluetooth reader that was already in place?

Thanks to great Elmduino library and support from it's creator - PowerBroker2 I finally achieved my goal.

The minimum cost of this setup is 15 USD (5 for cheapest OBD reader + 10 USD for wemos lolin32), although you can go as low as 10 USD if you need just a blinking LED (simplest ESP32) while DPF is burnt

The board is tested on my Opel Zafira C with engine code B20DTH (2.0/170HP), but I tested same PIDs work also with B16DTH (Zafira C tourer 1.6/136HP) using Torque app. As far as I know It should work with same engines in Opel Insignia.

PIDs were taken from this forum

Step 1: Get All the Parts You Need

1. ESP32 with built-in OLED display (I used Wemos Lolin32 board)

2. Arduino IDE

3. USB cable (mini port)

4. Fuse tap guide (optional)

5. 12V to 5V converter (optional)

Step 2: Prepare the Environment

I used very useful guide to get WEMOS Lolin32 working posted in this instructable :
ESP32 with integrated OLED

With above guide you should finish with Arduino IDE & SSD1306 libraries (for OLED) installed

You just need to install ELMduino library by PowerBroker2 from Arduino Tools/Manage Libraries section

Step 3: Configure the Board

Load the attached sketch

Modify the sketch to reflect your OBD reader name (mine is V-LINK)

Don't forget to put images.h library in project's folder if you want a fancy Opel logo at startup :)

The sketch can be easily modified to run on pure ESP32 module (without OLED screen) and just blink blue LED when DPF burns

Step 4: Mount the Board

This is only suggestion, as I prefer to have everything clean and without visible wires.

I used fuse tap + 12V to 5V converter with 2 USB outputs everything located near car fuses and hid the usb cable under the panel

Step 5: 04.04.2020 Update

Sharing another sketch for TTGO 1.14 Inch ESP32 (you can get it for 7USD), another very nice 135x240 pix display (65k colors). Tweak to your preference ;)